Pd-mBDPP-catalyzed regioselective internal arylation of electron-rich olefins by aryl halides

摘要

meso-2,4-Bis(diphenylphosphino) pentane (mBDPP) has proved to be an effective regiocontrolling ligand for palladium-catalyzed internal arylation by aryl bromides of electron-rich olefins in a common solvent DMSO with no need for any halide scavengers. The arylation of the benchmark electron-rich olefin butyl vinyl ether took place smoothly to afford exclusively alpha-arylated product with high isolated yields. The better performance of mBDPP, compared with that of the commonly used DPPP [1,3-bis(diphenylphosphino) propane], highlights the important but subtle effect of ligand on the regioselectivity of the Heck arylation reactions.