The “weak base route” leading to transition metal–N-heterocyclic carbene complexes

N-Heterocyclic carbenes (NHCs) are nowadays ubiquitous in organometallic chemistry and catalysis. A simple synthetic route to these is presented.

Synthesis, characterization, biological determination and catalytic evaluation of ruthenium(ii) complexes bearing benzimidazole-based NHC ligands in transfer hydrogenation catalysis

A new series of ruthenium (ii) N-heterocyclic carbene complexes has been synthesized via transmetalation. The obtained complexes were applied to transfer hydrogenation of ketone derivatives.

‘Click’ generated 1,2,3-triazole based organosulfur/selenium ligands and their Pd(ii) and Ru(ii) complexes: their synthesis, structure and catalytic applications

Sonogashira and Suzuki–Miyaura coupling were catalyzed with Pd(ii) complexes (0.001–2 mol%), and transfer hydrogenation (in water–glycerol) was catalyzed with Ru(ii) complexes (≤0.4 mol%).

A facile synthetic route to benzimidazolium salts bearing bulky aromatic N-substituents

An atom-economic synthetic route to benzimidazolium salts is presented. The annulated polycyclic systems: 1,3-bis(2,4,6-trimethylphenyl)-1H-benzo[d]imidazol-3-ium chloride (1-Cl), 1,3-bis(2,6-diisopropylphenyl)-1H-benzo[d]imidazol-3-ium chloride (2-Cl), 1,3-diphenyl-1H-benzo[d]imidazol-3-ium chloride (3-Cl), and 1,3-di(pyridin-2-yl)-1H-benzo[d]imidazol-3-ium chloride (4-Cl) were prepared in a two-step synthesis avoiding chromatographic work-up. In the key step triethyl orthoformate is reacted with the corresponding N¹,N²-diarylbenzene-1,2-diamines and then further transformed in situ, by alkoxy abstraction using trimethylsilyl chloride (TMSCl), and concomitant imidazole ring closure.

Benzimidazolin-2-ylidene N-heterocyclic carbene complexes of ruthenium as a simple catalyst for the N-alkylation of amines using alcohols and diols

Simple non-chelating ruthenium benzimidazolin-2-ylidene complexes as efficient N-alkylation catalysts using alcohols and diols following a hydrogen borrowing strategy.