Cationic copper iminophosphorane complexes as CuAAC catalysts: A mechanistic study

DOI: 10.1021/acs.organomet.0c00348

Authors: Bas Venderbosch (University of Amsterdam) , Jean-pierre H. Oudsen (University of Amsterdam) , Jarl Ivar Van Der Vlugt (University of Amsterdam) , Ties J. Korstanje (University of Amsterdam) , Moniek Tromp (University of Amsterdam)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Organometallics

State: Published (Approved)
Published: September 2020
Diamond Proposal Number(s): 22432

Abstract: We have combined Cu K-edge X-ray absorption spectroscopy with NMR spectroscopy (1H and 31P) to study the Cu-catalyzed azide–alkyne cycloaddition (CuAAC) reaction under operando conditions. A variety of novel, well-defined CuI iminophosphorane complexes were prepared. These ligands, based on the in situ Staudinger reduction when [Cu(PPh3)3Br] is employed, were found to be active catalysts in the CuAAC reaction. Here, we highlight recent advances in mechanistic understanding of the CuAAC reaction using spectroscopic and kinetic investigations under strict air-free and operando conditions. A mononuclear Cu triazolide intermediate is identified to be the resting state during catalysis; cyclization and protonation both have an effect on the rate of the reaction. A key finding of this study includes a novel group of highly modular CuI complexes that are active in the base-free CuAAC reaction.

Journal Keywords: Azides; Hydrocarbons; Copper; Ligands; Pharmaceuticals

Subject Areas: Chemistry


Instruments: B18-Core EXAFS

Documents:
acs.organomet.0c00348.pdf