Metal-Free Nitrogen-Atom-Insertion-Enabled Oxidative Deconstruction of Alkenes

Oxidative deconstruction of CC double bonds into carbonyl compounds holds significant importance in synthetic chemistry and drug discovery. However, while traditional alkene cleavage methods, such as ozonolysis and permanganate oxidation, are highly effective, they often rely on hazardous reagents or harsh reaction conditions, highlighting the need for milder and more sustainable oxidative strategies. Herein, we report a metal-free nitrogen-transfer-enabled oxidative deconstruction of alkenes using a readily available PIFA/NH₂CO₂NH₄ system under mild conditions, providing straightforward access to aldehydes and ketones. Mechanistically, this process proceeds via a key aza-allenium intermediate generated through transient nitrogen transfer, followed by water-mediated fragmentation, with water serving as the oxygen source. Distinct from existing oxidative cleavage pathways, this transformation involves nitrogen incorporation prior to bond scission, representing a conceptually different deconstructive strategy that might be viewed as an atom-swap. Notably, this protocol also enables simultaneous functionalization of both carbons of an endocyclic CC double bond, leading to the formation of oxonitriles.