Stereoselectivity in hydrosilylative reduction of substituted cyclohexanone derivatives with chiral rhodium-bis(oxazolinyl)pyridine catalyst

Article abstract of DOI:10.1016/S0957-4166(00)86036-X

Stereoselectivity in the reduction of substituted cyclohexanones, 4-tert-butylcyclohexanone, 2-methylcyclohexanone, 2-phenylcyclohexanone, and 2-methoxycarbonyl-methylcyclohexanone, was examined with chiral rhodium-bis(oxazolinyl)pyridine catalyst and diphenylsilane. 4-tert-Butylcyclohexanone gave the corresponding trans(equatorial)-alcohol predominantly; the ratio of the trans/cis alcohols, 67:33. Other 2-substituted cyclohexanones showed exclusive enantioselectivities for each diastereomer in terms of the kinetic resolution; e.g. from 2-phenylcyclohexanone, 99% ee of (1S,2R)-trans-2-phenylcyclohexanol and 96% ee of (1S,2S)-cis-2-phenylcyclohexanol in 92% yield (the trans/cis ratio = 51:49).