1374817-19-2Relevant academic research and scientific papers
Symmetric and dissymmetric N-heterocyclic carbene rhodium(I) complexes: A comparative study of their catalytic activities in transfer hydrogenation reaction
Guelcemal, Sueleyman
experimental part, p. 246 - 251 (2012/07/27)
Six new [RhBr(NHC)(cod)] (NHC=N-heterocyclic carbene; cod=1,5- cyclooctadiene) type rhodium complexes (4-6) have been prepared by the reaction of [Rh(μ-OMe)(cod)]2 with a series of corresponding imidazoli(in)ium bromides (1-3) bearing mesityl (Mes) or 2,4,6-trimethylbenzyl (CH2Mes) substituents at N1 and N3 positions. They have been fully characterized by 1H, 13C and heteronuclear multiple quantum correlation NMR analyses, elemental analysis and mass spectroscopy. Complexes of type [(NHC)RhBr(CO)2] (NHC=imidazol-2-ylidene) (7b-9b) were also synthesized to compare σ-donor/π-acceptor strength of NHC ligands. Transfer hydrogenation (TH) reaction of acetophenone has been comparatively studied by using complexes 4-6 as catalysts. The symmetrically CH2Mes-substituted rhodium complex bearing a saturated NHC ligand (5a) showed the highest catalytic activity for TH reaction.
