Activation of H2 with Manganese(I)-Phosphido Complexes

Metal-ligand cooperativity (MLC) predominantly occurs across transition-metal amido moieties. In contrast, there are few reports of activation of H2 or substrate across metal–phosphido linkages, and all of the first-row metal examples use N-heterocyclic phosphido donors. In this report, we highlight a discovery of the first MLC dihydrogen activation with first-row transition metal M-PR2 (R = alkyl or aryl) complexes using dinuclear Mn(I)-bisphosphido complexes. In addition, we demonstrate that oxidative addition of P–Cl bond leads to the same Mn(I)-bisphosphido complexes at elevated temperatures, enabling a simple and versatile strategy for in-situ reduction of phosphine chlorides to phosphine using dihydrogen, a process that appears general having success with both diaryl- and dialkyl-phosphines.