Synthesis of polysubstituted thiophenes by a catalytic cyclisation of functionalised episulfides
摘要:
Substituted thiophenes are formed by the reaction of 1-alkynyl-2,3-epithioalcohols with a catalytic amount of mercury(II) prepared from HgO and dilute sulfuric acid. (C) 1997 Elsevier Science Ltd.
aryl, and heteroaryl moieties can be prepared in good to excellent yields (up to 99%) by allowing 1,4-butyne-diol, 4-aminobut-2-yn-1-ol, and pent-2-yne-1,5-diol derivatives to react with different electrophiles (I2, IBr, and ICl) at room temperature. Both halogen atoms generated from electrophiles were used effectively. The resulting halides can be further exploited by using palladium-catalyzed coupling