Epoxidation alkenes containing carbonyl groups

Benzylic C-H bonds undergo oxidative esterification with TBHP in the presence of tetrabutylammonium iodide as catalyst and carboxylic acids in good to excellent yields. A free radical process has been proposed. Asymmetric epoxidation of electron-poor terminal alkenes bearing different carbonyl groups has been achieved with a cinchona thiourea/TBHP system. The corresponding epoxides, containing a quaternary stereocentre, were isolated in yields up to 98% and enantioselectivity up to 99%. A direct oxidative CDC of indole with A-aryltetrahydroisoquinolines in the 0 presence of a gold catalyst and TBHP resulted in the formation of a variety of alkylated heteroarenes (Scheme 24). ... 

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