One-Pot Synthesis of Substituted Thiophene and Furan Derivatives from Terminal Alkynes

The development of efficient and sustainable methods for the synthesis of thiophene and furan derivatives is an important task because of the central role of this class of compounds in many natural products, pharmaceuticals and designed materials applications. In this work, a highly efficient selective synthesis of 2,5-disubstituted furan, 2,5-disubstituted thiophene derivatives, benzo[b]furan and benzo[b]thiophene derivatives using terminal alkynes has been developed. This one-pot procedure involves C(sp)-C(sp) oxidative coupling reaction, the selective hydration and intramolecular annulation of two C≡C triple bond which is a promising synthetic strategy. Meanwhile, the benzo[b]furan and benzo[b]thiophene derivatives were facilely synthesized via Sonogashira coupling reaction, regioselective C—F bond hydration and annulation process in good yield. This reaction was a convenient and simple pathway for the synthesis of the thiophene or furan derivatives.