Palladium-catalyzed sequential arylation and allylic alkylation of highly functionalized ketones: a concise synthesis of mesembrine.

An unprecedented palladium-catalyzed sequential procedure toward arylation and allylic alkylation of highly functionalized cyclohexenones was developed. This new protocol leads to useful building blocks containing a benzylic quaternary carbon in only one step. A concise total synthesis of mesembrine based on this procedure was achieved in only five steps with 22% overall yield.