Two dimensional inorganic electride-promoted electron transfer efficiency in transfer hydrogenation of alkynes and alkenes

Abstract

A simple and highly efficient transfer hydrogenation of alkynes and alkenes by using a two-dimensional electride, dicalcium nitride ([Ca<inf>2</inf>N]+·e-), as an electron transfer agent is disclosed. Excellent yields in the transformation are attributed to the remarkable electron transfer efficiency in the electride-mediated reactions. It is clarified that an effective discharge of electrons from the [Ca<inf>2</inf>N]+·e- electride in alcoholic solvents is achieved by the decomposition of the electride via alcoholysis and the generation of ammonia and Ca(OiPr)<inf>2</inf>. We found that the choice of solvent was crucial for enhancing the electron transfer efficiency, and a maximum efficiency of 80% was achieved by using a DMF mixed isopropanol co-solvent system. This is the highest value reported to date among single electron transfer agents in the reduction of C-C multiple bonds. The observed reactivity and efficiency establish that electrides with a high density of anionic electrons can readily participate in the reduction of organic functional groups. © 2015 The Royal Society of Chemistry.