An efficient approach to H-pyrazolo[5,1-a]isoquinolines via a silver triflate-catalyzed reaction of N′-(2-alkynylbenzylidene)hydrazide with allenoate
摘要:
A silver triflate-catalyzed reaction of N'-(2-alkynylbenzylidene)hydrazide with allenoate under mild conditions is described, which provides an efficient approach to diverse H-pyrazolo[5,1-alisoquinolines. This reaction proceeds with a wide substrate scope with good functional groups tolerance. (C) 2012 Elsevier Ltd. All rights reserved.
An efficient one-pot tandem cyclization/[3 + 2] cycloaddition reaction of N'-(2-alkynylbenzylidene)hydrazides with ethyl 4,4,4-trifluorobut-2-ynoate under silver triflate-catalyzed or electrophile-mediated conditions is described. Various trifluoromethylated pyrazolo[5,1-a]isoquinolines were afforded in moderate to excellent yield by this developed method.
Formal [5+3] Cycloaddition of Zwitterionic Allylpalladium Intermediates with Azomethine Imines for Construction of N,O-Containing Eight-Membered Heterocycles
A formal [5+3] cycloaddition of zwitterionicallylpalladiumintermediates with 1,3‐dipoles is developed, providing N,O‐containing eight‐membered heterocyclic compounds in high yields. Catalytically generated zwitterionicallylpalladiumintermediates in situ from vinylethylene carbonates or vinyloxiranes acted as dipolarophile.