Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan, Hubei 430079, China.
J Org Chem. 2011 Jan 7;76(1):281-4. doi: 10.1021/jo101699r. Epub 2010 Dec 8.
A novel organocatalytic asymmetric cyclopropanation of β,γ-unsaturated α-ketoesters with stabilized sulfur ylides using C(2)-symmetric urea as a hydrogen-bond catalyst has been described. This reaction allows an efficient access to 1,2,3-trisubstituted cyclopropane derivatives in moderate to good yields with up to 16:1 dr and 90:10 er under mild reaction conditions. The mechanism study proved that the high stereoinduction originated from the cooperative effect of the hydrogen-bond catalyst.
一种新型的手性有机催化β,γ-不饱和α-酮酯与稳定的硫叶立德的不对称环丙烷化反应已被描述。该反应使用 C(2)-对称脲作为氢键催化剂，在温和的反应条件下，以中等至良好的收率，高达 16:1 的 dr 和 90:10 的 er，高效地得到了 1,2,3-三取代的环丙烷衍生物。机理研究证明，高立体诱导源于氢键催化剂的协同效应。
