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.