effective enantioselective hydrophosphonylation of aldehydes. A variety of aromatic, heteroaromatic, condensed-ring, α,β-unsaturated, and aliphatic aldehydes were found to be suitable substrates for the reaction, and the desired α-hydroxy phosphonate were obtained in good to excellent yields (up to 99%) with moderate to good enantioselectivities (up to 87% ee) under mild conditions (at 0 °C). A possible
Bis(oxazoline)-copper catalyzed enantioselective hydrophosphonylation of aldehydes
作者:Tao Deng、Chun Cai
DOI:10.1039/c4ra03269a
日期:——
A highly enantioselective copper-catalyzed hydrophosphonylation of aldehydes in the presence of bis(oxazoline) ligand is presented. The reaction proceeded smoothly under mild conditions. The resulting α-hydroxyphosphonates were obtained with high yields as well as enantioselectivities (up to 98% ee).
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).
transformations using chlorosilane reagents. The p-tolyl-substituted DIOPO (p-tolyl-DIOPO) was most effective for the reductive aldol reaction of chalcone and aldehydes with trichlorosilane, whereas the 2,8-dimethylphenoxaphosphine-derived DIOPO (DMPP-DIOPO) afforded the best enantioselectivity for the phosphonylation of conjugated aldehydes and the chlorinative aldol reaction of an ynone and benzaldehyde.
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.