Copper-Catalyzed C(sp3)–S Bond and C(sp2)–S Bond Cross-Coupling of 2-(2-Iodobenzoyl) Substituted or 2-(2-Iodobenzyl) Substituted 1,2,3,4-Tetrahydroisoquinolines with Potassium Sulfide: Synthesis of Isoquinoline-Fused 1,3-Benzothiazine Scaffolds
文摘
The sulfuration reaction of 2-(2-iodobenzoyl) substituted, or 2-(2-iodobenzyl) substituted 1,2,3,4-tetrahydroisoquinolines with potassium sulfide proceeded in the presence of copper catalysts to give tetrahydroisoquinoline-fused 1,3-benzothiazine scaffolds in moderate to appropriate yields. This protocol provided an efficient and simple strategy to construct the corresponding benzothiazine derivatives via formation of C(sp3)–S bond and C(sp2)–S bond, which the C–S bonds formed via different routes in this reaction (traditional cross-coupling reaction via the cleavage of C–I bond and oxidative cross-coupling reaction via C(sp3)–H bond functionalization).