Synthesis of 2,3-disubstituted thiophenes from 2-aryl-3-nitro-cyclopropane-1,1-dicarboxylates and 1,4-dithiane-2,5-diol
作者:Thangavel Selvi、Govindhraj Vanmathi、Kannupal Srinivasan
DOI:10.1039/c5ra09111j
日期:——
A two-step synthesis of 2,3-disubstituted thiophenes from trans-2-aryl-3-nitrocyclopropane-1,1-dicarboxylates and 1,4-dithiane-2,5-diol is described. The nitrocyclopropane dicarboxylates when treated with boron trifluoride etherate formed aroylmethylidene malonates in situ through ring-opening followed by rearrangement and a Nef reaction, and subsequent addition of 1,4-dithiane-2,5-diol and triethylamine
描述了由反式-2-芳基-3-硝基环丙烷-1,1-二羧酸酯和1,4-二噻吩-2,5-二醇两步合成2,3-二取代噻吩的方法。当用三氟化硼醚化物处理时,硝基环丙烷二羧酸盐通过开环原位形成芳酰基亚甲基丙二酸酯,随后进行重排和Nef反应,随后向同一烧瓶中加入1,4-二硫代-2,5-二醇和三乙胺,通过以顺序一锅法进行串联的硫杂-迈克尔加成/醛醇缩合反应。对-甲苯磺酸处理后的产物四氢噻吩进行脱水,然后进行单脱碳乙氧基化,得到2,3-二取代的噻吩。