New strategy for the synthesis of 3-ethynyl-2-(thiophen-2-yl)benzo[b]thiophene derivatives

Pd-catalyzed coupling reactions like the Sonogashira coupling reaction are very useful tools for the formation of new carbon-carbon bonds under mild reaction conditions. Coupling reactions are also used for elaboration of organic compounds in drug and material discovery. Terminal alkynes have a very critical role in Sonogashira coupling reaction. Therefore, design and synthesis of new terminal alkynes are very important for the preparation of organic compounds. In the present study, a novel alkyne 3-ethynyl-2-(thiophen-2-yl)benzo[b]thiophene 13 was synthesized, and it was tested for Sonogashira coupling reaction with different iodoaryl compounds. It was investigated whether our terminal alkyne 13 having a special construction might be a useful precursor for the synthesis of potentially active organic molecules.