Electroreductive Divergent Hydrogenations of Alkynes to Alkenes or Alkanes

An electrochemical platform enabling condition-dependent chemoselective reduction of alkynes was developed. Modulation of electrochemical parameters allowed selective formation of alkenes or alkanes via proton transfer or nickel hydride formation pathways, as supported by potentiodynamic analyses and detailed isotope-labeling studies. The reactions proceed under mild conditions without the use of molecular hydrogen, featuring broad scope and high functional-group tolerance, thus providing a practical and sustainable approach to chemoselective alkyne reduction.