Unprecedented halide dependence on catalytic asymmetric hydrogenation of 2-aryl- and 2-alkyl-substituted quinolinium salts by using ir complexes with difluorphos and halide ligands
The first highly enantioselective hydrogenation of 2-arylquinolinium salts by using cationic dinuclear iridium (III) halide complexes with difluorphos and some atropisomeric chiral diphosphine ligands as catalyst precursors has been reported. Asymmetric h