One‐Pot Synthesis of 2‐(Aryl/Alkyl)amino‐3‐cyanobenzo[<i>b</i>]thiophenes and Their Hetero‐Fused Analogues by Pd‐Catalyzed Intramolecular Oxidative C–H Functionalization/Arylthiolation

Abstract

We have developed a high‐yielding synthesis for substituted 2‐(aryl/alkyl)amino‐3‐cyanobenzo[ b ]thiophenes and their hetero‐fused analogues by using a palladium‐catalyzed intramolecular oxidative C–H functionalization/arylthiolation reaction of in situ generated N ‐(alkyl/aryl)thioamides, prepared from readily available (hetero)arylacetonitriles and alkyl/aryl isothiocyanates. This protocol was then extended to the synthesis of amino‐substituted benzothieno[2,3‐ b ]quinolines by employing a triflic acid mediated intramolecular cyclocondensation of the prepared 2‐arylamino‐3‐cyanobenzo[ b ]thiophenes.