The use of new carboranylphosphite ligands in the asymmetric Rh-catalyzed hydrogenation

A series of new monodentate phosphite ligands based on carboranes have been synthesized and used for asymmetric Rh-catalyzed hydrogenation of prochiral olefins in CH(2)Cl(2) with the result of up to 99.5% ee. High reactivities (100% conversion in 45-60 min) and enantioselectivities (up to 92%) were obtained in the hydrogenation of dimethyl itaconate in supercritical CO(2), In this case the catalytic performance is affected greatly by hydrogen and total pressures. (C) 2009 Elsevier B.V. All rights reserved.