Titanosilicates. epoxidation, mechanisms

D. Tantanak, M. A. Vincent, 1. H., Hillier, Elucidation of the mechanism of alkene epoxidation by hydrogen peroxide catalyzed by titanosilicates A computational study, Chem. Commun. (1998) 1031. 

H. Munakata, Y. Oumi, A. Miyamoto, A DET study on peroxo-complex in titanosilicate catalyst Hydrogen peroxide activation on titanosilicalite-1 catalyst and reaction mechanisms for catalytic olefin epoxidation and for hydroxylamine formation from ammonia, J. Phys. Chem. B 105 (2001) 3493. 

Scheme 1. Mechanisms of epoxidation on titanosilicates. (View this art in color at www.dekkerxom.)...

A much more convenient method of obtaining five-membered cyclic carbonates is the insertion of gaseous carbon dioxide into the appropriate oxirane ring (Scheme 7). The catalyst development and the reaction mechanisms over alkali metal halides, " organic bases, " metal oxides, zeolite,titanosilicates, " and metal com-plexes " have been reported for the synthesis of cyclic carbonates from CO2 and epoxides. 

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