K 2 S 2 O 8 -Induced [4+2] Annulation of Tertiary Anilines and Alkenes toward Tetrahydroquinolines.

Due to the unique physicochemical properties of heterocyclic compounds, their construction is one of the central issues in synthetic chemistry. Here, we report a K 2 S 2 O 8 -induced protocol for constructing tetrahydroquinolines from bulk chemicals (alkenes and anilines). The merit of this method has been demonstrated by its operational simplicity, wide scope, mild conditions, and transition-metal-free system.