Selectivity in the acid catalysed reduction of carbonyl compounds to alcohols by bis(triphenylphosphine)copper(I) tetrahydroborate: Reduction of aldehydes in the presence of ketones

✍ Scribed by G.W.J. Fleet; P.J.C. Harding

• Publisher: Elsevier Science
• Year: 1981
• Tongue: French
• Weight: 240 KB
• Volume: 22
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)92520-1

✦ Synopsis

Bis(triphenylphosphine)copper(I) tetrahydroborate reduces carbonyl compounds to alcohols in the presence of acid catalysts in excellent yields with high stereoselectivity; a.B-unsaturated aldehydes are reduced regioselectively. In a mixture of an aldehyde and a ketone, an aldehyde may be reduced preferentially. There is continuing interest in functional group' and stereo-2-4 selectivity in the reduction of carbonyl compounds by complex hydrides. The size of complex transition metal borohydrides. together with their solubility in non-hydroxylic organic solvents. make them ideal candidates for studies of selective reduction. Accounts of the stoichiometric reduction of carbonyl groups by u-bis(cyanotrihydroborato)tetrakis-(triphenylphosphine) dicopper(1) under acid conditions' and bisCcyclopentadienyl)chloro-tetrahydroboratozirconiumCIV1 under neutral conditions6 have prompted us to report our work on the acid catalysed reactions of bis(triphenylphosphine)copperCI) tetrahydroborate; this reagent under neutral conditions has been shown to be effective