Heterocydic carbene

Ruthenium Precatalysts with JV-Heterocydic Carbene Ligands... 

Keywords Azolium salts AJ-heterocydic carbenes transition metal complexes asymmetric catalysis... 

A -Heterocydic Carbene Complexes in Polymerisation, Oligomerisation and Telomerisation 123... 

A pyridyl bis-N-heterocydic carbene (NHC) ligand has been prepared by Steel and Teasdale based on nudeophilic aromatic substitution of dichloroisonicotinic amides with N-methylimidazole (Scheme 6.122) [250]. Microwave heating of the neat reagents at 140 °C for 10 min provided a 91% yield of the corresponding bis-... 

Peris E (2006) Routes to N-Heterocydic Carbene Complexes. 21 83-116 Fitter S, Dinjus E, lonescu C, Maniut C, Makarczyk P, Patcas F (2008) Evaluation of Supercritical Carbon Dioxide as a Tuneable Reaction Medium for Homogeneous Catalysis. 23 109-147... 

Both, the Kolbe-Schmitt reaction and the dialkyl carbonate route may be beneficial, notably when taking into account the former syntheses used to produce these carboxylato derivatives. Prior to the study of Tommasi et al., the formation of imi-dazolium carboxylates via highly reactive N-heterocydic carbenes (NHC) had been reported, although this rather challenging synthesis could not be extended to an industrial scale. The synthesis of l,3-diisopropyl-4,5-dimethyl-imidazohum-... 

Keywords Catalysis Cross-coupling reaction Electronic properties Metathesis N-heterocydic carbene Topology... 

Application of N-Heterocydic Carbenes in Transition Metal Catalysis... 

Chiral N-Heterocydic Carbenes as Stereodirecting Ligands in Asymmetric Catalysis... 

The introduction of chirafity into NHCs will therefore follow different strategies than those that have proved to be successful in phosphine-based asymmetric catalysis. For example, N-heterocydic carbene units will not create an edge-to-face arrangement of their aryl substituents, a structural feature common to many chiral diphosphines, such as the derivatives of Diop, Binap, Josiphos, Chiraphos and others. Results obtained in asymmetric catalysis, using chiral phosphine ligands, are therefore not directly transferable to the respective NHC-analogues. 

Transition Metal-Catalyzed Reactions Using N-Heterocydic Carbene Ligands (Besides Pd- and Ru-Catalyzed Reactions)... 

Abstract Major advances in transition-metal catalyzed reactions have taken place since the discovery of N-heterocydic carbenes (NHCs). This review provides a summery of recent M-NHC catalyzed reactions including cycloadditions, rearrangements, coupling reactions, polymerizations, and the additions of H-X. 

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