Allyl- and allenylboronic acids are valuable reagents in organic synthesis due to their configurational stability and high reactivity. Few allyl- and allenylboronates are commercially available. Therefore, both the preparation and synthetic application of these organoboronic acids are subjects of study. A copper-catalyzed method for the synthesis of tetrasubstituted allenylboronic acids is presented in this thesis. Several enantioselective applications of these allenylboronic acids are presented, including the synthesis of chiral α-amino acid derivatives. Applications of γ,γ-disubstituted allylboronic acids in asymmetric organocatalysis are also presented in this thesis. Varying the E-Z geometry of the allylboron reagents allowed for stereodivergent synthesis of products bearing up to three stereocenters. A common element in the asymmetric methodologies described in this thesis is the application of BINOL-type organocatalysts. The most notable example is the methodology developed for the preparation of α-chiral allylboronic acids via asymmetric homologation of olefinic boronic acids. The resulting chiral boronic acids are of high synthetic interest, which is demonstrated by the wide variety of synthetic applications including allylboration, oxidation, and a purification sequence leading to isolated α-chiral allylboronic acids.

This thesis describes the development of a novel organocatalytic method for the synthesis of chiral allyl- and propargyl- organoboron compounds with high enantioselectivity. These organoboron species are versatile building blocks in asymmetric synthesis.

We have developed a new efficient homologation method of alkenyl boronic acids. This reaction affords enantiomerically enriched trifluoromethylated allylboronates. These organoboron species were used in allylboration of carbonyl compounds, imines and indole derivatives. The reactions proceeded with a remarkably high stereoselectivity to give homoallylic alcohols and amines. In addition, the chiral allylboronic acids can be oxidized to the corresponding alcohols with retention of the configuration.

Based on the homologation of alkenylboronic acids a new three-component reaction is developed. This reaction involved coupling of alkynyl boronates, diazo compounds and ketones in the presence of chiral organocatalysts. This coupling proceeds with high selectivity under mild reaction conditions. The three-component coupling reaction is based on a homologation–allylboration sequence. The process is suitable for synthesis of CF₃- and TMS-substituted allenols with excellent diastereo- and enantioselectivity. Application of aromatic, cyclic and non-cyclic ketones leads to formation of chiral tertiary allenols.

We have also studied the effects of boronic acid esters on the outcome of the homologation reaction. It was found that a facile transesterification of the boronate precursors with the organocatalyst, BINOL derivatives, is a prerequisite of the successful homologation reaction.

Organoboron reagents, such as allyl- and alkylboronic acids, have indisputable value in the applications of synthetic chemistry. The studies presented in this thesis focus on 1,1′-Bi-2-naphthol (BINOL)-catalyzed asymmetric homologation of the boronic acids by trifluoromethylated diazoalkanes to obtain allyl- and alkylboronic acids. 

First, BINOL was used as the organocatalyst for the homologation of vinylboroxines. This novel methodology allowed us to obtain in situ generated chiral allylboronic acids, which were protected by diamino naphthalene (DanH). Then the BDan derivatives were purified by chromatography, and subsequently hydrolyzed to allylboronic acids. In situ generated boronates underwent a one-pot allylboration reaction as well as oxidation to give homoallyl alcohols and α-CF₃-substituted secondary alcohols. 

Next, a method for asymmetric homologation of alkyl- and arylboronic esters was also developed using (R)-iodo-BINOL catalyst and diazoalkane reagents. The method allowed to access in situ generated trifluoromethylated boronic esters which later were derivatized to BDan analogues or converted to alcohols as well as deborylated carboxylates with high enantiopurities. 

Finally, the applicability of the enantioenriched α-CF₃-substituted allylboronic acids was investigated in Cu-catalyzed cross-coupling with α-diazoketones. This method is suitable for the synthesis of alkenyl-trifluoromethyl-substituted alkyl ketones with high selectivity. Using this procedure, the β-fluoride and β-hydride eliminations could be avoided, allowing stereocontrolled construction of new C(sp³)–C(sp³) bonds.