Lewis Base Promoted Intramolecular Acylcyanation of α-Substituted Activated Alkenes: Construction of Ketones Bearing β-Quaternary Carbon Centers

A novel phosphine-promoted intramolecular acylcyanation of alpha-substituted activated alkenes has been developed, which provides a unique access to densely functionalized acyclic ketones bearing beta-quaternary carbon centers with a remarkable feature that both alpha- and beta-positions of activated alkene are functionalized.