The mechanism of disproportionation of D-glucose catalysed by hydridochlorocarbonyltris(triphenyl-phosphine)ruthenium(II) in tetrahydrofurfuryl alcohol

Abstract

The disproportionation of D-glucose in tetrahydrofurfuryl alcohol (THFA) catalysed by RuHCl(CO)(PPh3)3is suggested to proceed by hydride transfer from a dissociated catalyst species to the coordinated aldehyde form of glucose. Subsequent steps involve the coordination of the pyranose form of glucose, formation of the metal alkoxide, release of D-glucitol and hydrogen transfer from alkoxide to the metal. The kinetic data are compatible with the rate expression, RATE = (kK[G][Ru]0)/([P] + K), where k, K, [G], [Ru]0 and [P] represent the rate constant of the rate-determining step, the equilibrium constant for the dissociation of the catalyst, concentrations of glucose, catalyst and added triphenylphosphine respectively.