Catalyst system based on polymer compounds comprising silasesquioxane-metal complexes

Catalyst systems based on a polymer compound having a molecular weight Mn of greater than 1000 g/mol, and comprising at least one silasesquioxane-metal complex, especially useful for the oxidation and oximation of organic compounds using peroxides; processes for preparation of such catalytic systems; and processes for use of such catalytic systems

Oligomeric silasesquioxanes and a process for preparing oligomeric silasesquioxanes

Oligomeric silasesquioxanes having the formula R6Si6O9 wherein R is alkyl, cycloalkyl other than cyclohexyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, and/or heteroaryl, and the structure I; processes for preparing oligomeric silasesquioxanes of formula R6Si6O9 wherein R is alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, and/or heteroaryl; processes of using such oligomeric silasesquioxanes; and products obtained thereby

Titanium silsesquioxanes grafted on three-dimensionally netted polysiloxanes: catalytic ensembles for epoxidation of alkenes with aqueous hydrogen peroxide

Catalytic ensembles suitable for alkene epoxidation with aqueous hydrogen peroxide are now accessible. They are made by grafting robust titanium silsesquioxane sites onto dimethylsiloxane polymers (see picture) followed by cross-linking to three-dimensionally netted polymers

Steric factors affecting the Bronsted acidity of aluminosilsesquioxanes

By reacting AlMe3 with two equivalents of (c- C5H9)(7)Si7O9(OH)(2)OSiR3, the corresponding Bronsted acidic aluminosilsesquioxanes [(c-C5H9)(7)Si7O11(OSiR3)]Al[(c- C5H9)(7)Si7O10(OH)OSiR3] [SiR3 = SiMe3 (1a), SiMePh2 (1b)] are obtained. These complexes readily react with triethylamine to yield the corresponding ammonium salts {[(c- C5H9)(7)Si7O11(OSiR3)](2)Al}(-)(HNEt3)(+) (2a,b). Hydrogen bonding between the acidic SiO(H)-->Al proton and the pendant silyl ether function is effectively reduced by increasing the steric bulk of the silyl ether substituents, resulting in a higher acidity for 1b compared to that of 1a. With the silsesquioxane ligand (c-C5H9)(8)Si8O11 (OH)(2), which lacks pendant silyl ether functions, the acidic proton cannot satisfactorily be stabilized and this renders the putative Bronsted acid [(c-C5H9)(8)Si8O13]Al[(c-C5H9)(8)Si8O12(OH)] unstable. In the absence of proton accepters, the disproportionation product [(c-C5H9)(8)Si8O13](3)Al-2 (3) is formed instead of the Bronsted acid. However, in the presence of triethylamine, the initially formed Bronsted acid readily transfers its proton to the amine, affording the ammonium salt {[(c-C5H9)(8)Si8O13](2)Al}(-){HNEt3}(+) (4

Catalyst system based on polymer compounds comprising silasesquioxane-metal complexes

Abstract of US2002137625 Catalyst systems based on a polymer compound having a molecular weight Mn of greater than 1000 g/mol, and comprising at least one silasesquioxane-metal complex, especially useful for the oxidation and oximation of organic compounds using peroxides; processes for preparation of such catalytic systems; and processes for use of such catalytic systems

Catalyst system based on polymer compounds comprising silasesquioxane-metal complexes

Abstract of US2002137625 Catalyst systems based on a polymer compound having a molecular weight Mn of greater than 1000 g/mol, and comprising at least one silasesquioxane-metal complex, especially useful for the oxidation and oximation of organic compounds using peroxides; processes for preparation of such catalytic systems; and processes for use of such catalytic systems

Preparation of oligosilsesquioxanes and their use in the synthesis of incompletely-condensed silsesquioxanes and catalysts or their precursors

Oligosilsesquioxanes I [R = (cyclo)alkyl, (cyclo)alkenyl, (cyclo)alkynyl, aryl, heteroaryl] and their metal complexes or precursors are prepd. Adding 100 mL H2O cautiously to a stirred, boiling soln. of 100 g C6H11SiCl3 in 400 mL acetone, stirring at room temp. for 168 h, washing the resulting solids with acetone, drying, and stirring 1 part solid with 5 parts pyridine for 30 min gave 21.0% I (R = C6H11). Prepn. of Ti complexes and of the silsesquioxanes R6Si6O7(OH)4 are exemplified. [on SciFinder (R)

Preparation of oligosilsesquioxanes and their use in the synthesis of incompletely-condensed silsesquioxanes and catalysts or their precursors

Oligosilsesquioxanes I [R = (cyclo)alkyl, (cyclo)alkenyl, (cyclo)alkynyl, aryl, heteroaryl] and their metal complexes or precursors are prepd. Adding 100 mL H2O cautiously to a stirred, boiling soln. of 100 g C6H11SiCl3 in 400 mL acetone, stirring at room temp. for 168 h, washing the resulting solids with acetone, drying, and stirring 1 part solid with 5 parts pyridine for 30 min gave 21.0% I (R = C6H11). Prepn. of Ti complexes and of the silsesquioxanes R6Si6O7(OH)4 are exemplified. [on SciFinder (R)