Dienophilicity of Imidazole in Inverse Electron Demand Diels−Alder Reactions. 4. Intermolecular Reactions with 1,2,4-Triazines
作者:Brian R. Lahue、Zhao-Kui Wan、John K. Snyder
DOI:10.1021/jo030049y
日期:2003.5.1
cycloadditions of 2-substituted imidazoles with various 1,2,4-triazines produced both imidazo[4,5-c]pyridines (3-deazapurines) and pyrido[3,2-d]pyrimid-4-ones (8-deazapteridines). The product distribution was controlled by reactant substituents and influenced by reaction temperature. A regioselective method for the preparation of 6-unsubstituted 1,2,4-triazines was also developed. By using this route to 8-deazapteridines
2-取代的咪唑与各种1,2,4-三嗪的分子间逆电子需求环加成反应既产生了咪唑并[4,5-c]吡啶(3-deazapurines),也产生了吡啶并[3,2-d]嘧啶-4-酮( 8-脱氮庚啶)。产物分布由反应物取代基控制,并受反应温度影响。还开发了一种区域选择性的方法来制备6-未取代的1,2,4-三嗪。通过使用该途径制备8-脱氮庚啶,制备了新的8-脱氮叶酸酯类似物。