Heterogeneously copper-catalyzed oxidative synthesis of imidazo[1,2-a]pyridines using 2-aminopyridines and ketones under ligand- and additive-free conditions
作者:Xu Meng、Yanmin Wang、Chaoying Yu、Peiqing Zhao
DOI:10.1039/c4ra03299c
日期:——
and mild heterogeneously CuCl2/nano-TiO2-catalyzed aerobic synthesis of imidazo[1,2-a]pyridinesfrom 2-aminopyridines and ketones has been developed using air as the oxidant in the absence of any ligands and additives. This strategy was compatible with a large range of substrates, including unactivated arylketones and unsaturated ketones and went through the C–H bond functionalization mechanism instead
利用空气作为氧化剂,在不存在任何配体和添加剂的情况下,开发了一种高效,温和的,异质性的CuCl 2 /纳米TiO 2催化的由2-氨基吡啶和酮类咪唑并[1,2- a ]吡啶的好氧合成方法。这个策略是具有大范围的底物相容的,包括未活化的芳基酮和不饱和酮,并通过C-H键的官能机构去的,而不是我- -assisted Ortoleva景反应以提供相应的咪唑并[1,2一以较低的催化剂负载量(0.8摩尔%)获得高产率的对吡啶。而且,该非均相催化剂可以成功地用于克规模的合成中并且可以多次重复使用而不会显着降低催化活性。