We report herein on a catalytic system involving palladium and copper to achieve the cyclization of N-arylcyanothioformamides and the synthesis of 2-cyanobenzothiazoles. The C-H functionalization/intramolecular C-S bond formation reaction was achieved in the presence of air, using 2.0 equiv of an inorganic additive (KI). In many cases, the reaction led to a sole product regioselectively obtained in good yields, allowing the synthesis of a wide range of substituted 2-cyanobenzothiazole derivatives, providing valuable building blocks for the design of more complex heterocyclic or molecular labeling systems.
Keywords: 2-cyanobenzothiazoles; 4,5-dichloro-1,2,3-dithiazolium chloride; C-S bond formation; N-arylcyanothioformamides; N-arylimino-1,2,3-dithiazoles.