Organocatalytic Asymmetric Vinylogous Aldol Reaction of Allyl Aryl Ketones to Silyl Glyoxylates.

A direct organocatalytic asymmetric vinylogous aldol reaction of allyl aryl ketones to silyl glyoxylates has been developed through the bifunctional catalyst, giving the α-hydroxysilanes with excellent enantioselectivity (up to 95% ee) and in high yields (up to 96%). The success of this catalytic methodology offers an opportunity to tackle the problems in the nucleophilic addition to acylsilanes. To activate both allyl aryl ketones and acylsilanes, the utilized bifunctional catalyst was an ideal organocatalyst in this unprecedented transformation.