Regioselective Synthesis of 1,2-Benzothiazine 1,1-Dioxide Derivatives by Intramolecular Heck Cyclization

Abstract

An efficient method for the synthesis of bioactive heterocycles containing 1,2-benzothiazine 1,1-dioxide derivatives via Pd-catalyzed intramolecular Heck cyclization is reported. The method offers the regioselective synthesis of highly functionalized benzosultams in 80–85% yields. The structure of benzosultam derivatives is confirmed from single crystal X-ray diffraction.