Palladium-Catalyzed Direct a-Arylation of Methane Sulfonamides with Aryl Bromides

摘要

An effective palladium-catalyzed cross-coupling approach for the direct a-monoarylation of various methane sulfonamides using aryl bromides to access benzylic sulfonamides is presented. Electron-deficient, electron-rich, and heterocyclic aryl bromides were successfully cross-coupled, and sensitive functional groups were well tolerated. High reactivities and chemoselectivities were achieved using a combination of Pd(OAc)2 and Kwong's indole-based phosphine ligand. The application of the developed method to the synthesis of the biologically active 1-benzyl-4-(benzylsulfonyl)piperazine is also demonstrated.