Regio- and stereoselectivity in the concatenated enyne cross metathesis–metallotropic [1,3]-shift of terminal 1,3-diyne

Enyne cross metathesis of terminal 1,3-diynes with various alkenes afforded two products of distinctive connectivity, as the result of a uniform mode of initiation but different modes of termination events with or without metallotropic [1,3]-shift. Steric and electronic factors of the substituents on the 1,3-diynes play an important role in controlling the metallotropic [1,3]-shift of the propagating alkylidene intermediates and their regioselective trapping to the final products.