Gold(I)/Chiral Rh(III) Lewis Acid Relay Catalysis Enables Asymmetric Synthesis of Spiroketals and Spiroaminals

摘要

An efficient asymmetric cascade reaction of keto esters with alkynyl alcohols and amides was catalyzed by the combination of achiral gold(I) catalysis and chiral Rh(III) Lewis acid catalysis as asymmetric relay catalysis. The corresponding spiroketals and spiroaminals were synthesized in good yields (up to 99%), with good diastereoselectivity (up to 20:1 dr) and excellent enantioselectivity (up to 98% ee).