Nickel-catalyzed asymmetric transfer hydrogenation

Abstract

This thesis describes my work on nickel-catalyzed asymmetric transfer hydrogenation of unsaturated C=C and C=N bonds using various hydride sources.It contains three main parts.Chapter one reported a highly enantioselective asymmetric transfer hydrogenation of -unsaturated esters with a chiral phosphine ligand, (R)-Me-DuPhos.With formic acid and triethyl amine worked as hydride source, excellent conversion and enantioselectivity were obtained.Furthermore, deuterium labeling experiments revealed a possible mechanism.I also reported asymmetric transfer hydrogenation of -unsaturated esters with DMF and water as hydride source.Chapter two described asymmetric transfer hydrogenation of cinnamates, betadehydroacetamidoesters and hydrazones with acetic acid and indium powder.With nickel/(S)-Binapine or (R)-Me-DuPhos catalytic system, a series of C=C and C=N gave high enantioselectivities.Chapter three reported asymmetric deuteration of -unsaturated esters with deuterium water and indium powder as hydride source.For all the substrates tested, excellent conversion, enantioselectivity and deuterium ratio were obtained.This work provided a novel methodology for the synthesis of chiral deuterated products without expensive and explosive deuterium gas.