Cycloisomerization – a straightforward way to benzo[h]quinolines and benzo[c]acridines
作者:Aleksandr N. Shestakov、Alena S. Pankova、Mikhail A. Kuznetsov
DOI:10.1007/s10593-017-2179-5
日期:2017.10
Cycloisomerization of 3-alkynyl-2-arylpyridines and quinolines offers a straightforward approach to benzo[h]quinolines and benzo[c]-acridines. Substituent at the triple bond governs a choice between transition metal or Brønsted acidcatalysis. A direct electrophilic activation by trifluoromethanesulfonic acid induces an almost quantitative cyclization of the o-aryl(phenylethynyl) fragment. PtCl2 efficiently
3-炔基-2-芳基吡啶和喹啉的环异构化为苯并[ h ]喹啉和苯并[ c ] -ac啶提供了一种直接的方法。在三键处的取代基决定过渡金属催化或布朗斯台德酸催化之间的选择。三氟甲磺酸的直接亲电子活化引起邻-芳基(苯基乙炔基)片段的几乎定量环化。PtCl 2有效催化2-芳基-3-乙炔基戊烯的环化。
Synthesis of pyrrolo[3,4-c]quinolines by 1,5-electrocyclisation of non-stabilised azomethine ylides
A new route to the pyrrolo[3,4-c]quinoline ring system has been developed via the 1,5-dipolar electrocyclisation reactions of azomethine ylides derived from easily available 3-formylquinoline derivatives. The intermediacy of azomethine ylides was shown by the trapping of the proposed dipoles with N-phenylmaleimide.
通过衍生自易得的3-甲酰基喹啉衍生物的甲亚胺基团的1,5-偶极电环化反应,已经开发了一条通往吡咯并[3,4- c ]喹啉环系统的新途径。通过用N-苯基马来酰亚胺捕获拟议的偶极子,表明了甲亚胺烷基化物的中间体。