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: 20; Issue: 2 Linguagem: Inglês
10.1016/0304-5102(83)83008-9
ISSN1873-3131
AutoresDaniel Beaupère, Louis Nadjo, R. Uzan, P. Bauer,
Tópico(s)Chemical Synthesis and Analysis
Resumo1H NMR spectroscopy and isotope effects have been used to elucidate some new details in the mechanism of the transfer hydrogenation of α,β-unsaturated ketones by alcohols in the presence of catalytic amounts of RhH(PPh3)4. The isotopic labelling of the alcohols shows the regioselectivity of the hydrogen transfer to olefinic ketones. For the first time, to our knowledge, the cleavage of an O-H bond has been shown to be the rate-limiting step in the aforementioned reaction. A general mechanistic scheme is postulated which is supported by various experimental data using several techniques.
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