Synthesis and properties of Thieno[3,2-f]isoquinolines and Benzothieno[3,2-f]isoquinolines

Abstract

A variety of thieno[3,2-f]isoquinolines were prepared by combination of Pd catalysed cross-coupling reactions with Brønsted acid mediated cycloisomerisations. The reactions tolerate various functional groups and proceed with high selectivity. In addition, benzothieno[3,2-f]isoquinolines were prepared which represent a new heterocyclic core structure. The optical properties of selected compounds were studied by experimental and theoretical methods. Emission solvatochromism, characteristic of intramolecular charge transfer was observed for one of the compounds with a push-pull structure.