Chiral 1,2-Benzothiazine Synthesis via Rhodium-Catalyzed Asymmetric C–H Activation/Cyclization with Chiral Carboxylic Amides

Chiral sulfur-containing fused heterocycles are privileged scaffolds in medicinal chemistry. Expanding the catalytic repertoire for the asymmetric synthesis of bioactive sulfur heterocycles via C–H activation remains a persistent pursuit. We report herein an efficient annulation of sulfoximines with diarylacetylenes catalyzed by an achiral Cp*Rh(III) complex, where stereocontrol is governed by a chiral carboxylic amide additive. This protocol provides access to a diverse array of enantioenriched 1,2-benzothiazines in excellent yields (up to 99%) and enantioselectivities (up to 99% ee).