A Convenient Formal [4+2] Heterocylization Route to Bis(triflyl)tetrahydroquinolines.

We report the sustainable and efficient synthesis of a new type of quinoline derivatives bearing one or two SO2 CF3 groups. The protocol is metal-, catalyst- and irradiation-free, involves the use of readily available and stable precursors, and avoids the formation of side products. Also, the mild conditions of the process allow the tolerance of a wide range of functional groups.