Chemoselective Esterification and Amidation of Carboxylic Acids with Imidazole Carbamates and Ureas
摘要:
Imidazole carbamates and ureas were found to be chemoselective esterification and amidation reagents. A wide variety of carboxylic acids were converted to their ester or amide analogues by a simple synthetic procedure in high yields
On the reactivity of imidazole carbamates and ureas and their use as esterification and amidation reagents
作者:Stephen T. Heller、Richmond Sarpong
DOI:10.1016/j.tet.2011.09.057
日期:2011.11
The optimization, substrate scope, and mechanism of esterification and amidation of carboxylic acids mediated by imidazole-based reagents are discussed. The innate reactivity of carbonylimidazole reagents with a range of nucleophiles is also explored. New reagents developed for the synthesis of alpha,beta-unsaturated esters are described, as are reagents for the preparation of tertiary amides directly from carboxylic acids. (C) 2011 Elsevier Ltd. All rights reserved.