研究了分子内亲核芳族取代反应(称为Truce-Smiles重排)中底物中强电子吸收取代基对芳环活化的要求。初步的力学实验支持S N Ar机理,包括原位形成的Meisenheimer中间体的1 H和13 C NMR光谱。通常观察到重排对于具有强吸电子取代基(例如硝基,氰基和苯甲酰基官能团)的底物是成功的,但对于具有多个弱吸电子取代基(例如氯和溴官能团)的底物也是如此组。这些结果提供进一步的澄清的芳基取代基在这种类型的S的影响Ñ的Ar反应。另外,该调查还揭示了某些底物进行的一些串联环化和/或消除反应。
Polycyclic N-Heterocyclic Compounds. Part 63: Improved Synthesis of 5-Amino-1,2-dihydrofuro[2,3-c]isoquinolines via Truce-Smiles Rearrangement and Subsequent Formation to Furo[2,3-c]isoquinoline
An improved synthesis of 5-amino-1,2-dihydrofuro[2,3-c]isoquinoline has been achieved using a slight modification of reaction conditions for the Truce-Smiles rearrangement. Acid treatment of the obtained 5-amino-1,2-dihydrofuro[2,3-c]isoquinolines gave unexpected ring-opened spiro ring compounds. The previously unreported parent compound, furo[2,3-c]isoquinoline, was also synthesized.
An efficient methodology for the synthesis of thieno[2,3-c][2,7] naphthyridine (6), thieno[2,3-c]isoquinoline (11), furo[2,3-c]isoquinoline (14), [1]benzothieno[3,2-d]thieno[2,3-b]pyridine (21), and [1]benzothieno[3,2-d]furo-2,3-b]pyridine (26) skeletons from 4-[o-cyanoarylthio(or oxy)]butyronitriles with base via Smiles type rearrangement reaction followed by the cyclization is described.