Functionalization of thiazolo[5,4-c]isoquinolines through Suzuki–Miyaura coupling

Abstract

The functionalization of halogenated thiazolo[5,4-c]isoquinolines (TzIQ) through the Suzuki–Miyaura reaction with arylboronic acids is reported here for the first time. Three TzIQ derivatives bearing only chlorine atoms or chlorine and bromine atoms were used in this work. The results unequivocally confirm the impact of different halogen atoms, and their positions on the TzIQ core, on the outcome of these reactions. Excellent chemoselectivity was observed for the TzIQ bearing chlorine and bromine atoms. The new TzIQ derivatives were fully characterized by NMR and MS techniques and the structure of the TzIQ 9b was also confirmed by single-crystal X-ray diffraction. The absorption and emissive properties of the new compounds indicate that some of them may be useful in applications requiring strong luminescence and large Stokes shifts.