achiral electron-rich mono-phosphine ligand, catalyzes efficient asymmetric hydrogenation of a wide range of aryl ketones, affording chiral alcohols with high yields and moderate to excellent enantioselectivities (29 examples, up to 93% ee). Notably, the achiral mono-phosphine ligand shows a remarkable effect on the enantioselectivity of the reaction.
Several 5,16-dialkyl(diaryl)-5,16-dihydro-5,16-diphospha-tetraepoxy[22]annulenes(2.1.2.1) 9 as possible precursors of aromatic 5,16-diphospha-tetraepoxy[22]annulenes(2.1.2.1) 8 are synthesized by cyclizing Wittig-reactions of the phosphane dialdehydes 15 with the bis-ylids of the phosphane-bisphosphoniumsalts 19.