Suppressed beta-hydride elimination in palladium-catalyzed cascade cyclization-coupling reactions: An efficient synthesis of 3-arylmethylpyrrolidines

A novel type of palladium-catalyzed cascade cyclization-coupling reaction t hat proceeds with suppressed beta-hydride elimination has been found. One o f the N-sulfonyl oxygens is suggested to coordinatively stabilize an alkylp alladium intermediate, thus preventing the intermediate from the usual beta -elimination, This is the first sequential palladium-catalyzed coupling rea ction where the Suzuki and Heck reactions can compete. The reaction provide s an efficient synthetic route to 4-methylene-3-arylmethylpyrrolidines, whi ch are not readily available by other routes.