H2O2-based epoxidation of bridged cyclic alkenes with [P{Ti(O2)}2W10O38]7− in monophasic systems: active site and kinetics

✍ Scribed by Feixue Gao; Toshihiro Yamase; Hideo Suzuki

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 275 KB
• Volume: 180
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/s1381-1169(01)00445-9

✦ Synopsis

The H 2 O 2 -based epoxidation of bridged cyclic alkenes in a monophasic system containing low concentrations

(1) (with two 2 -peroxotitanium sites in the anion) has been studied in search of the catalytically active species involved. 31 P NMR spectra of 1, measured under a variety of conditions, revealed that the active species was not hydroperoxotitanium complex

The reaction pathways for the alkene epoxidation are discussed to understand the kinetics (especially the initial [H 2 O 2 ] dependence). It was concluded that the net catalytic reaction for the epoxidation occurred through the two-electron oxidation at the hydroperoxotitanium site in the catalyst.