title: Silsesquioxane-based homogeneous and heterogeneous epoxidation catalysts developed by using high-speed experimentation.
abstract: 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.
authors.affiliation: Laboratory of Applied Organic Chemistry and Catalysis, DelftChemTech, Technische Universiteit Delft, Julianalaan 136, 2628 BL Delft, The Netherlands.
authors.forename: Paolo P
authors.initials: PP
authors.lastname: Pescarmona
authors.forename: Jan C
authors.initials: JC
authors.lastname: van der Waal
authors.forename: Thomas
authors.initials: T
authors.lastname: Maschmeyer
mesh_terms: D002384:Catalysis; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D008968:Molecular Conformation; D017646:Organosilicon Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D017646:Organosilicon Compounds; D014867:Water; D014025:Titanium; D004121:Dimethyl Sulfoxide