Highly Enantioselective 1,4-Addition of Diethyl Phosphite to Enones Using a Dinuclear Zn Catalyst
作者:Depeng Zhao、Ye Yuan、Albert S. C. Chan、Rui Wang
DOI:10.1002/chem.200802688
日期:2009.3.9
Zinc benefits: The first catalytic asymmetric phospha‐Michael addition of enones has been developed. Under mild reaction conditions, the γ‐oxo phosphonates could be obtained in high yields (up to 99 %) with excellent enantioselectivities (93–99 % ee; see scheme). The strategy makes the asymmetric synthesis of biologically important phosphonate compounds more accessible.
Chiral ytterbium silylamide catalyzed enantioselective phospha-Michael addition of diethyl phosphite to chalcones
作者:Guoyao Li、Lu Wang、Zhigang Yao、Fan Xu
DOI:10.1016/j.tetasy.2014.06.008
日期:2014.7
An efficient and enantioselective phospha-Michael addition of diethyl phosphite to chalcones has been established. In the presence of a catalytic amount of chiral lanthanide silylamide generated from [(Me3Si)(2)N](3)Yb(mu-Cl)Li(THF)(3) and salen, the reaction produced the target gamma-oxophosphonates with high yields and enantioselectivity. (C) 2014 Elsevier Ltd. All rights reserved.