Easy Photochemical Preparation of 2-Dimethylaminophenylfurans, -Pyrroles and -Thiophenes
作者:Benedetta Guizzardi、Mariella Mella、Maurizio Fagnoni、Angelo Albini
DOI:10.1016/s0040-4020(00)00909-1
日期:2000.11
2-(4-N,N-dimethylaminophenyl) heterocycles are smoothly obtained from the photolysis of 4-chloro-N,N-dimethylaniline in acetonitrile in the presence of furan, pyrrole, thiophene and some of their methyl derivatives bearing a free α-position. With 2,5-dimethyl heterocycles the arylation occurs with equal efficiency in the β position. In the case of furan, when the irradiation is carried out in methanol
2-(4- Ñ,Ñ -dimethylaminophenyl)杂环平稳地从4-氯的光解得到Ñ,Ñ二甲基苯胺在乙腈在呋喃,吡咯的存在,噻吩以及它们的一些甲基衍生物的带有游离α-位置。对于2,5-二甲基杂环,芳基化反应在β位置的效率相同。在呋喃的情况下,当在甲醇中进行辐照时,顺式/反式得到2-芳基-5-甲氧基-2,5-二氢加合物。该反应被合理化为涉及苯胺三重态下的C–Cl键的杂合裂解。由此形成的三重芳基阳离子的中间体解释了所观察到的该方法的高区域选择性和化学选择性。