Catalytic reductive cyclization of 2-nitrobiphenyls using phenyl formate as CO surrogate: A robust synthesis of 9H-carbazoles
作者:Doaa R. Ramadan、Francesco Ferretti、Fabio Ragaini
DOI:10.1016/j.jcat.2022.03.024
日期:2022.5
A palladium/phenanthroline catalyzed reductive cyclization of o-nitrobiphenyls to 9H-carbazoles operated by in situ released CO is described. In the present method, the presence of phenyl formate is essential to avoid the use of high-pressure equipment and allows to perform the reaction in a single thick-walled glass tube. The identity of the base, which catalyzes the formate decomposition, is crucial
描述了通过原位释放的 CO操作的钯/菲咯啉催化的邻硝基联苯还原环化为 9 H-咔唑。在本方法中,甲酸苯酯的存在对于避免使用高压设备是必不可少的,并且允许在单个厚壁玻璃管中进行反应。催化甲酸盐分解的碱的特性对反应的选择性至关重要。催化剂的稳定性受氯阴离子存在的影响。咔唑产率通常高于之前报道的使用加压 CO 的产率。优化的催化系统具有出色的稳定性和耐湿性和耐空气性,可以在低催化剂负载下进行反应。