Diastereoselective Synthesis of N‑Aryl Tetrahydroquinolines and N‑Aryl Indolines by the Tandem Reaction of Arynes

A tandem reaction of arynes with α- or β-amino ketones has been revealed. Arynes react with β-amino ketones through a cascade insertion–cyclization process to afford N-aryl tetrahydroquinolines in good yield with excellent anti-selectivity. Meanwhile, the coupling of arynes with α-amino ketones produces multisubstituted indolines in high yield with syn-selectivity. A quaternary carbon center can be constructed in this process, and the reaction can be easily scaled up.