Mechanistic insight into the cleavage and coupling of CO with molybdenum complexes: Toward upgrading oxygenated C1 precursors

CO reductive coupling chem. has been demonstrated with Mo complexes supported by multidentate terphenyl diphosphine ligands. Low temp. synthetic, kinetics, and isotopic labeling studies have been performed to gain mechanistic insight into CO activation chem. Four- and two-electron coupling chem. to C_2 species as well as further CO enchainment to C_3 species were obsd. Deoxygenation chem. occurs via a terminal Mocarbide species which acts as a precursor to C-C coupling chem. with CO. The redox non-innocent and labile pendant arene donor is instrumental for the obsd. reactivity