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  • 51.
    Jonker, Sybrand J. T.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Diner, Colin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Schulz, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Iwamoto, Hiroaki
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Szabó, Kálmán J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Catalytic asymmetric propargyl- and allylboration of hydrazonoesters: a metal-free approach to sterically encumbered chiral alpha-amino acid derivatives2018Inngår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 54, nr 91, s. 12852-12855Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new asymmetric catalytic propargyl- and allylboration of hydrazonoesters is reported. The reactions utilize allenyl- and allylboronic acids in the presence of the inexpensive parent BINOL catalyst. The reactions can be performed under mild conditions (0 degrees C) without any metal catalyst or other additives affording sterically encumbered chiral -amino acids. This is the first metal-free method for the asymmetric propargyl- and allylboration of hydrazonoesters.

  • 52.
    Jonsson, K. Hanna M.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Widmalm, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Methyl 4-O-benzoyl-2,3-O-isopropylidene-a-L-rhamnopyranoside2006Inngår i: Acta Crystallographica Section C: Crystal Structure Communications, ISSN 0108-2701, E-ISSN 1600-5759, Vol. 62, nr 8, s. o447-o449Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The title compound, C17H22O6, having an ester group at O4 of the hexopyranosyl sugar residue shows for the exo-cyclic C=O bond a conformation that is eclipsed to the C4-H4 bond. The two related torsion angles are denoted by syn and cis conformations. The q1 torsion angle (H4-C4-O4-C10) is indicated to have a similar conformation in solution as analyzed by NMR spectroscopy and a Karplus-type relationship.

  • 53. Kadir, K
    et al.
    Ahmed, TM
    Noréus, D
    Stockholms universitet.
    Eriksson, L
    Stockholms universitet.
    Octaammonium diaquahexa-mu 2- oxalato-dioxalatotetracopper(II) tetrahydrate2006Inngår i: Acta Crystallographica Section E-Structure Reports Online, Vol. 62, s. M1139-Artikkel i tidsskrift (Fagfellevurdert)
  • 54.
    Kaufmann, Ilana
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för matematikämnets och naturvetenskapsämnenas didaktik.
    Hamza, Karim M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för matematikämnets och naturvetenskapsämnenas didaktik.
    Rundgren, Carl-Johan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för matematikämnets och naturvetenskapsämnenas didaktik.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Developing an approach for teaching and learning about Lewis structures2017Inngår i: International Journal of Science Education, ISSN 0950-0693, E-ISSN 1464-5289, Vol. 39, nr 12, s. 1601-1624Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study explores first-year university students' reasoning as they learn to draw Lewis structures. We also present a theoretical account of the formal procedure commonly taught for drawing these structures. Students' discussions during problem-solving activities were video recorded and detailed analyses of the discussions were made through the use of practical epistemology analysis (PEA). Our results show that the formal procedure was central for drawing Lewis structures, but its use varied depending on situational aspects. Commonly, the use of individual steps of the formal procedure was contingent on experiences of chemical structures, and other information such as the characteristics of the problem given. The analysis revealed a number of patterns in how students constructed, checked and modified the structure in relation to the formal procedure and the situational aspects. We suggest that explicitly teaching the formal procedure as a process of constructing, checking and modifying might be helpful for students learning to draw Lewis structures. By doing so, the students may learn to check the accuracy of the generated structure not only in relation to the octet rule and formal charge, but also to other experiences that are not explicitly included in the formal procedure.

  • 55.
    Kerdphon, Sutthichat
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Ponra, Sudipta
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Yang, Jianping
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Wu, Haibo
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Andersson, Pher G.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi. University of KwaZulu-Natal, South Africa.
    Diastereo- and Enantioselective Synthesis of Structurally Diverse Succinate, Butyrolactone, and Trifluoromethyl Derivatives by Iridium-Catalyzed Hydrogenation of Tetrasubstituted Olefins2019Inngår i: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 9, nr 7, s. 6169-6176Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A highly efficient iridium N,P-ligand-catalyzed asymmetric hydrogenation of functionalized tetrasubstituted olefins lacking a directing group has been developed. Various structural diverse chiral succinate derivatives were obtained in high yields and excellent enantio- and diastereoselectivities (up to 99% ee) using 0.5-1.0 mol % catalyst loadings. This stereoselective reaction is applicable for the synthesis of chiral acyclic molecules (up to >99% ee) having two contiguous stereogenic centers and is compatible with various aromatic, aliphatic, and heterocyclic systems, a variety of functional groups of different electronic nature. Furthermore, this asymmetric protocol allows a short enantioselective route to the butyrolactone building block, an intermediate in the synthesis of anticancer agent BMS-871 and pharmaceuticals (2S)-(-)-Verapamil and (2S)-(-)-Gallopamil.

  • 56.
    Klingstedt, Miia
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Sundberg, Margareta
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Haigh, Sara
    Kirkland, Angus
    Gruner, Daniel
    De Backer, Annick
    Van Aert, Sandra
    Terasaki, Osamu
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Exit wave reconstruction from focal series of HRTEM images, single crystal XRD and total energy studies on SbxWO3+y (x~0.11)Artikkel i tidsskrift (Fagfellevurdert)
  • 57.
    Klingstedt, Miia
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Sundberg, Margareta
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Haigh, Sarah
    Kirkland, Angus
    Gruener, Daniel
    De Backer, Annick
    Van Aert, Sandra
    Terasaki, Osamu
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Exit wave reconstruction from focal series of hrtem images, single crystal xrd and total energy studies on sbxwo3+y (x similar to 0.11)2012Inngår i: Zeitschrift fur Kristallographie, ISSN 0044-2968, Vol. 227, nr 6, s. 341-349Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new tungsten bronze in the Sb-W-O system has been prepared in a solid state reaction from Sb2O3, WO3 and W metal powder. The average structure was determined by single crystal X-ray diffraction. SbxWO3+y (x similar to 0.11) crystallizes in the orthorhombic space group Pm2(1)n (no. 31), a = 27.8135(9) angstrom, b = 7.3659(2) angstrom and c = 3.8672(1) angstrom. The structure belongs to the (n)-ITB class of intergrowth tungsten bronzes. It contains slabs of hexagonal channels formed by six WO6 octahedra. These slabs are separated by three layers of WO6 octahedra that are arranged in a WO3-type fashion. The WO6 octahedra share all vertices to build up a three-dimensional framework. The hexagonal channels are filled with Sb atoms to similar to 80% and additional 0 atoms. The atoms are shifted out of the center of the channels. Exit-wave reconstruction of focal series of high resolution-transmission-electron-microscope (HRTEM) images combined with statistical parameter estimation techniques allowed to study local ordering in the channels. Sb atoms in neighbouring channels tend to be displaced in the same direction, which is in agreement with total energy calculations on ordered structure models, but the ratio of the occupation of the two possible Sb sites varies from channel to channel. The structure of SbxWO3+y exhibits pronounced local modulations.

  • 58. Kushwaha, Khushbu
    et al.
    Yu, Liyang
    Stranius, Kati
    Singh, Sandeep Kumar
    Hultmark, Sandra
    Iqbal, Muhammad Naeem
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Johnston, Eric
    Erhart, Paul
    Müller, Christian
    Börjesson, Karl
    A Record Chromophore Density in High-Entropy Liquids of Two Low-Melting Perylenes: A New Strategy for Liquid Chromophores2019Inngår i: Advanced Science, ISSN 2198-3844, Vol. 6, nr 4, artikkel-id 1801650Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Liquid chromophores constitute a rare but intriguing class of molecules that are in high demand for the design of luminescent inks, liquid semiconductors, and solar energy storage materials. The most common way to achieve liquid chromophores involves the introduction of long alkyl chains, which, however, significantly reduces the chromophore density. Here, strategy is presented that allows for the preparation of liquid chromophores with a minimal increase in molecular weight, using the important class of perylenes as an example. Two synergistic effects are harnessed: (1) the judicious positioning of short alkyl substituents, and (2) equimolar mixing, which in unison results in a liquid material. A series of 1-alkyl perylene derivatives is synthesized and it is found that short ethyl or butyl chains reduce the melting temperature from 278 degrees C to as little as 70 degrees C. Then, two low-melting derivatives are mixed, which results in materials that do not crystallize due to the increased configurational entropy of the system. As a result, liquid chromophores with the lowest reported molecular weight increase compared to the neat chromophore are obtained. The mixing strategy is readily applicable to other pi-conjugated systems and, hence, promises to yield a wide range of low molecular weight liquid chromophores.

  • 59. Lelis, Martynas
    et al.
    Milcius, Darius
    Wirth, Emmanuel
    Halenius, Ulf
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Jansson, Kjell
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Kadir, Karim
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Ruan, Juanfang
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Sato, Toyoto
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Yokosawa, Tadahiro
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Noréus, Dag
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    A mechanically switchable metal-insulator transition in Mg2NiH4 discovers a strain sensitive, nanoscale modulated resistivity connected to a stacking fault2010Inngår i: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 496, nr 02-jan, s. 81-86Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The band gap in semiconducting Mg2NiH4 was found to be dependent on subtle structural differences. This was discovered when investigating if thin film samples of Mg2NiH4 could be used in a switchable mirror or window device by utilizing a high to low temperature transition at about 510K. In powder samples; this transition between an FCC high temperature phase, with dynamically disordered NiH4-complexes, and a monoclinic distorted low temperature phase, with ordered Mg2NiH4-complexes, has been demonstrated in a mechanical reversible conductor-insulator transition (Blomqvist and Noreus (2002) [7]). Black monoclinic Mg2NiH4 powders were found to have a band gap of 1.1 eV. Pressed tablets of black monoclinic Mg2NiH4 powders are conductive, probably from doping by impurities or non-stoichiometry. Thin film Mg2NiH4 samples were produced by reacting hydrogen with magnetron sputtered Mg2Ni films on quartz glass or CaF2 substrates. The Mg2NiH4 films on the other hand were orange, transparent with a band gap of 2.2 eV and a cubic unit cell parameter almost identical to the disorder HT phase but with lower symmetry. If black Mg2NiH4 powder is heated above the phase transition at 510K and subsequently cooled down, the conductivity is lost and the powder turns brown. After this heat treatment TEM pictures revealed a multiple stacking fault having a local pseudo-cubic arrangement separating regions of monoclinic symmetry. The loss of conductivity and colour change is attributed to a higher band gap in the strained areas. The structure on each side of the stacking fault is related by a mirror plane as a consequence of the possibility for the NiH4-complexes to order with different orientations. This leads to a mismatch in the long range ordering and strain is probably creating the stacking faults. Strain is important for forming the cubic modification. A severely strained film was revealed with optical microscopy in reflected light, indicating that strain prevents it from relaxing back into the monoclinic structure. This was supported by multiple twinned red translucent Mg2NiH4 crystals grown with cubic symmetry at elevated temperatures in a LiH flux. When cooled to ambient conditions, the ""crystals"" had the same cubic symmetry as the films, probably held together by their neighbours. When they were ground to a fine powder to prepare TEM samples, they relaxed and reverted back to the conventional monoclinic unit cell. This interesting nanoscale modulated resistance could possibly be developed into novel memory devices if properly controllable.

  • 60. Llona-Minguez, Sabin
    et al.
    Desroses, Matthieu
    Ghassemian, Artin
    Jacques, Sylvain A.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Isacksson, Rebecka
    Koolmeister, Tobias
    Stenmark, Pål
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Scobie, Martin
    Helleday, Thomas
    Vinylic MIDA Boronates: New Building Blocks for the Synthesis of Aza-Heterocycles2015Inngår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 21, nr 20, s. 7394-7398Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A two-step synthesis of structurally diverse pyrrole-containing bicyclic systems is reported. ortho-Nitro-haloarenes coupled with vinylic N-methyliminodiacetic acid (MIDA) boronates generate ortho-vinyl-nitroarenes, which undergo a metal-free nitrene insertion, resulting in a new pyrrole ring. This novel synthetic approach has a wide substrate tolerance and it is applicable in the preparation of more complex drug-like molecules. Interestingly, an ortho-nitro-allylarene derivative furnished a cyclic beta-aminophosphonate motif.

  • 61. Llona-Minguez, Sabin
    et al.
    Throup, Adam
    Steiner, Emilie
    Lightowler, Molly
    Van der Haegen, Sandra
    Homan, Evert
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Stenmark, Pål
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Jenmalm-Jensen, Annika
    Helleday, Thomas
    Novel spirocyclic systems via multicomponent aza-Diels-Alder reaction2017Inngår i: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 15, nr 37, s. 7758-7764Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Here we present a two-step diastereoselective methodology building on a multicomponent aza-Diels-Alder reaction. Using previously unexplored cyclic ketones, heterocyclic amines and cyclopentadiene derivatives, we obtained novel spiro-heterocyclic frameworks at the interphase between drug-like molecules and natural products.

  • 62. Lundberg, Daniel
    et al.
    Persson, Ingmar
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    D'Angelo, Paola
    De Panfilis, Simone
    Structural Study of the N,N '-Dimethylpropyleneurea Solvated Lanthanoid(III) Ions in Solution and Solid State with an Analysis of the Ionic Radii of Lanthanoid(III) Ions2010Inngår i: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 49, nr 10, s. 4420-4432Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The structures of the N,N'-dimethylpropyleneurea (dmpu) solvated lanthanoid(III) ions have been studied in dmpu solution (La-Nd, Sm-Lu) and in solid iodide salts (La-Nd, Sm, Gd-Lu) by extended X-ray absorption fine structure (EXAFS), and single crystal X-ray diffraction (La, Pr, Nd, Gd, Tb, Er, Yb, and Lu); the EXAFS studies were performed on both K and L-III absorption edges. Because of the space-demanding properties of dmpu upon coordination, dmpu solvated metal ions often show coordination numbers lower than those found in corresponding hydrates and solvates of oxygen donor solvents without steric requirements beyond the size of the donor atom. All lanthanoid(III) ions are seven-coordinate in solution, except lutetium(III) which is six-coordinated in regular octahedral fashion, whereas in the solid iodide salts the dmpu solvated lanthanoid(III) ions are all six-coordinate in regular octahedral fashion, A comparison of Ln-O bond lengths in a large number of lanthanoid(III) complexes with neutral oxygen donor ligands and different configurations shows that the metal ion-oxygen distance is specific for each coordination number with a narrow bond distance distribution. This also shows that the radius of the coordinated oxygen atom in these compounds can be assumed to be 1.34 angstrom as proposed for coordinated water, while for ethers such as tetrahydrofuran (thf) it is somewhat larger. Using this atomic radius of oxygen in coordinated water molecules, we have calculated the ionic radii of the lanthanoid(III) ions in four- to nine-coordination and evaluated using the bond lengths reported for homo- and heteroleptic complexes in oxygen donor solvates in solution and solid state. This yields new and revised ionic radii which in some instances are significantly different from the ionic radii normally referenced in the literature, including interpolated values for the elusive promethium(III) ion.

  • 63.
    Motwani, Hitesh
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Göpfert, Lisa
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Larsen, Kristian
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Reaction kinetic studies for comparison of mutagenic potency between butadiene monoxide and glycidamide2018Inngår i: Chemico-Biological Interactions, ISSN 0009-2797, E-ISSN 1872-7786, Vol. 288, s. 57-64Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    DNA adducts can be formed from covalent binding of electrophilic reactive compounds to the nucleophilic Nand O-atoms of the biomolecule. The O-sites on DNA, with nucleophilic strength (n) of ca. 2, is recognized as a critical site for mutagenicity. Characterization of the reactivity of electrophilic compounds at the O-sites can be used to predict their mutagenic potency in relative terms. In the present study, reaction kinetic experiments were performed for butadiene monoxide (BM) in accordance with the Swain-Scott relation using model nucleophiles representing N- and O-sites on DNA, and earlier for glycidamide (GA) using a similar approach. The epoxide from the kinetic experiments was trapped by cob(I)alamin, resulting in formation of an alkylcobalamin which was analyzed by liquid chromatography tandem mass spectrometry. The Swain-Scott relationship was used to determine selectivity constant (s) of BM and GA as 0.86 and 1.0, respectively. The rate constant for the reaction at n of 2 was extrapolated to 0.023 and 0.038M(-1) h(-1) for BM and GA, respectively, implying a higher mutagenic potency per dose unit of GA compared to BM. The reaction kinetic parameters associated with mutagenic potency were also estimated by a density functional theory approach, which were in accordance to the experimental determined values. These types of reaction kinetic measures could be useful in development of a chemical reactivity based prediction tool that could aid in reduction of animal experiments in cancer risk assessment procedures for relative mutagenicity.

  • 64. Nilsson, Kersti B.
    et al.
    Maliarik, Mikhail
    Persson, Ingmar
    Fischer, Andreas
    Ullström, Ann-Sofi
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Sandström, Magnus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Coordination Chemistry of Mercury(II) in Liquid and Aqueous Ammonia Solution and the Crystal Structure of Tetraamminemercury(II) Perchlorate2008Inngår i: Inorganic Chemistry, Vol. 47, s. 1953-1964Artikkel i tidsskrift (Fagfellevurdert)
  • 65.
    Nyhlén, Jonas
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Bäckvall, Jan-Erling
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Synthesis and optical resolution of an allenoic acid by diastereomeric salt formation induced by chiral alkaloids2008Inngår i: Chirality, ISSN 0899-0042, Vol. 20, nr 1, s. 47-50Artikkel i tidsskrift (Fagfellevurdert)
  • 66.
    Nylén, Johanna
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Benson, Daryn
    Haussermann, Ulrich
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Characterization of a high pressure, high temperature modification of ammonia borane (BH3NH3)2013Inngår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 139, nr 5, s. 054507-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    At elevated pressures (above 1.5 GPa) dihydrogen bonded ammonia borane, BH3NH3, undergoes a solid-solid phase transition with increasing temperature. The high pressure, high temperature (HPHT) phase precedes decomposition and evolves from the known high pressure, low temperature form with space group symmetry Cmc2(1) (Z = 4). Structural changes of BH3NH3 with temperature were studied at around 6 GPa in a diamond anvil cell by synchrotron powder diffraction. At this pressure the Cmc2(1) phase transforms into the HPHT phase at around 140 degrees C. The crystal system, unit cell, and B and N atom position parameters of the HPHT phase were extracted from diffraction data, and a hydrogen ordered model with space group symmetry Pnma (Z = 4) subsequently established from density functional calculations. However, there is strong experimental evidence that HPHT-BH3NH3 is a hydrogen disordered rotator phase. A reverse transition to the Cmc2(1) phase is not observed. When releasing pressure at room temperature to below 1.5 GPa the ambient pressure (hydrogen disordered) I4mm phase of BH3NH3 is obtained. 

  • 67.
    Olsson, Johan D. M.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Lahmann, Martina
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Oscarson, Stefan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Investigations of glycosylation reactions with 2-N-acetyl-2N,3O-oxazolidinone-protected glucosamine donors2008Inngår i: The Journal of Organic Chemistry, ISSN 0022-3263, Vol. 73, nr 18, s. 7181-7188Artikkel i tidsskrift (Fagfellevurdert)
  • 68.
    Pathipati, Stalin R.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Selander, Nicklas
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Stereoselective synthesis of bicyclo[3.n.1]alkenone frameworks by Lewis acid-catalysis2017Inngår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 53, nr 82, s. 11353-11356Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An intermolecular cyclization of alkynyl enones with cyclic ketones for the synthesis of bicyclo[3.n.1]alkenones is reported. This protocol exhibits a high functional group tolerance and provides access to a variety of bicyclic systems found as skeletons in many natural products.

  • 69.
    Pathipati, Stalin R.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Singh, Vipender
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Selander, Nicklas
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Lewis Acid Catalyzed Annulation of Nitrones with Oxiranes, Aziridines, and Thiiranes2015Inngår i: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 17, nr 18, s. 4506-4509Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A highly selective Lewis acid catalyzed annulation of three-membered heterocycles with nitrones has been developed. Oxiranes, aziridines, and thiiranes were used as substrates for the synthesis of various six-membered heterocycles using Al or In catalysts. This catalytic protocol demonstrates a broad substrate scope and provides access to new structural motifs in high yields and in excellent selectivity under mild reaction conditions.

  • 70.
    Pathipati, Stalin R.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    van der Werf, Angela
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Selander, Nicklas
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Diastereoselective Synthesis of Cyclopenta[c]furans by a Catalytic Multicomponent Reaction2016Inngår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 55, nr 39, s. 11863-11866Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A diastereoselective three-component reaction between alkynyl enones, aldehydes and secondary amines is reported. With the aid of a benign indium catalyst, a range of highly substituted cyclopenta[c]furan derivatives can be obtained in a single-step procedure. The formation of the stereodefined heterocyclic motifs takes place via in situ generation of enamines followed by two sequential cyclization steps.

  • 71.
    Pendrill, Robert
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Widmalm, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Methyl 4-O-benzyl-alpha-l-rhamno-pyrano-side2014Inngår i: Acta Crystallographica Section E: Structure Reports Online, ISSN 1600-5368, E-ISSN 1600-5368, Vol. 70, s. o561-o562Artikkel i tidsskrift (Fagfellevurdert)
  • 72. Persson, Ingmar
    et al.
    D'Angelo, Paola
    De Panfilis, Simone
    Sandström, Magnus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Hydration of Lanthanoid(III) ions in Aqueous Solution and Crystalline Hydrates Studied by EXAFS Spectroscopy and Crystallography: The Myth of the2008Inngår i: Chemistry - A European Journal, ISSN 0947-6539, Vol. 14, s. 3056-3066Artikkel i tidsskrift (Fagfellevurdert)
  • 73. Persson, Ingmar
    et al.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Lindqvist-Reis, Patric
    Persson, Per
    Sandström, Magnus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    An EXAFS Spectroscopic, Large Angle X-Ray Scattering and Crystallo¬graphic Study of the Hexahydrated and the Dimethyl Sulfoxide and Pyridine-1-Oxide Hexasolvated Mercury(II) Ions2008Inngår i: Chemistry, A European Journal, Vol. 14, s. 6687-6696Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    The structure of the solvated mercury(II) ion in aqueous and dimethyl sulfoxide solution has been studied by means of large angle X-ray scattering (LAXS) and EXAFS tech¬niques. The distribution of the Hg-O bond distances is unusually wide and asymmetric in both solvents. In aqueous solution hexahydrated [Hg(OH2)6]2+ ions in distorted octahedral configuration, with the centroid of the Hg-O bond distances at 2.38(1) Å, are surrounded by a diffuse second hydration sphere, with HgOII distances around a mean value of 4.20(2) Å. In dimethyl sulfoxide solution the six Hg-O and HgS distances of the hexasolvated Hg(OS(CH3)2)6]2+ complex are centered around 2.38(1) and 3.45(2) Å, respectively. The crystal structure of hexakis¬(pyridine-1-oxide)mercury(II) perchlorate has been re-determi¬ned at 100 K. The space group R implies six equal Hg-O bond distances of 2.3416(7) Å for the Hg(ONC5H5)62+ complex, as also for the hexaaquamercury(II) perchlorate and hexakis(dimethyl sulfoxide)mercury(II) trifluoro¬methanesulfonate compounds, according to previous crystallographic results. However, EXAFS results for those compounds in all cases reveal strongly asymmetric Hg-O bond distance distributions. Vibronic coupling of close valence states in a so-called Pseudo Jahn-Teller Effect probably induces the distorted configurations.

  • 74. Persson, Ingmar
    et al.
    Lyczko, Krzysztof
    Lundberg, Daniel
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Placzek, Anna
    Coordination Chemistry Study of Hydrated and Solvated Lead(II) Ions in Solution and Solid State2011Inngår i: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 50, nr 3, s. 1058-1072Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The coordination chemistry of lead(II) in the oxygen donor solvents water, dimethylsulfoxide (dmso, Me(2)SO), N,N-dimethylformamide (dmf), N,N-dimethylacetamide (dma), N,N'-dimethylpropyleneurea (dmpu), and 1,1,3,3-tetramethylurea (tmu), as well as in the sulfur donor solvent N,N-dimethylthioformamide (dmtf), has been investigated by extended X-ray absorption fine structure (EXAFS) and/or large angle X-ray scattering (LAXS) in solution, and by single crystal X-ray diffraction and/or EXAFS of solid hydrates and solvates. Lead(II) may either form hemidirected complexes with large bond distance distribution and an apparent gap for excess electron density, or holodirected ones with a symmetric coordination sphere with normal bond distance distribution, depending on the strength of antibonding lead 6s/ligand np molecular orbital interactions and ligand-ligand interactions. The crystallographic data show that the solid lead(II) perchlorate and trifluoromethanesulfonate hydrate structures are hemidirected, while the solid lead(II) solvates of dma and dmpu have regular octahedral configuration with holodirected geometry and mean Pb-O bond distances in the range 2.50-2.52 A. EXAFS data on the hydrated lead(II) ion in aqueous solution show broad bond distance distribution and a lack of inner-core multiple scattering contributions strongly indicating a hemidirected structure. The Pb-O bond distances found both by EXAFS and LAXS, 2.54(1) angstrom, point to a six-coordinate hydrated lead(II) ion in hemidirected fashion with an unevenly distributed electron density. The results obtained for the dmso solvated lead(II) ion in solution are ambiguous, but for the most part support a six-coordinate hemidirected complex. The mean Pb-O bond distances determined in dmf and dma solution by LAXS, 2.55(1) and 2.48(1) angstrom, respectively, indicate that in both solvate complexes lead(II) binds six solvent molecules with the former complex being hemidirected whereas the latter is holodirected. The dmpu and tmu solvated lead(II) ions have a regular holodirected octahedral configuration, as expected given their space-demanding characteristics and ligand-ligand intermolecular interactions. The dmtf solvated lead(II) ion in solution is most likely five-coordinate in a hemidirected configuration, with a mean Pb-S bond distance of 2.908(4) angstrom. New and improved ionic radii for the lead(II) ion in 4-8-coordination in hemi and holodirected configurations are proposed using crystallographic data.

  • 75.
    Rabten, Wangchuk
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Margarita, Cristiana
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Andersson, Pher G.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Ir-Catalyzed Asymmetric and Regioselective Hydrogenation of Cyclic Allylsilanes and Generation of Quaternary Stereocenters via the Hosomi-Sakurai Allylation2018Inngår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 24, nr 7, s. 1681-1685Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A number of cyclic dienes containing the allylsilane moiety were prepared via Birch reduction and subjected to iridium-catalyzed regioselective and asymmetric hydrogenation, which provided chiral allylsilanes in high conversion and enantiomeric excess (up to 99 % ee). The compounds were successively used in the Hosomi-Sakurai allylation with various aldehydes employing TiCl4 as Lewis acid, providing adducts with two additional stereogenic centers in excellent diastereoselectivity.

  • 76.
    Ramstadius, Clinton
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Hekmat, Omid
    Department of Biochemistry, Lund University.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi, Avdelningen för strukturkemi.
    Stålbrand, Henrik
    Department of Biochemistry, Lund University.
    Cumpstey, Ian
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    β-Mannosidase and β-hexosaminidase inhibitors: synthesis of 1,2-bis-epi-valienamine and 1-epi-2-acetamido-2-deoxy-valienamine from D-mannose2009Inngår i: Tetrahedron: asymmetry, ISSN 0957-4166, E-ISSN 1362-511X, Vol. 20, nr 6-8, s. 795-807Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A partially protected C-5C-5a unsaturated carbasugar with α-lyxo configuration is synthesised in five steps and 26% overall yield from a known mannose-derived hemiacetal, using ring-closing metathesis as a key step. This carbasugar is converted into valienamine derivatives with β-lyxo (i.e., corresponding to β-manno at C-1–C-4), α-lyxo (i.e., corresponding to α-manno at C-1–C-4) and β-2-acetamido-2-deoxy-xylo (i.e., corresponding to β-GlcNAc at C-1–C-4) configurations. This is the first report of the synthesis of the β-lyxo compound, 1,2-bis-epi-valienamine, which was found to inhibit Cellulomonas fimi β-mannosidase (CfMan2A) with Ki 140 μM. We report the crystal structures of three protected C-5C-5a unsaturated carbasugars with lyxo configuration.

  • 77.
    Risberg, Emiliana, Damian
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Mink, Janos
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Pettersson, Lars G. M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Fysikum.
    Skripkin, Mikhail Yu.
    Sandström, Magnus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Sulfur X-ray absorption and vibrational spectroscopic study of sulfite, sulfur dioxide and sulfonate solutions, and of the substituted sulfonate ions X3CSO3- (X = H, Cl, F)2007Inngår i: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 46, nr 20, s. 8332-8348Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Sulfur K-edge X-ray absorption near-edge structure (XANES) spectra have been recorded and the S(1s) electron excitations evaluated by means of density functional theory−transition potential (DFT−TP) calculations to provide insight into the coordination, bonding, and electronic structure. The XANES spectra for the various species in sulfur dioxide and aqueous sodium sulfite solutions show considerable differences at different pH values in the environmentally important sulfite(IV) system. In strongly acidic (pH < 1) aqueous sulfite solution the XANES spectra confirm that the hydrated sulfur dioxide molecule, SO2(aq), dominates. The theoretical spectra are consistent with an OSO angle of 119° in gas phase and acetonitrile solution, while in aqueous solution hydrogen bonding reduces the angle to 116°. The hydration affects the XANES spectra also for the sulfite ion, SO32-. At intermediate pH (4) the two coordination isomers, the sulfonate (HSO3-) and hydrogen sulfite (SO3H-) ions with the hydrogen atom coordinated to sulfur and oxygen, respectively, could be distinguished with the ratio HSO3-:SO3H- about 0.28:0.72 at 298 K. The relative amount of HSO3- increased with increasing temperature in the investigated range from 275 to 343 K. XANES spectra of sulfonate, methanesulfonate, trichloromethanesulfonate, and trifluoromethanesulfonate compounds, all with closely similar S−O bond distances in tetrahedral configuration around the sulfur atom, were interpreted by DFT−TP computations. The energy of their main electronic transition from the sulfur K-shell is about 2478 eV. The additional absorption features are similar when a hydrogen atom or an electron-donating methyl group is bonded to the −SO3 group. Significant changes occur for the electronegative trichloromethyl (Cl3C−) and trifluoromethyl (F3C−) groups, which strongly affect the distribution especially of the π electrons around the sulfur atom. The S−D bond distance 1.38(2) Å was obtained for the deuterated sulfonate (DSO3-) ion by Rietveld analysis of neutron powder diffraction data of CsDSO3. Raman and infrared absorption spectra of the CsHSO3, CsDSO3, H3CSO3Na, and Cl3CSO3Na·H2O compounds and Raman spectra of the sulfite solutions have been interpreted by normal coordinate calculations. The C−S stretching force constant for the trichloromethanesulfonate ion obtains an anomalously low value due to steric repulsion between the Cl3C− and −SO3 groups. The S−O stretching force constants were correlated with corresponding S−O bond distances for several oxosulfur species.

  • 78. Sanandaji, N.
    et al.
    Ovaskainen, L.
    Gunnewiek, M. Klein
    Vancso, G. J.
    Hedenqvist, M. S.
    Yu, S.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Roth, S. V.
    Gedde, U. W.
    Unusual crystals of poly(epsilon-caprolactone) by unusual crystallisation: The effects of rapid cooling and fast solvent loss on the morphology, crystal structure and melting2013Inngår i: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 54, nr 5, s. 1497-1503Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The lateral habit, unit cell structure and melting behaviour of single crystals of poly(epsilon-caprolactone) (PCL) prepared by the rapid expansion of a supercritical solution technique was studied by AFM at ambient and higher temperatures and by grazing-incident X-ray scattering using a synchrotron source. After dissolving PCL in a solution of supercritical CO2 and 0.1 vol.% chloroform, an extremely fast phase transfer from a supercritical to a gas-like state occurred during expansion into atmospheric conditions, leading to a temporary temperature drop to below -;50 degrees C at the silica surface where the crystals were deposited. Single crystals of a hitherto unreported rectangular lateral habit were observed. Six-sided crystals were also observed, but they were fewer than the rectangular crystals and in addition the angles between the lateral faces were different from the theoretical angles between adjacent {110} faces and {110} and {100} faces. X-ray scattering indicated a polymorphic structure also including the orthorhombic (110) and (200) diffraction peaks. Distinct low angle peaks essentially along the c-axis indicated a stacking on a very fine scale (3.7-4.7 nm) within the crystals. The equatorial diffraction peaks indicated a less dense packing of the PCL stems. Rectangular single crystals with a height according to AFM of 11-27 nm melted between 40 and 45 degrees C, which is lower than the melting points (55 degrees C) recorded for the distorted six-sided crystals. The unusual conditions for crystallisation used gave the polymer molecules a severe limitation to rearrange from the initial random coil state. The facetted crystals consisted of a stack of 4 nm thick blocks; these blocks most probably constituted a regular variation in molecular packing, i.e. molecular order. The pronounced changes in the angles between adjacent faces from those observed in mature PCL crystals and the wide-angle X-ray scattering data indicated the presence of conformational disorder in the crystals.

  • 79. Sawadjoon, Supaporn
    et al.
    Orthaber, Andreas
    Sjöberg, Per J. R.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Samec, Joseph S. M.
    Equilibrium Study of Pd(dba)(2) and P(OPh)(3) in the Pd-Catalyzed Allylation of Aniline by Allyl Alcohol2014Inngår i: Organometallics, ISSN 0276-7333, E-ISSN 1520-6041, Vol. 33, nr 1, s. 249-253Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Reaction of Pd(dba)(2) and P(OPh)(3) shows a unique equilibrium where the Pd[P(OPh)(3)](3) complex is favored over both Pd(dba)[P(OPh)(3)](2) and Pd[P(OPh)(3)](4) complexes at room temperature. At a lower temperature, Pd[P(OPh)(3)](4) becomes the most abundant complex in solution. X-ray studies of Pd[P(OPh)(3)](3) and Pd(dba)[P(OPh)(3)](2) complexes show that both complexes have a trigonal geometry with a Pd-P distance of 2.25 angstrom due to the pi-acidity of the phosphite ligand. In solution, pure Pd(dba)[P(OPh)(3)](2) complex equilibrates to the favored Pd[P(OPh)(3)](3) complex, which is the most stable complex of those studied, and also forms the most active catalytic species. This catalyst precursor dissociates one ligand to give the reactive Pd[P(OPh)(3)](2), which performs an oxidative addition of nonmanipulated allyl alcohol to generate the pi-allyl-Pd[P(OPh)(3)](2) intermediate according to ESI-MS

  • 80.
    Sharafat, Ali
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Berastegui, Pedro
    Esmaeilzadeh, Saeid
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Grins, Jekabs
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    A cubic calcium oxynitrido-silicate, Ca2.88Si2N1.77O4.23Artikkel i tidsskrift (Fagfellevurdert)
  • 81. Sharafat, Ali
    et al.
    Berastegui, Pedro
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Esmaeilzadeh, Saeid
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Grins, Jekabs
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    A cubic calcium oxynitrido-silicate, Ca(2.89)Si(2)N(1.76)O(4.24)2011Inngår i: Acta Crystallographica Section E: Structure Reports Online, ISSN 1600-5368, E-ISSN 1600-5368, Vol. 67, nr 11, s. i66-+Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The title compound, tricalcium oxynitride silicate, with composition Ca(3-x)Si(2)N(2-2x)O(4+2x) (x similar or equal to 0.12), is a perovskite-related calcium oxynitrido silicate containing isolated oxynitrido silicate 12-rings. The N atoms are statistically disordered with O atoms (occupancy ratio N:O = 0.88:0.12) and occupy the bridging positions in the 12 ring oxynitrido silicate anion, while the remaining O atoms are located at the terminal positions of the Si(O,N)(4) tetrahedra. The majority of the Ca(2+) cations fill the channels along [100] in the packing of the 12-ring anions. The rest of these cations are located at several positions, with partial occupancy, in channels along the body diagonals.

  • 82. Sharma, Sanjeev
    et al.
    Lombeck, Florian
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Johansson, Olof
    Resolution of Conformationally Chiral mer-[Ru(dqp)2]2+ and Crystallographic Analysis of [δ,δ-Ru(dqp)2][Δ-TRISPHAT]2 (dqp=2,6-Di(quinolin-8-yl)pyridine; TRISPHAT=Tris(tetrachlorocatecholate)phosphate)2010Inngår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 16, nr 24, s. 7078-7081Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Resolving the problem! The conformationally chiral bistridentate [Ru(dqp)2]2+ complex (dqp=2,6-di(quinolin-8-yl)pyridine) was resolved by selective precipitation using [Δ-TRISPHAT] (tris(tetrachlorocatecholate)phosphate) as the chiral auxiliary. The X-ray crystal structure of one diastereomer has been solved (see picture). No evidence for racemization was observed either at elevated temperature or with visible light.

  • 83.
    Shatskiy, Andrey
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Bardin, Andrey A.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Oschmann, Michael
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Matheu, Roc
    Benet-Buchholz, Jordi
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Kärkäs, Markus D.
    Johnston, Eric
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Gimbert-Suriñach, Carolina
    Llobet, Antoni
    Åkermark, Björn
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Electrochemically Driven Water Oxidation by a Highly Active Ruthenium-Based Catalyst2019Inngår i: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 12, nr 10, s. 2251-2262Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The highly active ruthenium-based water oxidation catalyst [Ru-X(mcbp)(OHn)(py)(2)] [mcbp(2-)=2,6-bis(1-methyl-4-(carboxylate)benzimidazol-2-yl)pyridine; n=2, 1, and 0 for X=II, III, and IV, respectively], can be generated in a mixture of Ru-III and Ru-IV states from either [Ru-II(mcbp)(py)(2)] or [Ru-III(Hmcbp)(py)(2)](2+) precursors. The precursor complexes are isolated and characterized by single-crystal X-ray analysis, NMR, UV/Vis, EPR, and FTIR spectroscopy, ESI-HRMS, and elemental analysis, and their redox properties are studied in detail by electrochemical and spectroscopic methods. Unlike the parent catalyst [Ru(tda) (py)(2)] (tda(2-)=[2,2:6,2-terpyridine]-6,6-dicarboxylate), for which full transformation into the catalytically active species [Ru-IV(tda)(O)(py)(2)] could not be carried out, stoichiometric generation of the catalytically active Ru-aqua complex [Ru-X(mcbp)(OHn)(py)(2)] from the Ru-II precursor was achieved under mild conditions (pH7.0) and short reaction times. The redox properties of the catalyst were studied and its activity for electrocatalytic water oxidation was evaluated, reaching a maximum turnover frequency (TOFmax) of around 40000s(-1) at pH9.0 (from foot-of-the-wave analysis), which is comparable to the activity of the state-of-the-art catalyst [Ru-IV(tda)(O)(py)(2)].

  • 84. Singh, Pradyumna S.
    et al.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Lomoth, Reiner
    (I,0) Mixed-Valence State of a Diiron Complex with Pertinence to the [FeFe]-Hydrogenase Active Site: An IR, EPR, and Computational Study2009Inngår i: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 48, nr 23, s. 10883-10885Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Biphenyl-2,2′-dithiolate (bpdt) bridged Fe2(bpdt)(CO)6 (1) undergoes two sequential electrochemically quasi-reversible reductions. The one-electron reduction product 1 is unusually stable against irreversible structural changes and could be characterized by IR and EPR spectroscopy supported by computational methods. Reduction to the (I,0) state does not trigger bridging coordination of CO but partial deligation of the dithiolate in 1 that ultimately forms a diamagnetic dimerization product.

  • 85.
    Sundén, Henrik
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Rios, Ramón
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Ibrahem, Ismail
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Zhao, Gui-Ling
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Córdova, Armando
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    A highly enantioselective catalytic domino aza-Michael/aldol reaction: one-pot organocatalytic asymmetric synthesis of 1,2-dihydroquinolidines2007Inngår i: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 349, s. 827-832Artikkel i tidsskrift (Fagfellevurdert)
  • 86.
    Sundén, Henrik
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Rios, Ramón
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Xu, Yongmei
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Córdova, Armando
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Direct enantioselective synthesis of bicyclic Diels-Alder products2007Inngår i: Advanced Synthesis & Catalysis, ISSN 1615-4150, Vol. 349, s. 2549-2555Artikkel i tidsskrift (Fagfellevurdert)
  • 87.
    Svensson, Gunnar
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    BaNb4-xTixO6 (x = 0.53)1999Inngår i: Acta Crystallographica Section C: Crystal Structure Communications, ISSN 0108-2701, E-ISSN 1600-5759, Vol. C55, s. 17-19Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The title compound, barium niobium titanium oxide, is isostructural with BaNb4O6, i.e. it contains alternating NbO and perovskite-type single slabs. The NbO slabs can alternatively be described as layers of Nb6O12 clusters, condensed via corner sharing among the central Nb6 octahedra.

  • 88.
    Svensson, Gunnar
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    ERIKSSON, LARS
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    The Crystal Structure of SrNb4O61995Inngår i: Journal of Solid State Chemistry, ISSN 0022-4596, E-ISSN 1095-726X, Vol. 114, s. 301-307Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Single crystals of SrNb4O6 were obtained by heat treatment of a pelleted mixture of Sr5Nb4O15, Nb2O5, and Nb at 1670 degrees C in sealed Nb tubes. High-resolution electron microscopy (HREM) studies showed the structure to be an intergrowth of alternating slabs of SrNbO3 (perovskite-type structure) and NbO (ordered deficient NaCl-type structure), both two unit cells wide. SrNb4O6 has a tetragonal unit cell with a = 4.1655(3) Angstrom and c = 16.223(1) Angstrom and space group P4/mmm, Z = 2. The structure model obtained from the HREM images was refined, using single-crystal diffraction data, to R(f) = 3.0%

  • 89.
    Svensson, Gunnar
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Olofsson, Christer
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Holm, William
    Studies on Ba2Nb5−xTixO9 (0≤x≤1.75)1997Inngår i: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 248, nr 1-2, s. 33-41Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The structure of Ba2Nb5O9 can be described as an intergrowth between perovskite- (BaNbO3) and NbO-type slabs. The substitution of Ti for Nb according to the formula Ba2Nb5−xTixO9 (0.00≤x≤1.75) has been investigated. The decrease in unit cell parameters as a function of overall composition determined by microanalysis shows the maximum value of x to be around 0.9. At higher x values increasing amounts of BaNb1−xTixO3 and Nb were found. Rietveld refinements of the structure using X-ray powder diffraction data show Ti to prefer Nb positions in the perovskite slab (NbO6 octahedra) and the Nb positions in the NbO slab closest to the perovskite slabs. This latter Nb is five-fold coordinated by oxygen atoms, forming a square pyramid. The third Nb position, in the middle of the NbO slab with a square planar coordination of oxygen atoms, remains undoped.

    The electrical resistivity and magnetic susceptibility of the x = 0.0, 0.25, 0.50 and 0.75 samples were measured. All samples were found to be metallic conductors and temperature-independent paramagnetic.

  • 90. Torapava, Natallia
    et al.
    Persson, Ingmar
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Lundberg, Daniel
    Hydration and Hydrolysis of Thorium(IV) in Aqueous Solution and the Structures of Two Crystalline Thorium(IV) Hydrates2009Inngår i: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 48, nr 24, s. 11712-11723Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Solid octaaqua(kappa O-2-perchlorato)thorium(IV) perchlorate hydrate, [Th(H2O)(8)(ClO4)](ClO4)(3)center dot H2O, 1, and aqua-oxonium hexaaquatris(kappa O-trifluoromethanesulfonato)thorium(IV) trisaquahexakis(kappa O-trifluoromethanesulfonato)-thorinate(IV), H5O2[Th(H2O)(6)(OSO2CF3)(3)][Th(H2O)(3)(OSO2CF3)(6)], 2, were crystallized from concentrated perchloric and trifluoromethanesulfonic acid solutions, respectively. 1 adopts a severely distorted tricapped trigonal prismatic configuration with an additional oxygen from the perchlorate ion at a longer distance. 2 consists of individual hexaaquatris(kappa O-trifluoromethanesulfonato)thorium(IV) and trisaquahexakis(kappa O-trifluoromethanesulfonato)thorinate(IV) ions and an aquaoxonium ion bridging these two ions through hydrogen bonding. The hydrated thorium(IV) ion is nine-coordinated in aqueous solution as determined by extended X-ray absorption fine structure (EXAFS) and large angle X-ray scattering (LAXS). The LAXS studies also showed a second hydration sphere of about 18 water molecules, and traces of a 3rd hydration sphere. Structural studies in aqueous solution of the hydrolysis products of thorium(IV) have identified three different types of hydrolysis species: a mu O-2-hydroxo dimer, [Th-2(OH)(2)(H2O)(12)](6+), a mu O-2-hydroxo tetramer, [Th-4(OH)(8)(H2O)(16)](8+), and a mu O-3-oxo hexamer, [Th6O8(H2O)(n)](8+). Detailed structures of these three hydrolysis species are given A compilation of reported solid state structures of actinoid(IV) compounds with oxygen donor ligands show a strong correlation between the An-O bond distance and the coordination number. The earlier reported U-O bond distance in the hydrated uranium(IV) ion in aqueous solution, confirmed in this study, is related to nine-coordination. The hydrated tri- and tetravalent actinoid ions in aqueous solution all seem to be nine-coordinated The trivalent ions show a significant difference in bond distance to prismatic and capping water molecules in assumed tricapped trigonal prismatic configuration, while the tetravalent ions seem to form more regular structures, probably because of higher polarization.

  • 91.
    Tran, Lien-Hoa
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Sun, Licheng
    Åkermark, Björn
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    A new square planar mononuclear MnIII complex for catalytic epoxidation of stilbene2008Inngår i: Journal of Organometallic Chemistry, ISSN 0022-328X, Vol. 693, nr 6, s. 1150-1153Artikkel i tidsskrift (Fagfellevurdert)
  • 92.
    Vesely, Jan
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Rios, Ramón
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Ibrahem, Ismail
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Zhao, Gui-Ling
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Córdova, Armando
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    One-pot catalytic asymmetric cascade synthesis of cycloheptane derivatives2008Inngår i: Chemistry: a European journal, ISSN 0947-6539, Vol. 14, nr 9, s. 2693-2698Artikkel i tidsskrift (Fagfellevurdert)
  • 93. Weis, Franz A.
    et al.
    Lazor, Peter
    Skogby, Henrik
    Stalder, Roland
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Polarized IR and Raman spectra of zoisite: insights into OH-dipole orientation and the luminescence2016Inngår i: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 38, nr 3, s. 537-543Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The OH-dipole in the mineral zoisite has been a topic of discussion regarding its general orientation and vibrational modes. We present new polarized single-crystal Raman and infrared spectra and verify the orientation of the OH-dipole along the crystallographic c axis with a slight deviation towards the crystallographic a axis. Polarized Raman and FTIR spectra confirm that the OH band at 3150 cm(-1) corresponds to the O(10)-H center dot center dot center dot O(4) hydrogen bridge and exclude a previously suggested second hydrogen bridge O(10)-H center dot center dot center dot O(2). Further, Raman spectra provide insights on the luminescence of zoisite and the interference of luminescence peaks in the OH-region.

  • 94. Xu, Yunhua
    et al.
    Åkermark, Torbjörn
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Gyollai, Viktor
    Zou, Dapeng
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Duan, Lele
    Zhang, Rong
    Åkermark, Björn
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Sun, Licheng
    A New Dinuclear Ruthenium Complex as an  Efficient for Water Oxidation Catalyst2009Inngår i: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 48, nr 7, s. 2717-2719Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A dinuclear ruthenium complex, which acts as a molecular catalyst for water oxidation, has been synthesized and characterized. The electronic and electrochemical properties were studied by UV−vis spectroscopy and cyclic voltammetry. The oxidation potentials of the complex are significantly lowered by introducing a negatively charged carboxylate ligand, in comparison with those of the reported complexes that have neutral ligands. The catalytic activity of the complex toward water oxidation using Ce(NH4)2(NO3)6 as a chemical oxidant was investigated by means of an oxygen electrode and mass spectrometry. The turnover number of this catalyst with CeIV as the chemical oxidant was found to be ca. 1700. The mass spectroscopic analysis of the isotopomer distribution in oxygen evolved from 18O-labeled water indicates that O atoms in the evolved oxygen originate from water

  • 95. Yang, Kan
    et al.
    Melcher, Charles L.
    Rack, Philip D.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för oorganisk kemi och strukturkemi.
    Effects of Calcium Codoping on Charge Traps in LSO:Ce Crystals2009Inngår i: IEEE Transactions on Nuclear Science, ISSN 0018-9499, E-ISSN 1558-1578, Vol. 56, nr 5, s. 2960-2965Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Experimental studies of Lu2SiO5 : Ce (LSO:Ce) crystals codoped with various concentrations of Ca (0, 0.1, 0.2, 0.3, and 0.4 at% in the melt) are presented. The scintillation and optical properties including photoluminescence decay, emission, excitation, absorption, afterglow and thermoluminescence properties are investigated as a function of Ca concentration. Experimental data show Ca codoping significantly reduces the trapped charge population in the crystal matrix. Hence, the scintillation decay time of LSO:Ce is shortened and the afterglow is suppressed. Thermoluminescence studies show a strong correlation between the integrated thermoluminescence intensity and the Ca concentration.

  • 96.
    Yuan, Weiming
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Szabó, Kálmán J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Rhodium-Catalyzed Geminal Oxyfluorination and Oxytrifluoro-Methylation of Diazocarbonyl Compounds2016Inngår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 55, nr 29, s. 8410-8415Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new reaction for the rhodium-catalyzed geminal-difunctionalization-based fluorination is presented. The substrates are aromatic and aliphatic diazocarbonyl compounds. As the fluorine source a stable and easily accessible benziodoxole reagent was used. A variety of alcohol, phenol, and carboxylic acid reagents were employed to introduce the second functionality. The reaction was extended to trifluoromethylation using a benziodoxolon reagent. The fluorination and trifluoromethylation reactions probably proceed by a rhodium-containing onium ylide type intermediate, which is trapped by either the F or CF3 electrophiles.

  • 97.
    Zani, Lorenzo
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    Adolfsson, Hans
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Synthesis of novel amino-acid-derived sulfinamides and their evaluation as ligands for the enantioselective transfer hydrogenation of ketones2008Inngår i: European Journal of Organic Chemistry, ISSN 1434-193X, nr 27, s. 4655-4664Artikkel i tidsskrift (Fagfellevurdert)
  • 98.
    Zhao, Gui-Ling
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Dziedzic, Pawel
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Ullah, Farman
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi, Avdelningen för strukturkemi.
    Córdova, Armando
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Organocatalytic enantioselective domino synthesis of highly functionalized cyclohexanes with an all-carbon quaternary stereocenter2009Inngår i: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 50, nr 26, s. 3458-3462Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A highly enantioselective organocatalytic domino Michael/aldol reaction is presented. The reaction is catalyzed by chiral amines and gives access to highly functionalized cyclohexanes with one all-carbon quaternary stereocenter and multiple chiral stereocenters in high yields and 83–98% ee.

  • 99.
    Zhao, Gui-Ling
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Rios, Ramón
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Vesely, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Córdova, Armando
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Organocatalytic enantioselective aminosylfenylation of alpha,beta-unsaturated aldehydes2008Inngår i: Angewandte Chemie International Edition, ISSN 1433-7851, Vol. 47, nr 44, s. 8468-8472Artikkel i tidsskrift (Fagfellevurdert)
  • 100.
    Zhao, Jian
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Jonker, Sybrand J. T.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Meyer, Denise N.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Schulz, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Tran, C. Duc
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Eriksson, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Szabó, Kálmán J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Copper-catalyzed synthesis of allenylboronic acids. Access to sterically encumbered homopropargylic alcohols and amines by propargylboration2018Inngår i: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 9, nr 13, s. 3305-3312Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Tri- and tetrasubstituted allenylboronic acids were prepared via a new versatile copper-catalyzed methodology. The densely functionalized allenylboronic acids readily undergo propargylboration reactions with ketones and imines without any additives. Catalytic asymmetric propargylborylation of ketones is demonstrated with high stereoselectivity allowing for the synthesis of highly enantioenriched tertiary homopropargyl alcohols. The reaction is suitable for kinetic resolution of racemic allenylboronic acids affording alkynes with adjacent quaternary stereocenters.

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