The Janus Face of the X Ligand in the Copper-Catalyzed Azide–Alkyne Cycloaddition

详细信息    查看全文

• 作者：Liqun Jin ; Erik A. Romero ; Mohand Melaimi ; Guy Bertrand
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：December 23, 2015
• 年：2015
• 卷：137
• 期：50
• 页码：15696-15698
• 全文大小：271K
• ISSN：1520-5126

文摘

To understand the effect of the anion (X) in the copper-catalyzed azide–alkyne cycloaddition (CuAAC) catalytic process, the kinetic profiles of the successive steps of the catalytic cycle have been studied by performing stoichiometric reactions using copper complexes LCuX in which L is a cyclic (alkyl)(amino)carbene (CAAC) ligand and X = OTf, Cl, OAc, OPh, or OtBu. Basic ligands favor the metalation step but disfavor the formation of the catalytically active σ,π-bis(copper) acetylide, whereas non-nucleophilic ligands favor the latter but slowly promote the former. We show that acetate is a good compromise, and in addition, it is very efficient in the proto-demetalation step.