Asymmetric double-conjugate addition of alkenylboronic acids to dienones catalyzed by chiral diols†
Abstract
Asymmetric conjugate addition of organic boronic acids to dienones was successfully achieved by using chiral 3,3′-disubstituted-BINOLs or hydroxytetraphenylenes as the catalyst. A series of enantiopure bis-adducts were readily generated in high yields (up to 99%) with excellent chemoselectivities, diasteroselectivities (up to 98 : 2 dl/meso), and enantioselectivities (up to >99% ee). These catalytic systems exhibited elements of high efficiency and broad substrate scope.