An efficient chemoselective strategy for the preparation of (E)-cinnamic esters from cinnamaldehydes using heterogeneous catalyst and DDQ
作者:Arun K. Sinha、Anuj Sharma、Anand Swaroop、Vinod Kumar
DOI:10.1016/j.tet.2006.11.011
日期:2007.1
An efficient chemoselective protocol is developed for the synthesis of (E)-cinnamic esters from substituted cinnamaldehydes or cinnamyl alcohols using a combination of DDQ and heterogeneous catalyst under microwave irradiation. The method showed remarkable selectivity for cinnamaldehydes over aliphatic and aromatic aldehydes, which is a novel finding. The results demonstrate that the developed protocol can be a useful synthetic tool for chemoselective esterification in total synthesis of complex organic compounds. (c) 2006 Elsevier Ltd. All rights reserved.
The Intramolecular, Stereoselective Addition of Sulfoximine Carbanions to α,β-Unsaturated Esters
作者:Michael Harmata、Xuechuan Hong
DOI:10.1021/ja034744z
日期:2003.5.1
ortho-Bromocinnamates can be coupled with methyl phenylsulfoximine to afford N-arylsulfoximines in excellent yield. Treatment of these products with an amide base results in a completely stereoselective cyclization to afford enantiomerically pure benzothiazines. This reaction is stereospecific.