Synthesis of Phenanthro[9,10‐
<i>c</i>
]thiophenes by 2,3‐Dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ)‐Promoted Cyclo‐Oxidation
作者:Han Gao、David M. Connors、Nancy S. Goroff
DOI:10.1002/cplu.201900099
日期:2019.6
new method to prepare phenanthro[9,10-c]thiophenes has been developed. In the presence of triflic acid, 3,4-diaryl thiophenes undergo 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-promoted cyclo-oxidation. NMR and computational studies indicate that protonation of the thiophene plays a key role in this reaction. The reaction can be used to prepare phenanthro[9,10-c]thiophene, as well as derivatives
已经开发了一种新的制备菲咯啉[9,10-c]噻吩的方法。在三氟甲磺酸存在下,3,4-二芳基噻吩经历了2,3-二氯-5,6-二氰基-1,4-苯醌(DDQ)促进的环氧化。NMR和计算研究表明,噻吩的质子化在该反应中起关键作用。该反应可用于制备菲[9,10-c]噻吩以及具有烷基,溴和甲氧基取代基的衍生物。但是,反应的产率和选择性取决于取代基的性质和位置。双(3-甲氧基苯基)噻吩在这些条件下反应以57%的收率得到所需的产物,而双(4-甲氧基苯基)噻吩没有产生产物。双(3-溴苯基)噻吩没有反应,但是双(4-溴苯基)噻吩的环氧化以34%的收率提供了所需的产物。