Chemical and spectroscopic properties of the 3-hydroxythiophene [thiophen-3(2H)-one] system
作者:Gordon A. Hunter、Hamish McNab
DOI:10.1039/c0nj00320d
日期:——
3-Hydroxythiophene 1 spontaneously dimerises to 4,5-dihydro-5-(3-hydroxythien-2-yl)thiophen-3(2H)-one 14. 3-Hydroxythiophenes 1E and 4–10E exist in solvent-dependent equilibrium with their thiophen-3(2H)-one 1K and 4–10K tautomers; the amount of hydroxy tautomer is greater than in the case of the corresponding 3-hydroxypyrroles. 3-Hydroxythiophenes are much less reactive to electrophiles than corresponding
3-羟基噻吩 1自发二聚为4,5-二氢-5-(3-羟基噻吩-2-基)噻吩-3(2 H)-one 14。3- Hydroxythiophenes 1E和4- 10E中存在与溶剂依赖性平衡他们的噻吩3(2 H)-one 1K和4- 10K互变异构体; 羟基互变异构体的量大于相应的3-羟基吡咯的情况。3-羟基噻吩对亲电试剂的反应性远低于相应的3-羟基吡咯,但是5-甲基硫烷基衍生物10在2位与甲氧基亚甲基Meldrum的酸会经历Vilsmeier甲酰化反应。通过用碱处理衍生自3-羟基噻吩的烯醇化物可以以高区域选择性被O-烷基化和O-酰化。2,2-二取代噻吩-3(2 H)-one与亲核试剂进行平衡共轭加成,但无法分离所得的加合物。