The key role of R-NHC coupling (R = C, H, heteroatom) and M-NHC bond cleavage in the evolution of M/NHC complexes and formation of catalytically active species

Victor M Chernyshev; Ekaterina A Denisova; Dmitry B Eremin; Valentine P Ananikov

doi:10.1039/d0sc02629h

The key role of R-NHC coupling (R = C, H, heteroatom) and M-NHC bond cleavage in the evolution of M/NHC complexes and formation of catalytically active species

Chem Sci. 2020 Jun 19;11(27):6957-6977. doi: 10.1039/d0sc02629h. eCollection 2020 Jul 21.

Authors

Victor M Chernyshev¹, Ekaterina A Denisova², Dmitry B Eremin^{2

3}, Valentine P Ananikov^{1

2}

Affiliations

¹ Platov South-Russian State Polytechnic University (NPI) , Prosveschenya 132 , Novocherkassk , 346428 , Russia.
² N. D. Zelinsky Institute of Organic Chemistry , Russian Academy of Sciences , Leninsky Prospect 47 , 119991 Moscow , Russian Federation.
³ The Bridge@USC , University of Southern California , 1002 Childs Way , Los Angeles , California 90089-3502 , USA.

Abstract

Complexes of metals with N-heterocyclic carbene ligands (M/NHC) are typically considered the systems of choice in homogeneous catalysis due to their stable metal-ligand framework. However, it becomes obvious that even metal species with a strong M-NHC bond can undergo evolution in catalytic systems, and processes of M-NHC bond cleavage are common for different metals and NHC ligands. This review is focused on the main types of the M-NHC bond cleavage reactions and their impact on activity and stability of M/NHC catalytic systems. For the first time, we consider these processes in terms of NHC-connected and NHC-disconnected active species derived from M/NHC precatalysts and classify them as fundamentally different types of catalysts. Problems of rational catalyst design and sustainability issues are discussed in the context of the two different types of M/NHC catalysis mechanisms.

Publication types

Review