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 CÀ N coupling reaction sequence. The results suggest an interrupted domino process involving an iodinated triazole as a key intermediate.

A variety of 3-amino-substituted benzothiadiazine oxides were synthesised in a single-step by applying a palladium-catalysed cascade reaction of 2-azido sulfoximines with isonitriles. The desired heterocycles were observed in good to...