Copper-catalyzed Cross-coupling Reactions of Epoxides with gem-Diborylmethane

Xiao and Fu et al. have reported the copper-catalyzed cross-coupling reactions of epoxides with gem-diborylmethane. According to their results, epoxides react with bis[(pinacolato)boryl]methane in the presence of CuI and a base of lithium tert-butoxide giving the desired γ-hydroxyl boronic esters in high yields. In this reaction, the formed boronic esters are important synthetic intermediates in C—C bond-forming reactions. In addition, this synthetic approach also can be applicable to other reactants such as chiral epoxides and aziridines, wherein the corresponding chiral γ-hydroxyl boronic esters and γ-amino boronic esters are obtained, respectively.