Studies on asymmetric epoxidation of olefins catalyzed by arylseleninic acids having hypervalent coordinate bond

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Substituted diphenyl diselenides such as bis[2-(-)-menthyloxycarbonylpehnyl]diselenide(1), bis[2-(R)-α-methylbenzyloxycarbonylphenyl]diselenide(2), Bis[2, 6-bis(-)-menthyloxycarbonyl-phenyl]diselenide(3), and bis{2-methyl-6-[α-((R)-2-phenylpropionyloxy)benzyl]phenyl}diselenide(4)were synthesized, and asymmetric epoxidations were tried using hydrogen perioxide and a catalytic amount of the chiral diaryl diselenides. Diary diselenides are supposed to be oxidized to corresponding arylseleninic acid during the reaction. An optical yield of up to 36% ee has been attained for the epoxidation of trisubstituted olefins.During the course of the research rr Alkyl aryl selenides with an ortho substituent were found to be superior to the corresponding para isomers as starting materials for the preparation of terminal olefins when hydrogen peroxide was used as the oxidant.