Phosphines with 2-imidazolium ligands enhance the catalytic activity and selectivity of rhodium complexes for hydrosilylation reactions

Phosphines with 2-imidazolium ligands can specifically vary their physical and chemical properties by altering the attached substituents. Rhodium complexes (1b–7b) exhibited excellent catalytic activity and selectivity for hydrosilylation of olefins. The selectivity of the β-adduct clearly increased when the length of the alkyl chain bound to the imidazolium cation increased. Rhodium complex 1b in BMimPF6 can be reused without noticeable loss of catalytic activity and selectivity.

Graphical abstractPhosphines with 2-imidazolium can specifically vary their physical and chemical properties by altering the attached substituents. Rhodium complexes employing 2-imidazolium phosphines as ligands exhibit excellent catalytic activity and selectivity. It is possible that close proximity of the positive charge to the phosphorus atom greatly enhances the catalytic activity and can afford highly efficient catalytic activity.Figure optionsDownload full-size imageDownload as PowerPoint slide