Chiral phosphites derived from carboranes: electronic effect in catalytic asymmetric hydrogenation

Lyubimov S.E., Kalinin V.N., Tyutyunov A.A., Olshevskaya V.A., Dutikova Y.V., Petrovskii P.V., Safronov A.S., Davankov V.A., Cheong C.S.

A series of new fine-tunable monodentate phosphite and phosphoramidite ligands based on carboranes have been synthesized and used for asymmetric Rh-catalyzed hydrogenation of prochiral olefins with the result of up to 99.8% ee. Dependence of the enantioselectivity on the electron-withdrawing or electron-donating properties of the carboranyl substituent has been studied.