Co(III)-alkyl complex- and Co(III)-alkylperoxo complex-catalyzed triethylsilylperoxidation of alkenes with molecular oxygen and triethylsilane.

[reaction: see text] Both a Co(III)-alkyl complex and a Co(III)-alkylperoxo complex were found to catalyze triethylsilylperoxidation of alkenes with O(2) and Et(3)SiH. On this basis, together with the nonstereoselectivity in the Co(II)-catalyzed peroxidation of 3-phenylindene and the formation of the corresponding 1,2-dioxolane from 2-phenyl-1-vinylcyclopropane (a radical clock), we propose a reasonable mechanism for the Co(II)-catalyzed novel autoxidation of alkenes with Et(3)SiH discovered by Isayama and Mukaiyama.