Synthesis of chiral monodentate binaphthophosphepine ligands and their application in asymmetric hydrogenations

Abstract A general synthesis of chiral monodentate 4,5-dihydro-3 H -dinaphthophosphepines 4 and a detailed study of the catalytic performance of the resulting ligands 4a – n in benchmark hydrogenation reactions is presented. Hydrogenation of methyl α-acetamidocinnamate 11 and methyl α-acetamidoacrylate 13 proceeded with enantioselectivities up to 95% and 94%, respectively. The best enantioselectivity for the rhodium-catalyzed hydrogenation of dimethyl itaconate 15 was 88%.