One-step synthesis of 1-halo-1,3-butadienes via ruthenium-catalysed hydrohalogenative dimerisation of alkynes

An efficient, novel and direct access to 1-halo-1,3-butadienes is developed. This stereoselective ruthenium-catalysed reaction proceeds under mild conditions via the head-to-head oxidative coupling of two alkynes and a concomitant hydrohalogenation.