Two‐step Two‐intermediate Photorelease Bolm‐McCulla Reaction: Dual Release of Nitrene and Atomic Oxygen Reactive Intermediates.

This article is a highlight of the paper by Isor et al. in this issue of Photochemistry and Photobiology. It describes the photolysis of a dibenzothiophene sulfoximine (bearing N‐phenyl imino and S‐oxide groups) to produce two reactive intermediates in tandem. The sulfoximine undergoes a S–N and S–O photocleavage to release phenyl nitrene and atomic oxygen [O(3P)]. The phenyl nitrene dimerizes to azobenzene or is trapped by diethylamine to reach an azepine. From there, atomic oxygen arises in a secondary photolysis of dibenzothiophene sulfoxide. A computational analysis also reveals that the S–N bond is labile for initial nitrene release, with the secondary release of atomic oxygen by S–O cleavage. Whether future sulfoximine scaffolds can produce the reverse order release of O(3P) then nitrene, or release both simultaneously, is yet to be established. Nonetheless, molecules with dual‐intermediate release, such as coupled photoaffinity labeling and cellular oxidation, are worth pursuing. [ABSTRACT FROM AUTHOR]