Diverse alcohol-tethered 5-iodotriazoles, readily accessible by a modified protocol of Cu-catalyzed (3+2)-cycloaddition, were utilized as precursors of the target fused heterocycles. The intramolecular C–O coupling proceeded efficiently under base-mediated transition-metal-free conditions, furnishing cyclization products in yields up to 96%. Suppression of the competing reductive cleavage of the C–I
一种方便的方法来组装
1,2,3-三唑融合的 4H-3,1-苯并恶嗪。多种醇系 5-
碘三唑,可通过 Cu 催化 (3+2)-环加成的改进方案轻松获得,被用作目标稠合杂环的前体。分子内 C-O 偶联在无碱介导的过渡
金属条件下有效进行,环化产物的产率高达 96%。通过在 100 °C 的
乙腈中使用 Na2CO3 来抑制 C-I 键的竞争性还原裂解。这种实用且具有成本效益的程序具有广泛的底物范围和宝贵的官能团耐受性。