Roderick P Bunschoten, Frederik Peschke, Andrea Taladriz-Sender, Emma Alexander, Matthew J Andrews, Alan R Kennedy, Neal J Fazakerley, Guy C Lloyd Jones, Allan J B Watson, Glenn A Burley
The Cu-catalyzed azide-alkyne cycloaddition (CuAAC) reaction is used as a ligation tool throughout chemical and biological sciences. Despite the pervasiveness of CuAAC, there is a need to develop more efficient methods to form 1,4-triazole ligated products with low loadings of Cu. In this paper, we disclose a mechanistic model for the ynamine-azide (3 + 2) cycloadditions catalyzed by copper(II) acetate. Using multinuclear nuclear magnetic resonance spectroscopy, electron paramagnetic resonance spectroscopy, and high-performance liquid chromatography analyses, a dual catalytic cycle is identified...
May 7, 2024: Journal of the American Chemical Society