Metal-free, one-pot tandem reactions of o-(1-alkynyl)benzamides proceed smoothly in the presence of Lawesson’s reagent leading to 1,3-dihydrobenzo[c]thiophene-imine derivatives in moderate to excellent yields under mild conditions. The method is highly regiospecific for the o-(1-alkynyl)benzothioamide, and only the five-membered-ring product is generated via a 5-exo-dig cyclization involving the
在Lawesson试剂的存在下,o-(1-炔基)苯甲酰胺的无金属单锅串联反应可顺利进行,从而在温和的条件下以中等至极好的收率得到1,3-二氢苯并[ c ]噻吩-亚胺衍生物。该方法对邻-(1-炔基)苯并硫代酰胺具有高度的区域特异性,并且通过涉及硫原子的5- exo- dig环化仅生成五元环产物。 邻-(1-炔基)苯并硫代酰胺-串联反应-Lawesson试剂-无金属-杂环