Journal of the American Chemical Society, Vol.142, No.23, 10244-10249, 2020
Chiral Metallacycles as Catalysts for Asymmetric Conjugate Addition of Styrylboronic Acids to alpha,beta-Enones
Introducing self-assembly strategies into the construction of catalysts has been proven to have great advantages in asymmetric catalysis. We constructed two chiral metalla-triangles by highly efficient coordination-driven self-assembly from a chiral 3,3'-dipyridyl-substituted BINOL donor. They were successfully applied in asymmetric conjugate addition of a series of alpha,beta-unsaturated ketones with trans-styrylboronic acids. The use of these metalla-triangles as supramolecular catalysts is obviously conducive to the enhancement of catalytic activity and stereoselectivity in the presented addition reactions. Under induction of the chiral metalla-triangles, an array of alpha,beta-enones were converted to chiral gamma,delta-unsaturated ketones in medium to quantitative yields (40-98%) with high enantioselectivities (87-96% ee).