Acid-Catalysed or Radical-Promoted Allylic Substitution of 2-Methylene-2,3-dihydrobenzofuran-3-ols with Thiol Derivatives: a Novel and Expedient Synthesis of 2-(Thiomethyl)benzofurans
作者:Bartolo Gabriele、Raffaella Mancuso、Giuseppe Salerno
DOI:10.1002/ejoc.201000289
日期:——
The 2-thiomethylbenzofuran derivatives 3 are conveniently prepared in good yields through the reactions between the readily available 2-methylene-2,3-dihydrobenzofuran-3-ols 1 and the thiol derivatives 2 (including alkyl thiols, thiophenol, and thioacetic acid). The allylic substitution process may be either acid-catalysed or promoted by radical initiators. In the first case, the reactions are carried
通过易得的2-亚甲基-2,3-二氢苯并呋喃-3-醇1和硫醇衍生物2(包括烷基硫醇、苯硫酚和硫代乙酸)之间的反应,可以方便地以良好的产率制备2-硫甲基苯并呋喃衍生物3。烯丙基取代过程可以由酸催化或由自由基引发剂促进。在第一种情况下,反应在作为质子源的 H 2 SO 4 存在下,在 1,2-二甲氧基乙烷 (DME) 作为溶剂中,在 90 °C 下进行。在偶氮双(异丁腈)(AIBN)或过氧化苯甲酰(BP)作为自由基引发剂的存在下,自由基促进反应发生在 90 °C 的 DME 中。