Concise [4+3] cycloaddition reaction of pyrroles leading to tropinone derivatives
摘要:
A concise [4+3] cycloaddition reaction of pyrroles with 2-(silyloxy)allyl cations has been developed. The oxyallyl cations stabilized with a methylthio group or geminal methyl groups were generated from the corresponding allylic alcohols under the influence of a Bronsted acid (Tf2NH), respectively. The use of N-nosyl-protected pyrroles as the four-carbon unit was found to give tropinone derivatives in high yield. (C) 2012 Elsevier Ltd. All rights reserved.
Concise [4+3] cycloaddition reaction of pyrroles leading to tropinone derivatives
摘要:
A concise [4+3] cycloaddition reaction of pyrroles with 2-(silyloxy)allyl cations has been developed. The oxyallyl cations stabilized with a methylthio group or geminal methyl groups were generated from the corresponding allylic alcohols under the influence of a Bronsted acid (Tf2NH), respectively. The use of N-nosyl-protected pyrroles as the four-carbon unit was found to give tropinone derivatives in high yield. (C) 2012 Elsevier Ltd. All rights reserved.
An acid-catalyzed [4+3] cycloaddition reaction of N-nosyl pyrroles with 2-(tert-butyldimethylsilyloxy)acrolein has been developed. The reaction of 2-(silyloxy)acrolein with N-nosyl pyrrole was catalyzed by Tf2NH, and a regio- and stereoselective reaction with 2-substituted N-nosyl pyrroles leading to tropinone derivatives possessing tetra-substituted carbon centers was also achieved. High regioselectivities