Silsesquioxane-based homogeneous and heterogeneous epoxidation catalysts developed by using high-speed experimentation.

Chemistry

Laboratory of Applied Organic Chemistry and Catalysis, DelftChemTech, Technische Universiteit Delft, Julianalaan 136, 2628 BL Delft, The Netherlands.

Published: April 2004

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A set of new titanium-silsesquioxane epoxidation catalysts was discovered by exploring the hydrolytic condensation of a series of trichlorosilanes in highly polar solvents by means of high-speed experimentation techniques. The most promising silsesquioxane leads were prepared on a conventional laboratory scale and fully characterised. The lead generated by the hydrolytic condensation of tBuSiCl(3) in DMSO consisted of a set of incompletely condensed silsesquioxane structures, whereas that obtained from the hydrolytic condensation of tBuSiCl(3) in water consisted of a single silsesquioxane structure, tBu(2)Si(2)O(OH)(4). This is the first reported example of the use of this silsesquioxane as a precursor for active Ti catalysts. The Ti complexes prepared with tBu(2)Si(2)O(OH)(4) were supported on silica to produce active heterogeneous epoxidation catalysts.

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http://dx.doi.org/10.1002/chem.200305387DOI Listing

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