An electron-donor–acceptor complex between two intermediates enables a N–N bond cleavage cascade process to access 2,3-difunctionalized pyridines
作者:Ya-Zhou Liu、Yu Chen、Amu Wang、Zhongke Shen、Xueting Zhou、Jichao Zhang、Yinxiang Jian、Xiaofeng Ma
DOI:10.1039/d3gc04425d
日期:——
stoichiometric electron donor/acceptor is rare. Herein, we report such a process to access 2,3-difunctionalized pyridines from readily available N-aminopyridiniums (1) and activated alkenes (2) promoted by visible light. This procedure offered multi-substituted pyridines in satisfactory yields at room temperature with broad functional group tolerance. The reaction can be easily performed on a gram scale without
在不添加外源化学计量电子供体/受体的情况下,由电子供体-受体(EDA)复合物引发的化学转化很少见。在此,我们报告了在可见光促进下从容易获得的N-氨基吡啶鎓 ( 1 ) 和活化烯烃 ( 2 )中获得 2,3-双官能化吡啶的过程。该方法在室温下以令人满意的产率提供了具有广泛官能团耐受性的多取代吡啶。该反应可以很容易地在克级进行,而不会损失产率。展示了生物活性分子的修饰,包括临床药物和天然产物的衍生物。机理研究和DFT计算表明, 1和2之间的正式[3 + 2]环加成和氮杂迈克尔加成分别生成四氢吡唑并[1,5- a ]吡啶和新的吡啶鎓盐。这两种中间体形成了EDA复合物,在可见光照射下,引发了单电子转移(SET)/N-N键断裂/C-N键形成级联过程,具有高原子经济性。