Visible-light induced site-selective C(sp3) –H epoxidation of amides

Oxiranes are among the most valuable reagents in the chemical sciences, with applications that span pharmaceuticals, agrochemicals, and functional materials. Although remarkable progress has been achieved for the construction of oxiranes, the site-selective epoxidation of non-activated C(sp 3 )–H bonds remains under-explored. Herein, we present a photoinitiated, metal-free method for the site-specific epoxidation of remote non-activated C(sp 3 )–H bonds of amides facilitated by amidyl radical-mediated 1,5-hydrogen atom transfer (HAT). The use of a photochemical, radical-mediated approach allows functionalised C(sp 3 )–H bonds to undergo epoxidation under exceptionally mild conditions and circumvents the previously required pre-functionalized alkenes or ketones at specific sites. Notably, direct photoexcitation of available amides allows these reactions to occur at specific locations through intramolecular HAT, therefore representing the first example of highly site-selective epoxidation of non-activated C(sp 3 )–H bonds in molecules, in contrast to all previously reported routes. Furthermore, the follow-up ring-opening transformations and agrochemical activity studies underscore the significant potential application of this approach and products.