E- and Z-Stereoselectivity in the preparation of enamides from glycidyl sulfonamides and carbamates
作者:Jack A. Brown、Vijay Chudasama、Melvyn E. Giles、Duncan M. Gill、Philip S. Keegan、William J. Kerr、Rachel H. Munday、Karen Griffin、Andrew Watts
DOI:10.1039/c1ob06569f
日期:——
Treatment of glycidyl sulfonamides with LDA delivers the corresponding enesulfonamide with good selectivity for the E-isomer, whereas the corresponding carbamates exhibit selectivity for the Z-enecarbamate. An E1cB elimination mechanism proceeding from a substrate–base chelate complex is advanced as rationalisation of the latter set of Z-selective outcomes.
用LDA处理缩水甘油基磺酰胺可得到对E-异构体具有良好选择性的相应的烯磺酰胺,而相应的氨基甲酸酯对Z-烯氨基甲酸酯则具有选择性。随着对Z选择性结果的合理化,从底物-基螯合物开始的E1cB消除机制得到了发展。