Cascade regioselective synthesis of pyrazoles from nitroallylic acetates and N-tosyl hydrazine
摘要:
A simple, practical, and regioselective synthetic protocol for the formation of pyrazoles was developed. Unlike all other previously reported reactions of nitroallylic acetates, this process was initiated by a S(N)2 reaction at the electrophilic gamma site. A plausible mechanism for the cascade S(N)2-Michael synthesis is proposed. (C) 2013 Elsevier Ltd. All rights reserved.