Chemo-divergent Cyano Group Migration: Involving Elimination and Substitution of the Key α-Thianthrenium Cyano Species.

Herein, we report a light-driven, radical-type cyano migration in the absence of a photocatalyst, enabling a chemo-divergent synthesis of ( Z )-alkenyl nitriles and ketones. Trifluoromethyl thianthrenium salt (TT-CF 3 + OTf - ) plays multiple roles: (a) absorbing light to generate trifluoromethyl radicals to initiate the reaction and (b) forming α-thianthrenium cyano species by in situ capture of TT •   + . ( Z )-Alkenyl nitriles were formed through the elimination of thianthrenium salts, and aryl ketones were obtained via the nucleophilic substitution of thianthrenium salts.