MOP-type binaphthyl phosphite and diamidophosphite ligands and their application in catalytic asymmetric transformations

Abstract

Monodentate phosphite and diamidophosphite ligands have been developed based on O-methyl-BINOL. These chiral ligands are easy to prepare from readily accessible phosphorylating reagents - (Sa or Ra)-2- chlorodinaphtho[2,1-d:1′,2′-f]-[1,3,2]dioxaphosphepine and (2R,5S)-2-chloro-3-phenyl-1,3-diaza-2-phosphabicyclo[3.3.0]octane. The new ligands have demonstrated excellent enantioselectivity in the palladium-catalysed allylic substitution reactions of (E)-1,3-diphenylallyl acetate with sodium p-toluenesulfinate (up to 99% ee), pyrrolidine (up to 97% ee), dipropylamine (up to 95% ee) and dimethyl malonate (up to 99% ee). In the palladium-catalysed deracemization of ethyl (E)-1,3-diphenylallyl carbonate, up to 96% enantioselectivity has been achieved. The diamidophosphite ligands have exhibited very good enantioselectivity in the Rh-catalysed asymmetric hydrogenation of dimethyl itaconate (up to 90% ee). © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.