Synthesis of N‐Aryl Isoxazolidines by Photo‐Promoted N‐Selective Arylation of Oximes and Cyclization Using Hypervalent Iodine Reagents and Copper Catalyst

Oximes cause photo‐promoted, copper‐catalyzed N‐selective arylation with diaryl iodonium salts to produce nitrones, which in turn undergo intra‐ or intermolecular 1,3‐dipolar cyclization with olefins to afford N‐aryl isoxazolidines. Hypervalent iodine reagents substituted with either electron‐rich or electron‐deficient groups afford the corresponding N‐aryl isoxazolidines in 26–95% yields. This method offers a faster reaction rate, lower catalyst loading and broader substrate scope of oxime than similar nitrone syntheses employing Chan‐Lam‐Evans coupling. The reaction involves via a radical/single electron transfer (SET) pathway, and does not proceed in the absence of photoirradiation.