Rhodium(I) hydrogenation in water:: Kinetic studies and the detection of an intermediate using 13C{1H} PHIPNMR 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. (c) 2006 Elsevier B.V. All rights reserved.