Chemistry Letters, Vol.48, No.5, 468-470, 2019
Rhodium-catalyzed Synthesis of Benzo[b]thiophene-3-carboxamides via Cyclization of (ortho-Alkynyl)phenyl Sulfides in the Presence of Isocyanates
A facile synthesis of benzo[b]thiophene-3-carboxamides from (ortho-alkynyl)phenyl methoxymethyl sulfides and iso-cyanates was realized. The method involves a tandem-type, cyclization-addition sequence in the presence of a rhodium catalyst. The reactions proceed under considerably mild conditions (room temperature to 50 degrees C), providing an efficient and entirely new route to substituted benzo[b]thiophene-3-carboxamide derivatives.