Lewis Acid‐Assisted Transition Metal‐Free Aminocyanation of Alkynes with Arylamines and N‐Cyanosuccinimide

A transition-metal-free aminocyanation of aryl alkynes has been achieved using indium tribromide, InBr3 or B(C6F5)3 as a Lewis acid. This aminocyanation protocol features with non-toxic cyanide source, a good substrate scope and valuable aminocyanation products. Mechanistic studies reveal the complex formation between Lewis acid and alkyne to produce in situ alkyne nitrile as a key intermediate. Further hydroamination of alkyne nitrile with arylamines affords the E-selective (majorly) β-aminoacrylonitrile derivatives.