Game of Isomers: Bifurcation in the Catalytic Formation of Bis[1]benzothieno[1,4]thiazines with Conformation-Dependent Electronic Properties

Two regioisomers of bis[1]­benzothieno­[1,4]­thiazine are unexpectedly obtained by tuning the catalytic conditions of the intermolecular–intramolecular Buchwald–Hartwig amination. Mechanistic insights and evidence of intermediates support a conclusive mechanistic rationale. Furthermore, a computationally based study on the influence of conformational aspects on the HOMO energy level of anellated 1,4-thiazine paves the way to enhance the electronic properties, thus successfully achieving higher luminescent and easier oxidizable syn–syn bis[1]­benzothieno­[1,4]­thiazines.