Copper-Catalyzed Oxidative Coupling of β-Keto Esters with <i>N</i>-Methylamides for the Synthesis of Symmetrical 2,3,5,6-Tetrasubstituted Pyridines
作者:Yizhe Yan、Hongyi Li、Zheng Li、Bin Niu、Miaomiao Shi、Yanqi Liu
DOI:10.1021/acs.joc.7b01516
日期:2017.8.18
copper-catalyzed oxidative formal [2+2+1+1] cycloaddition for the synthesis of symmetrical tetrasubstituted pyridines was first demonstrated. The reaction is involved in a domino cross-dehydrogenative coupling (CDC) of β-keto esters and N-methylamides, the C–N bond cleavage, the Michael addition, and a condensation and oxidative aromatization process. Multiple C–C and C–N bonds were constructed in one pot via the
首次证明了用于对称四取代吡啶合成的铜催化的氧化式[2 + 2 + 1 + 1]环加成反应。该反应涉及β-酮酯和N-甲基酰胺的多米诺交叉脱氢偶联(CDC),C–N键断裂,迈克尔加成以及缩合和氧化芳构化过程。一锅中通过N-甲基酰胺的C-H和C-N裂解构建了多个C-C和C-N键,它们被用作吡啶的碳源。初步的机理研究表明,N-甲基酰胺的C(sp3)–H键断裂是决定速率的步骤。