Stereocontrolled Creation of Adjacent Quaternary and Tertiary Stereocenters by a Catalytic Conjugate Addition

摘要

Adjacent quaternary and tertiary stereocenters as in structure 1 are common structural motifs in complex natural products.In principle,the stereocontrolled conjugate addition of a prochiral trisubstituted carbon nucleophile to a prochiral beta-substituted Michael acceptor with a chiral catalyst could provide a one-step construction of such highly congested motifs from simple precursors [Eq.(1)].However,this requires the catalyst to impart both high enantioselectivity and diastereoselectivity in a sterically demanding,intermo-lecular C-C bond formation that simultaneously creates both the quaternary and tertiary stereocenters.