An efficient one-pot two catalyst system in the construction of 2-substituted benzimidazoles: synthesis of benzimidazo[1,2-c]quinazolines
作者:Cristina Cimarelli、Matteo Di Nicola、Simone Diomedi、Riccardo Giovannini、Dieter Hamprecht、Roberta Properzi、Federico Sorana、Enrico Marcantoni
DOI:10.1039/c5ob01777g
日期:——
cyclo-dehydrogenation of aniline Schiff's bases, generated in situ from the condensation of 1,2-phenylenediamine and aldehydes, followed by the oxidation with iodine, which works as a hydrogen sponge. Mild reaction conditions, good to excellent yields, and clean reactions make the procedure a useful contribution to the synthesis of biologically active fused heterocycles containing benzimidazoquinazolines.
苯并咪唑核心是大量天然产物和具有药理活性的小分子的共同组成部分。新型苯并咪唑衍生物的合成仍然是医学研究的主要重点。在继续努力实现有机转化的Ce(III)催化剂方面,我们首次观察到碘离子和铜阳离子在选择性形成原型2取代的苯并咪唑类化合物中活化CeCl 3 ·7H 2 O的活性。一锅法CeCl 3 ·7H 2 O–CuI催化系统程序包括原位生成的苯胺席夫碱的环脱氢1,2-苯二胺和醛的缩合反应,然后用碘氧化,碘作为氢海绵。温和的反应条件,良好或优异的收率以及干净的反应使该方法对合成含有苯并咪唑并喹唑啉类的生物活性稠合杂环作出了有益的贡献。