Oxenoid reactivity enabled by targeted photoactivation of periodate.

Abstract

The chemistry of low-valent intermediates continues to inspire new modes of reactivity across synthetic chemistry. But while the generation and reactivity of both carbenes and nitrenes are well-established, difficulties in accessing oxene, their oxygen-based congener, has severely hampered its application in synthesis. Here, we report a conceptually novel approach to oxene generation through the violet-light photolysis of tetrabutylammonium periodate. By revealing an unexpected geometric change upon periodate photoexcitation that facilitates intersystem crossing, we have exploited the near-barrierless dissociation of triplet periodate into oxene. Under these operationally simple conditions, we have demonstrated the epoxidation of a wide range of substituted olefins, revealing unprecedented functional group compatibility. By overcoming the historic challenges associated with employing oxene as an intermediate in organic chemistry, we believe that this platform will inspire the development of new reactive oxygen-based methodologies across industry and academia.