Facile Synthesis of Spirocyclic Tetrahydroquinolines via C(sp3)–H Functionalization in a Cascade Redox Process

An environmentally benign cascade redox process was developed for the efficient construction of the pharmaceutically significant spirocyclic tetrahydroquinolines via sequential SNAr/Knoevenagel condensation/[1,5]-hydride transfer/cyclization. This green transformation has the features of being catalyst-free, additive-free, operationally simple, and has high step- and atom-economy.