Elucidation of the resting state of a rhodium NNN-pincer hydrogenation catalyst that features a remarkably upfield hydride 1H NMR chemical shift

Abstract

Rhodium(I) alkene complexes of an NNN-pincer ligand catalyze the hydrogenation of alkenes, including ethylene. The terminal or resting state of the catalyst, which exhibits an unprecedentedly upfield Rh–hydride ¹H NMR chemical shift, has been isolated and a synthetic cycle for regenerating the catalytically active species has been established.