T1 - N-Heterocyclic carbenes in organofluorine chemistry

In our previous report, we described how by modifying Kiriy'sconditions6 using N-heterocyclic carbene ligands (NHC)instead of the classical phosphines, we had been able to prepare high molecularweight P3HT with one of the lowest values of polydispersity reported to datefor this molecular weight range (1.09).

KW - N-Heterocyclic carbene (NHC) ligands

T1 - Multicomponent Synthesis of N-Heterocyclic Carbene Complexes

KW - N-Acyl-N-heterocyclic carbene

N2 - A great team: Cyclopentanes with four contiguous stereogenic centers were assembled with excellent diastereo- and enantioselectivity from simple β,γ-unsaturated α-ketoesters and enals in a reaction catalyzed by an N-heterocyclic carbene (NHC) and mediated by a titanium(IV) Lewis acid (see scheme). The presence of a Lewis acid was essential for the desired transformation to occur.

KW - N-Heterocyclic carbene ligand

AB - Two-coordinate copper(I) acetate and copper(I) methyl complexes, bearing an N-heterocyclic carbene (NHC) supporting ligand, have been synthesized and structurally characterized, and the stability of the monodentate acetate has been examined by DFT calculations. The methyl complex readily inserts carbon dioxide at ambient temperature and pressure, regenerating the acetate in near-quantitative yield.

T1 - Synthesis, characterization and reactivity of N-heterocyclic carbene gold(III) complexes

hemilabile NHC ligands, especially their synthesis and ..

It is not surprising that carbohydrate groups have been incorporated into NHC ligands to impose chirality, increase water solubility, and promote biocompatibility.

Chiral N -Heterocyclic Carbenes

AB - A great team: Cyclopentanes with four contiguous stereogenic centers were assembled with excellent diastereo- and enantioselectivity from simple β,γ-unsaturated α-ketoesters and enals in a reaction catalyzed by an N-heterocyclic carbene (NHC) and mediated by a titanium(IV) Lewis acid (see scheme). The presence of a Lewis acid was essential for the desired transformation to occur.

N-heterocyclic carbene ruthenium complexes: Synthesis …

The six memerbered rings focused on 1H-perimidine as the core unit and the design of both bidentate and tridentate NHC ligands to mimic the structural binding relationship of 2,2’- bipyridine (bpy) and 2,2’:6’2”-terpyridine (tpy) with various metal salts.

BT - N-Heterocyclic Carbenes: Effective Tools for Organometallic Synthesis

Carbenes - Chemistry LibreTexts

However, this proved difficult due to associated higher reactivity of the carbene carbon of perimidine with a new side product as a result of this research.

Roles of the NHC ligand and carbohydrate moiety related to these properties are highlighted.

Publications – N-Heterocyclic Carbenes

N-heterocyclic carbene (NHC)-metal complexes have become known as efficient catalysts for numerous transition metal catalyzed processes. An important application of many NHC-metal complexes is in the field of asymmetric catalysis, and this is achieved through the introduction of chiral information on the NHC ligands. Among the asymmetric transformations catalyzed by NHC-metal complexes is asymmetric hydrogenation, which is an attractive process for the synthesis of optically active compounds due to its high atom economy. However, to date, few chiral NHC-metal catalysts have been reported to be highly stereoselective for asymmetric hydrogenation. Over the past few years our group has made some significant breakthroughs within the field of asymmetric hydrogenation using chiral NHC catalysts. We have reported the NHC-Ru catalyzed asymmetric hydrogenation of a wide range of heterocyclic compounds with high regio- and enantioselectivity. The field of chiral NHC-metal complex catalyzed asymmetric hydrogenation is yet to be reviewed; this Perspective aims to provide a concise overview of NHC-metal catalyzed asymmetric hydrogenation to push the further development of this area of chemistry.

The main focus of the research was on the phenanthrene imidazole NHC ligands.

Synthesis of Metal N-Heterocyclic Carbene Complexes

One-pot synthesis Inthe absence of stepwise synthetic methodology, we turned our attention back tothe one-pot route reported by Sellmann (incorporating both the metal and theNHC carbon in a single step), adding methyl groups to the C4 and C5 positionsof the NHC backbone to improve solubility.