One‐Pot Synthesis of 2‐Aminothiophenes by Au(I)‐Catalyzed Cascade Reaction Including Hydrothiolation, Thio‐Claisen Rearrangement, and Cycloisomerization

The cascade reaction of ynamides with propargyl thiols by Au(I) catalysis involving regioselective hydrothiolation, thio‐Claisen rearrangement, and cycloisomerization to generate 2‐aminothiophenes in a one‐pot manner is described. In this reaction, the selection of reaction temperature is crucial, with the initial step, namely hydrothiolation, conducted at a low temperature (40 °C), followed by the subsequent reaction requiring an increase in temperature (>110 °C). Furthermore, it was revealed that multi‐substituted anilines could be synthesized from the resulting 2‐aminothiophenes.