A Copper‐Catalyzed Interrupted Domino Reaction for the Synthesis of Fused Triazolyl Benzothiadiazine‐1‐oxides.

Copper(I)‐catalyzed domino reactions of 2‐azido sulfoximines with 1‐iodoalkynes yield fused triazolyl‐containing benzothiadiazine‐1‐oxides. The protocol features the synthesis of two fused heterocyclic rings in one step with good to excellent yields and a broad functional group tolerance. Detailed mechanistic investigations indicate that a copper π‐complex initiates a cycloaddition and oxidative C−N coupling reaction sequence. The results suggest an interrupted domino process involving an iodinated triazole as a key intermediate. [ABSTRACT FROM AUTHOR]