Copper(I) Iodide/Boron Trifluoride Etherate-Cocatalyzed Aerobic Dehydrogenative Reactions Applied in the Synthesis of Substituted Heteroaromatic Imidazo[1,2-<i>a</i>]pyridines
作者:Zhong-Jian Cai、Shun-Yi Wang、Shun-Jun Ji
DOI:10.1002/adsc.201300333
日期:2013.9.16
dehydrogenation coupling reactions, similar transforms initiated by copper/oxygen have attracted more and more attention. We have investigated a novel construction of heteroaromatic imidazo[1,2‐a]pyridines through copper(I) iodide/boron trifluoride etherate/oxygen‐mediated dehydrogenative reactions of aryl alkyl or alkyl alkyl ketones with 2‐aminopyridines. Four hydrogen atoms are removed and two new CN bonds
与众所周知的钯催化的氧化脱氢偶联反应相比,由铜/氧引发的类似转化越来越受到关注。我们研究了通过芳基烷基或烷基烷基酮与2-氨基吡啶的碘化亚铜(I)/三氟化硼醚化物/氧介导的脱氢反应,研究杂芳族咪唑并[1,2- a ]吡啶的新型结构。通过亚胺的形成和氧化性C(sp 3)H官能化一步除去四个氢原子并形成两个新的CN键。
Novel one step synthesis of imidazo[1,2-a]pyridines and Zolimidine via iron/iodine-catalyzed Ortoleva-King type protocol
作者:Sankuviruthiyil Mohanan Ujwaldev、K.R. Rohit、Nissy Ann Harry、Gopinathan Anilkumar
DOI:10.1016/j.tetlet.2019.150950
日期:2019.8
Imidazo[1,2-a]pyridines form versatile scaffolds in pharmaceutical industry arising from their diverse biological activities. The synthesis of these molecules thus has been of great interest and resulted in the development of a large number of new methodologies. Herein we describe the first iron-catalyzed Ortoleva-King type protocol towards the synthesis of these fused heterocycliccompounds. This
咪唑并[1,2- a ]吡啶因其多种生物活性而在制药工业中形成多功能支架。因此,这些分子的合成引起了极大的兴趣,并导致了许多新方法的发展。在这里,我们描述了第一个铁催化的Ortoleva-King型协议,以合成这些稠合的杂环化合物。该方法采用廉价且容易获得的FeCl 3 ·6H 2 O和分子碘作为催化体系。该过程已被基板范围与各种芳族酮和2-氨基吡啶,得到不同的咪唑并延伸[1,2被很好探索一个吡啶衍生物的产率中等至良好。该方案的成功应用还通过直接一步合成胃保护药物Zolimidine得到了证明。
Photoredox-Cobaloxime Catalysis for Selective Oxidative Dehydrogenative [4+2] Annulation of Imidazo-Fused Heterocycles with Alkenes
A selective oxidative [4+2] annulation of alkenes with imidazo-fused heterocycles has been developed by using the synergistic combination of photoredox and cobaloxime catalysts. It allows facile access to various imidazole-fused polyaromatic scaffolds accompanied by H2 evolution. This protocol features high regioselectivity as well as a broad substrate scope. Detailed mechanistic studies indicate that
通过使用光氧化还原和钴肟催化剂的协同组合,开发了烯烃与咪唑稠合杂环的选择性氧化[4+2]环化。它允许轻松获得各种咪唑稠合的聚芳族支架,并伴随 H 2 的演化。该方案具有高区域选择性和广泛的底物范围。详细的机理研究表明,该催化系统促进的电子/氢转移过程的两倍实现了咪唑稠合杂环与烯烃的环π延伸。