Divergent α-functionalization of cyclic amines via ring construction by molecular O2 oxidized dearomatization and ring deconstruction by aromatization-driven C–C σ-bond cleavage

An efficient approach to achieve the divergent α-C(sp3)–H functionalization of cyclic amines through a rationally designed ring construction and ring deconstruction strategy was developed. A variety of spiro cyclohexadienone decorated cyclic amines were obtained via ring construction by molecular O2 oxidized dearomatization/cyclization. In addition, the sequential α-C(sp3)–H bond functionalization of cyclic amines was achieved via ring deconstruction through aromatization-driven C–C bond cleavage/intermolecular functionalization with the addition of diverse Grignard reagents or NaBD4.