The chemistry of α-diazocarbonyl compounds has attracted great attention because of its extensive applications in organic chemistry since the first recorded synthesis of ethyl diazoacetate by Curtius in 1883. Recently, we developed highly enantioselective, catalytic cyclopropanation with diazoesters in the presence of chiral oxazaborolidinium ion in high yield (up to 93%) with high to excellent diastereoselectivity (up to 98% de) and enantioselectivity (up to 95% ee).
In this talk, we will present that highly enantioselective Carbon-Hydrogen and Carbon-Carbon insertion reactions with diazoesters. Theses methodologies were successfully applied to the synthesis of the natural products, sitophilate, and (+)-epijuvabione. As another application, optically active quaternary α- and β-amino esters were prepared from all carbon α-quaternary aldehydes in good yields and excellent enantioselectivities.