[3+2] Cycloaddition of Propargylamines and α-Acylketene Dithioacetals: A Synthetic Strategy for Highly Substituted Pyrroles
作者:Yu-Long Zhao、Chong-Hui Di、Si-Di Liu、Jia Meng、Qun Liu
DOI:10.1002/adsc.201200375
日期:2012.12.14
A new [3+2] cycloaddition strategy for the direct synthesis of highlysubstituted pyrroles from the readily available α-acylketene dithioacetals (or related substrates) and commercially available propargylamines under mild metal-free conditions has been developed. In this reaction, the acyl group plays a critical role in driving the conjugate addition of propargylamine and further cyclization to give
A series of 2,3,4-trisubstituted and 1,2,3,4-tetrasubstituted pyrroles were synthesized via [3+2] cycloaddition of alpha-acyl ketene dithioacetals (or related substrates) with commercially available propargylamines as 1,3-dipoles in water. Most of the reactions can be performed in the absence of an external base. The reaction of secondary amine (N-methylprop-2-yn-1-amine) with alpha-acyl ketene dithioacetals showed different reaction behaviours depending on the addition or absence of an external base. (C) 2013 Elsevier Ltd. All rights reserved.