Metal-free regioselective hydrobromination of alkynes through CH/CBr activation

Abstract A metal-free regioselective hydrobromination of alkynes has been developed to provide the Markovnikov-type vinyl bromides in good yields using dibromomethane/N,N-dimethylaniline as in-situ ‘HBr’ source. This protocol also represents an elegant example of the activation of sp2 C H and C Br bonds in one pot, in which ‘HBr’ is generated and transferred under mild metal-free conditions. D-incorporated experiments were employed to investigate the reaction mechanism and a plausible reaction path was proposed.