Copper Promoted Oxidative Coupling of SnAP Hydrazines and Aldehydes to Form Chiral 1,4,5-Oxadiazepanes and 1,2,5-Triazepanes

SnAP (Sn (tin) amine protocol) hydrazine reagents and aldehydes undergo oxidative, copper mediated coupling to form substituted 1,4,5-oxadiazepanes and 1,2,5-triazepanes. Unlike all prior reactions involving SnAP reagents, the SnAP hydrazine reagents undergo a molecular oxygen-assisted oxidative cyclization. The air- and moisture tolerant transformation accommodates a broad range of groups including electron-rich, electron-poor aromatic, heteroaromatic, and aliphatic aldehydes and is amenable to gram scale synthesis. These unusual, chiral heterocycles have unexpectedly large optical rotations, which may find use in optical materials.