Nickel-catalyzed cycloisomerization of enynes: catalyst generation via C–H activation of carbene ligands
作者:Thomas N. Tekavec、Janis Louie
DOI:10.1016/j.tet.2008.03.071
日期:2008.7
The combination of Ni(0) and an N-heterocyclic carbene acts as a precatalyst for the cycloisomerization of enynes to afford 1,3-dienes. During the course of the reaction, a nickel hydride is formed from oxidative addition of the ortho C-H on the carbene ligand. Deuterium labeling studies are presented. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.
Nickel-Catalyzed Cycloadditive Couplings of Enynes and Isocyanates
作者:Brendan R. D’Souza、Janis Louie
DOI:10.1021/ol901703t
日期:2009.9.17
A mild and general route for preparing dienamides is described. Nickel imidazolylidene complexes were used to mediate cycloadditive coupling between enynes and isocyanates. Dienamides were prepared in excellent yields and with good E:Z selectivity. These dienamides can be further manipulated through oxidative cyclization methods. When a terminal enyne is employed, cyclization affords a lactam rather than a dienamide.