Polysilsesquioxane (POSS)-linked Imidazole-based Carbene and Phosphine Ligands for Transition Metal Catalysts

摘要

Polyhedral oligomeric silsesquioxanes (POSS) linked ligand of the general formula (I)
€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ L [(R 1a ) n-1 (SiO 1,5 ) n R 2a ] k [(R 1b ) n-1 SiO 1,5 ) n R 2b ] l [(R 1c ) n-1 SiO 1,5 ) n R 2c ] m €ƒ€ƒ€ƒ€ƒ€ƒ(I)
in which (R 1a,b,c ) n-1 (SiO 1,5 ) n is a polyhedral oligomeric silsesquioxanes (POSS) with n = 4, 6, 8,10, 12, 14, 16 or 18 and
R 1a , R 1b ,R 1c is each independently selected from the group consisting of same or different branched or linear C 1 -C 20 alkyl chains, cyclo alkyl, C 1 -C 20 alkoxy, aryl, aryloxy, heteroaryl and arylalkyl groups,
k, I, m is 0 or 1 provided that k+l+m ‰¥ 1,
R 2a , R 2b , R 2c is a spacer that binds the polyhedral oligomeric silsesquioxane (POSS) to the ligand L and ligand L is an uncharged electron donor.