Chiral N,N'-dioxide-Ytterbium(III) complexes promoted the asymmetric addition of diethyl phosphate to aldehydes, giving the corresponding products with good yields and enantioselectivities. The addition of pyridine favored both reactivity and enantioselectivity. A possible catalytic cycle was proposed to explain the mechanism of the asymmetric hydrophosphonylation of aldehydes. (C) 2010 Elsevier Ltd. All rights reserved.
Manganese-proline derived new catalyst system for the enantioselective synthesis of α -hydroxyphosphonates and α -aminophosphonates
A novel manganese/proline-derived catalyst system is reported for the stereoselective synthesis of α-hydroxyphosphonates and α-aminophosphonates. The reaction proceeded smoothly under mild reaction conditions with efficient reaction times. The resulting products were obtained with high yields and good enantioselectivities (up to 83% ee).