New aspects of the transfer hydrogenation of α,β-unsaturated ketones by alcohols in the presence of hydridotetrakis(triphenylphosphine)-rhodium(I)
1983; Science Press; Volume: 18; Issue: 1 Linguagem: Inglês
10.1016/0304-5102(83)80071-6
ISSN1873-3131
AutoresDaniel Beaupère, Louis Nadjo, R. Uzan, P. Bauer,
Tópico(s)Chemical Reactions and Isotopes
ResumoA large variety of alcohols and α,β-unsaturated ketones has been used to demonstrate the scope and synthetic application of the transfer hydrogenation reaction with RhH(PPh3)4 as a catalyst. The reaction is shown to proceed under mild conditions with favorable kinetics. A hitherto unobserved influence of the mixing order of reactants and catalyst has been found and explained. Direct evidence has also been gained for complex formation between the donors and catalyst, and its equilibrium constant measured. The influence of the concentrations and the structures of the donors and acceptors has been studied in detail. It turns out that the steric effect is the predominant factor. In conclusion, details concerning the nature and structures of some reaction intermediates have been gained and serve as a basis for a first rough description of the general pathways of the transfer hydrogenation reaction mechanism.
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