Herein we report the anaerobic cleavage of alkenes into carbonyl compounds using nitroarenes as oxygen transfer reagents under visible light. This approach serves as a safe and practical alternative to mainstream oxidative cleavage protocols, such as ozonolysis and the Lemieux–Johnson reaction. A wide range of alkenes possessing oxidatively sensitive functionalities underwent anaerobic cleavage to generate carbonyl derivatives with high efficiency and regioselectivity. Mechanistic studies support that the transformation occurs via direct photoexcitation of the nitroarene followed by a non-stereospecific radical cycloaddition event with alkenes. This leads to 1,3,2- and 1,4,2-dioxazolidine intermediates that fragment to give the carbonyl products. A combination of radical clock experiments and in situ PhotoNMR spectroscopy revealed the identities of the key radical species and the putative aryl dioxazolidine intermediates, respectively.
In the new version of the manuscript, some minor edits to the introduction were made. The mechanistic section has been updated to include new radical clock studies and photoNMR experiments. The results support the updated mechanism shown in Scheme 2. For the SI, new experimental details and spectra were added for these additional studies. The authors, Alana Duke and Joshua Paolillo, have been given co-second authorship with Taylor Vacala based on their experimental contributions during the revision of this manuscript. The authors’ order list has been changed to reflect this.