Copper-Catalyzed Cyanomethylation of Allylic Alcohols with Concomitant 1,2-Aryl Migration: Efficient Synthesis of Functionalized Ketones Containing an α-Quaternary Center
A copper-catalyzed alkylation of allylic alcohols by alkyl nitriles with concomitant 1,2-aryl migration was developed. Formation of the alkyl nitrile radical was followed by its intermolecular addition to alkenes and the migration of a vicinal aryl group with the concomitant generation of a carbonyl functionality to complete the domino sequence. Mechanistic studies suggested that 1,2-aryl migration proceeded through a radical pathway (neophyl rearrangement). The protocol provided an efficient route to functionalized ketones containing an a-quaternary center.