Palladium Catalyzed Asymmetric Three-Component Coupling of Boronic Esters, Indoles, and Allylic Acetates

Boronic esters react with 2-lithiated indoles to form boronate intermediates. The boronate reacts with allylic acetates in the presence of (BINAP)Pd catalysts to allylate C3 concurrent with alkyl migration from B to C2 of the indole. Overall, the process is a three-component coupling that joins an allylic acetate, and indole and an organo-B­(pin) species to provide substituted indoles and indolines with high enantio-, regio-, and diastereoselectivity.