Construction of Vicinal Quaternary Centers via Iridium-Catalyzed Asymmetric Allenylic Alkylation of Racemic Tertiary Alcohols

Abstract

. This robust catalytic system effects highly enantioconvergent and regioselective alkylation of racemic tertiary α-allenyl alcohols with tetrasubstituted silyl ketene acetals. The transformation displays broad functional group tolerance for both reaction components and allows efficient generation of β-allenyl ester products in good yield and with excellent enantioselectivity. Furthermore, both the allene and ester functionalities were leveraged to upgrade the structural complexity of the products via a series of stereoselective metal-catalyzed functionalization reactions.