Cu-Catalyzed Three-Component Cascade Synthesis of 1,3-Benzothiazines from <i>ortho</i>-Aminohydrazones and Bromodifluoroacetamides
Changjiang Yu, Fumei Ke, Jianke Su, Xingxing Ma, Xin Li, Qiuling Song
Abstract
An efficient and convenient synthesis of benzo[d][1,3]thiazine has been developed by employing a copper-catalyzed transformation of readily available ketone-derived hydrazones with elemental sulfur and bromodifluoroalkylative reagents. The strategy involves an S8-catalyzed selective triple-cleavage of bromodifluoroacetamides, which acts as a C1 synthon at the 2-position of benzo[d][1,3]thiazine. A mechanism proceeding through a Cu–carbene intermediate is proposed for the C–S bond formation.
Topics & Concepts
ChemistrySynthonThiazineCatalysisReagentCarbeneCleavage (geology)KetoneCombinatorial chemistryBond cleavageSulfurCascadeMedicinal chemistryStereochemistryOrganic chemistryChromatographyEngineeringFracture (geology)Geotechnical engineeringSynthesis and Catalytic ReactionsSulfur-Based Synthesis TechniquesCyclopropane Reaction Mechanisms