Hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) was studied by using mono- and bidentate p-cymene ruthenium(ii) N-heterocyclic carbene (NHC) complexes as catalyst precursors. In water, all complexes were found to be reduced in situ to form ruthenium nanoparticles (RuNPs) with a high hydrogenation activity. In organic solvents, complexes with monodentate NHC ligands also formed nan...

N-Heterocyclic carbenes (NHCs) have emerged as a powerful class of organocatalysts that mediate a variety of organic transformations. The Benzoin reaction constitutes one of the earliest known carbon-carbon bond-forming reactions catalysed by NHCs. The rapid growth of NHC catalysis in general has resulted in the development of a variety of benzoin and benzoin-type reactions. An overview of such...

In this study, the new benzimidazolium salt (1) containing ether functionalized alkyl group as NHC ligand precursor was synthesized. Ag-NHC complex (2) synthesized by interaction with Ag2O of precursor. The Au-NHC [AuCl(PPh3)] complex. structures prepared all compounds were characterized different spectroscopic methods. 
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The mechanism of the N-heterocyclic carbene (NHC)-catalyzed intramolecular Stetter reaction of salicylaldehyde 1 to yield chromanone 3 has been theoretically studied at the B3LYP/6-31G** level. This NHC-catalyzed reaction takes place through six elementary steps, which involve: (i) formation of the Breslow intermediate IN2; (ii) an intramolecular Michael-Type addition in IN2 to form the new C-C...

Facile synthesis and postsynthetic modification of a rectangular 1,2,4-triazole-based NHC macrocycle have been developed. The silver complex [Ag2(1)2](BF4)2 is derived from the corresponding triazole salt H2-1(BF4)2 upon reaction with Ag2O. The structure of the metallocyclic Ag-NHC complex [Ag2(1)2](BF4)2 was determined by single-crystal X-ray diffraction analysis. The metal-carbene template un...

The coordination of metalloligands to derive modified properties of the metal functionality is one of the interesting strategies practiced in materials chemistry and catalysis. In this work, a pendant terpyridine ligand has been utilized for templating a Cp*Ir(III)(NHC)-based (NHC = N-heterocyclic carbene) oxidation precatalyst to assess its modified oxidative behavior via electrochemical, UV-v...

Stilbene-functionalized NHC accumulated vertical adsorption geometry on Au film, enabling reversible changes in surface potential following photoisomerization. Stronger interaction with Pt film quenched stilbene-NHC influence potential.

The NHC-64 statistical equations for predicting the movement of hurricanes have been in operational use for 4 yr. These equations have continued to perform well. Following the 1966 hurricane season, however, it was apparent that the equations could be improved. A new forecast technique, based on additional data and additional predictors, has been derived. Tests on independent data for 1966 and ...

A dual activation strategy integrating N-heterocyclic carbene (NHC) catalysis and a second Lewis base has been developed. NHC-bound homoenolate equivalents derived from α,β-unsaturated aldehydes combine with transient reactive o-quinone methides in an enantioselective formal [4 + 3] fashion to access 2-benzoxopinones. The overall approach provides a general blueprint for the integration of carb...

Proto-boryl additions to 1,1-disubstituted allenes in the presence of 1.0-5.0 mol % of chiral NHC-Cu complexes, B2(pin)2, and t-BuOH proceed to afford alkenyl-B(pin) products in up to 98% yield, >98:2 site selectivity, and 98:2 er. The enantiomerically enriched alkenylboron products can be converted to otherwise difficult-to-access alkenyl bromides, methyl ketones or carboxylic acids. What's mo...