Rhodium(I) hydrogenation in water: Kinetic studies and the detection of an intermediate using 13C{1H} PHIP NMR spectroscopy

The mechanism for hydrogenation of dimethylmaleate in water using cationic rhodium complexes with water-soluble bi-dentate phosphines has been investigated using kinetics and a novel method for the indirect detection of intermediates in catalytic hydrogenation reactions, whereby a late intermediate was detected. A mechanism is proposed involving fast, irreversible substrate binding followed by a rate-determining reaction with dihydrogen.