Dienophilicity of imidazole in inverse electron demand Diels–Alder reactions: cycloadditions with 1,2,4,5-tetrazines and the structure of zarzissine
作者:Zhao-Kui Wan、Grace H.C. Woo、John K. Snyder
DOI:10.1016/s0040-4020(01)00476-8
日期:2001.6
The inverse electron demand cycloadditions of 2-substituted imidazoles with dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate produced imidazo[4,5-d]pyridazines in good yields. This chemistry was applied to the synthesis of 2-amino-1H-imidazo[4,5-d]pyridazine (1), the structure reported for zarzissine, a cytotoxic marine alkaloid. Differences in the 1H- and 13C NMR spectra of 1 with those reported for zarzissine
2-取代的咪唑与1,2,4,5-四嗪-3,6-二羧酸二甲酯的反电子需环加成反应可得到高产率的咪唑并[4,5- d ]哒嗪。该化学方法被用于2-氨基-1 H-咪唑并[4,5- d ]哒嗪(1)的合成,该结构报道了具有细胞毒性的海洋生物碱zarzissine的结构。在差异1 H-和13的C NMR光谱1与文献报道为zarzissine必要的结构修改,然后zarzissine被认为是相应的2-氨基-1 ħ -咪唑并[4,5- b ]吡嗪(2),随后由母体杂环合成。