Copper‐Mediated One‐Pot Access to Benzo[ b ][1,4]thiazines from 2‐ N ‐Sulfonylaminoaryl Disulfides

2‐ N ‐Sulfonylaminoaryl disulfides can be converted into the corresponding benzo[ b ][1,4]thiazines in one pot when reacted with an electron‐rich alkene in the presence of a base and a substoichiometric amount of a copper salt. Depending upon the reaction conditions, and in particular the copper salt used, we observed the concurrent formation of variable amounts of the corresponding benzo[ b ][1,4]thiazine S ‐oxides that are not the result of a post‐oxidation reaction. The overall procedure can provide simple access to benzo[ b ]thiazines or thiazine S , S ‐dioxides by sequential reduction or oxidation of the crude reaction mixtures.