Epoxidation of olefins catalysed by polystyrene-supported tellurinic acid

1 Epoxidation of olefins catalysed by polystyrene-supported tellurinic acid 

Anchored aryltellurinic acid has a catalytic activity on the epoxidation of olefins.The reagent is prepared by reaction of tellurium tetrachloride with divinylbenzene-styrene copolymer, followed by hydrolysis of the formed trichloride. 

1-methyl cyclohexene (54), cyclohexene (21), 3-methyl cyclohexene (21), frans-2-butene (15), styrene (10), c/s-2-octene (43), trans-2-octene (4.2), 

The catalytic activity is dependent on the polymeric structure of the reagent, no epoxidation being observed with free tellurinic acids. 

The epoxidation is accelerated by increasing alkyl substitution and is stereospecific as demonstrated by the retained configuration of the olefinic bond. 

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