Advances in the Synthesis and Applications of N-Heterocyclic Carbene Metal Complexes with a Focus on the Weak Base Route

Abstract

N-heterocyclic carbene (NHC) ligands have evolved from being simple lab curiosities to tertiary phosphine mimics to finally take center stage as unique supporting ligands in organometallic chemistry, homogeneous catalysis, and more recently in medicinal chemistry and materials science applications. Some of these aspects are presented here from a perspective of researchers that have been fascinated by the area for quite some time.

Platinum(0)-η2-1,2-(E)ditosylethene Complexes Bearing Phosphine, Isocyanide and N-Heterocyclic Carbene Ligands: Synthesis and Cytotoxicity towards Ovarian and Breast Cancer Cells

“…N -heterocyclic carbene (NHC) ligands have emerged as pivotal components in modern organometallic chemistry, revolutionizing catalytic processes and enhancing the versatility of transition metal complexes. Since their discovery in the 1980s, NHC ligands have garnered significant attention owing to their unique electronic and steric properties, which make them ideal candidates for a wide range of applications [ 22 ].…”

“…2-methyl-6-((phenylthio)methyl)pyridine, Pt(dba) 2 ( E )-1,2-ditosylethene and silver-NHC complexes 5a , b were synthetized according to the published procedures [ 21 , 22 , 23 , 24 , 25 ].…”

Dinuclear NHC–gold(i)–thiolato and –alkynyl complexes: synthesis, anticancer activity, and catalytic activity in lactonization reactions

“…24,27 The latter are usually considered as an attractive alternative to tertiary phosphines, owing to their ability to form strong bonds with transition metals. 28…”

The facile alkylation and iodination of imidazol(in)ium salts in the presence of cesium carbonate

“…5 Most investigations carried out so far focused on the synthesis of transition metal complexes bearing NHC ligands via a concerted metalation/deprotonation path. 6 Yet, recent work from our Laboratory has shown that imidazol(in)ium salts could easily perform a nucleophilic addition on CS 2 in the presence of Cs 2 CO 3 to afford zwitterionic dithiocarboxylate adducts (Scheme 1a). 7 Thus, we wanted to determine whether NHC·HX salts could also undergo a nucleophilic substitution under the same experimental conditions (Scheme 1b).…”