Synthesis of Optically Active Boron-Silicon Bifunctional Cyclopropane Derivatives through Enantioselective Copper(I)-Catalyzed Reaction of Allylic Carbonates with a Diboron Derivative

摘要

Chirally substituted cyclopropane frameworks are widely found in naturally occurring organic compounds and pharmaceuticals. Their stereoselective and efficient synthesis is hence an important issue in organic synthesis. Herein we report a highly diastereo- and enantioselective copper(I)-catalyzed reaction that converts γ-silylated allylic carbonates (1) and a diboron species (2) into previously unreported, optically active B,Si bifunctional cyclopropane derivatives (B = (pin)B; Si = Me3Si 3 a, PhMe2Si 3 b, BnMe2Si 3 c, Scheme 1). B,Si bifunctional cyclopropane (1S,2S)-3c was derivatized into (1S,2R)-2-phenyl-1-cyclopropanol by Suzuki-Miyaura coupling and Tamao oxidation.