Copper and Palladium-Mediated Transformationsof Allylic and Propargylic Substrates
2014 (English)Licentiate thesis, monograph (Other academic)
This thesis is focused on the development of new palladium and copper-mediated reactions for functionalization of alkenes and propargylic alcohol derivatives. We have developed an efficient procedure for the synthesis of allenyl and propargyl boronate from propargylic carbonates and acetates. The reactions were performed under mild conditions for the synthesis of a variety of allenyl boronates. We have also observed a switch of regioselectivity for the formation of propargylic boronates using CuCl as a co-catalyst. This is, as far as we know, the first metal-catalyzed reaction for the synthesis of propargylic boronates. Furthermore, the synthesis of 1,2-diborylated butadienes was achieved with high diastereoselectivity from propargylic epoxides. A wide variety of propargylic epoxides could be converted to the corresponding dienes and this is the first catalytic protocol to form 1,2-diborylated butadienes.
We have also studied the copper-mediated trifluoromethylation of propargylic halides and trifluoroacetates. Depending on the temperature, two different regioselective outcomes were observed. It was also shown that a transfer of chirality occurred when an enantioenriched starting material was used.
In the last part of the thesis, we have described a method for palladium-catalyzed functionalization of allylic C-H bonds for selective synthesis of allylic silanes. The reaction is regioselective and gives only the linear allylic silane. The protocol only works under highly oxidative conditions which suggest a mechanism involving high oxidation state palladium intermediates.
Place, publisher, year, edition, pages
Stockholm University, 2014. , 37 p.
IdentifiersURN: urn:nbn:se:su:diva-102826OAI: oai:DiVA.org:su-102826DiVA: diva2:713306
2014-05-12, Room A501/A507, Svante Arrhenius väg 16C, Stockholm, 14:00