Selective reduction of alkynes by the reagent Sml2 - Transition metal catalysts - proton donors

Abstract Alkynes were selectively reduced to cis-olefins under mild conditions by Sml 2 in admixture with first-row transition metal catalysts and appropriate proton donors, in which the corresponding transition metal hydrides are presumed as the reactive species. The conditions also effected the conversion of 1,6-diynes to the corresponding five-membered carbocycles.