Diverse indole derivatives are obtained by a cascade process involving dithiocyanation or selenocyanation and cyclization of ortho-alkynylanilines under mild conditions with NH₄SCN/KSeCN. Experiments are undertaken to shed light on the radical reaction mechanism and investigate the versatility of the transformation.

A photoinduced cyclization and dithiocyanation/selenocyanation of ortho-alkynylanilines with NH₄SCN/KSeCN provide various dithiocyanated and selenocyanated indoles. The structure of the indole framework is confirmed by single-crystal X-ray diffraction. In addition, a series of experiments investigating scale-up, other starting materials, and radical inhibition/capture are carried out to study the application and reaction process of this cascade system.