| 摘要 |
Polyhedral oligomeric silsesquioxanes (POSS) linked ligand of the general formula (I)
L[(R1a)n-1(SiO1,5)nR2a]k[(R1b)n-1SiO1,5)nR2b]l[(R1c)n-1SiO1,5)nR2c]m (I)in which (R1a,b,c)n-1(SiO1,5)n is a polyhedral oligomeric silsesquioxanes (POSS) with n=4, 6, 8, 10, 12, 14, 16 or 18 andR1a, R1b, R1c is each independently selected from the group consisting of same or different branched or linear C1-C20 alkyl chains, cyclo alkyl, C1-C20 alkoxy, aryl, aryloxy, heteroaryl and arylalkyl groups,k, l, m is 0 or 1 provided that k+l+m≧1,R2a, R2b, R2c is a spacer that binds the polyhedral oligomeric silsesquioxane (POSS) to the ligand L and ligand L is an uncharged electron donor. |
| 主权项 |
1. A catalyst comprising a transition metal and a polyhedral oligomeric silsesquioxane (POSS)-linked ligand of formula (I):
L[(R1a)n-1(SiO1,5)nR2a]k[(R1b)n-1SiO1,5)nR2b]l[(R1c)n-1SiO1,5)nR2c]m (I) wherein: (R1a,b,c)n-1(SiO1,5)n is a polyhedral oligomeric silsesquioxane (POSS) with n=4, 6, 8, 10, 12, 14, 16 or 18 and R1a, R1b, R1c are each independently selected from the group consisting of the same or different branched or linear C1-C20 alkyl chains, cyclo alkyl, C1-C20 alkoxy, aryl, aryloxy, heteroaryl and arylalkyl groups, k, l, and m are 0 or 1, provided that k+l+m≧1, R2a, R2b, R2c are spacers that bind the polyhedral oligomeric silsesquioxane (POSS) to the ligand L, and are each independently selected from the group consisting of linear or branched C1-C20 alkyl, C3-C10 cyclic alkyl, C1-C20 alkoxy, C2-C20 alkenyl, C2-C20 alkenyloxy, aryloxy, C1-C20 alkylthio, C1-C20 carboxylate, aryl or heteroaryl, C1-C20 alkyl halogenide, annulated aryl or heteroaryl, and C3-C10 cyclic alkyl groups which, in turn, may each be further substituted with one or more groups selected from: hetero atoms or aryl groups, ether, polyether, polythioether, amino, and aryl bridged alkyl chain where the aryl moiety can be further substituted and ligand L is an N-heterocyclic carbene; wherein said catalyst has a molecular weight of 1500 to 3000 g/mol; and wherein: said POSS-linked ligand is optionally part of a bidentate polyhedral oligomeric silsesquioxane-linked ligand of general formula (III): wherein Q is selected from: a branched or linear substituted or unsubstituted alkyl chain with a chain length ranging from C1 to C20 and a unsubstituted or substituted cyclic alkyl, aryl or heteroaryl group where the aryl and heteroaryl moieties can be further substituted; and wherein said catalyst is:
i) soluble and catalytically active in one or more organic solvents, thereby permitting homogeneous catalysis in said solvents; andii) filtratable by membrane filtration. |
