Rh(III)-catalysed C-H/C-H cross-coupling of S -aryl sulfoximines with thiophenes: facile access to [1]benzothieno[3,2- b ][1]benzothiophene (BTBT) and benzothiazines.

Reported herein is rhodium-catalysed oxidative C-H/C-H cross-coupling of S -aryl sulfoximines with thiophenes via a chelation-assisted strategy, which provides an efficient approach for the construction of [1]benzothieno[3,2- b ][1]benzothiophene (BTBT) and benzothiazine skeletons from easily available substrates. This protocol exhibits a good compatibility with halogen substituents, thus paving the way for further transformation to prepare various organic functional molecules. The resulting benzothiazine derivative shows a deep blue emission with Commission Internationale de 'Eclairage (CIE) coordinates of (0.15, 0.04), a high quantum yield, and a delayed fluorescence lifetime.