Sulfoximines are novel privileged scaffolds that have been applied as pharmaceuticals and bioactive compound as well as ligands and chiral auxiliaries in asymmetric syntheses. As a consequence, the development of efficient methods for the synthesis of sulfoximines and their functionalizations is greatly needed. However, despite the significant advances made in the functionalization of sulfoximines, only a few examples of 1,2-benzothiazines, which are more attractive pharmacophores as a type of cyclic sulfoximine, have been reported. Herein, we have developed an efficient synthetic method for a wide range of 1,2-benzothia-zines bearing pyridyl as well as carbonyl groups by a rhodium-catalyzed domino C−H activa-tion/cyclization/elimination of alcohol process starting from S-aryl sulfoximine and pyridotriazole compounds. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (2011-0018355), 2015H1C1A1035955.