在这项工作中,合成了一系列苯甲酰溴衍生物,并用作合成取代的咪唑并[1,2- a ]吡啶的关键中间体。首先,在微波辐射的辅助下,通过苯乙酮的溴化反应获得苯甲酰溴分子,在15分钟的反应中获得产物4a-v,产率在50%至99%之间。随后,这些分子与2-氨基吡啶共轭,产生了咪唑并[1,2- a ]吡啶衍生物(7a-v)在60秒的反应中产率为24%至99%。相对于通过更繁琐的方法(如热辅助和机械辅助路线)获得的产量,确定了更高的产量。根据取代基的性质,在紫外线激发下观察到电磁光谱的紫色和蓝色区域中的强烈发光发射。这种对环境友好的方法有望构成一类重要的有机化合物,用于开发生物标志物,光化学传感器和医学应用。
Iodine-catalyzed regioselective sulfenylation of imidazoheterocycles in PEG<sub>400</sub>
作者:Marie-Aude Hiebel、Sabine Berteina-Raboin
DOI:10.1039/c4gc01462f
日期:——
An iodine-catalyzedsulfenylation of imidazo[1,2-a]-pyridines, -pyrimidines, and [1,2-b]pyridazines is herein described with various thiophenols using hydrogen peroxide as an oxidizing agent in PEG400. The method enabled the formation of 3-arylthioimidazoheterocycles in moderate to excellent yields under metal-free conditions. Several functional groups were well tolerated under our optimized conditions
本文描述了咪唑并[1,2- a ]-吡啶,-嘧啶和[1,2- b ]哒嗪的碘催化的亚磺酰基化,其中使用过氧化氢作为氧化剂在PEG 400中与各种硫酚一起使用。该方法能够在无金属条件下以中等至优异的产率形成3-芳基硫代咪唑并杂环。在我们优化的条件下,几个官能团的耐受性良好。
Iodine-Mediated Difunctionalization of Imidazopyridines with Sodium Sulfinates: Synthesis of Sulfones and Sulfides
作者:Yu-Jing Guo、Shuai Lu、Lu-Lu Tian、En-Ling Huang、Xin-Qi Hao、Xinju Zhu、Tian Shao、Mao-Ping Song
DOI:10.1021/acs.joc.7b02734
日期:2018.1.5
Novel iodine-induced sulfonylation and sulfenylation of imidazopyridines have been described using sodium sulfinates as the sulfur source. This strategy enables highly selective difunctionalization of imidazo[1,2-a]pyridine to access sulfones and sulfides in good yields. A wide range of substrates and functional groups were well-tolerated under optimized conditions. Moreover, control experiments have
已经描述了使用亚磺酸钠作为硫源的新的碘诱导的咪唑并吡啶的磺酰化和亚磺酰化。该策略能够使咪唑并[1,2- a ]吡啶高度选择性地进行双官能化,从而以高收率获得砜和硫化物。在最佳条件下,各种底物和官能团均具有良好的耐受性。此外,已经进行了对照实验,表明了反应机理中涉及的自由基途径。
Metal-Free Regioselective Alkylation of Imidazo[1,2-a]pyridines with N-Hydroxyphthalimide Esters under Organic Photoredox Catalysis
A visible-light-induced direct C–H alkylation of imidazo[1,2-a]pyridines has been developed. It proceeds at room temperature by employing inexpensive Eosin Y as a photocatalyst and alkyl N-hydroxyphthalimide (NHP) esters as alkylationreagents. A variety of NHP esters derived from aliphatic carboxylicacids (primary, secondary, and tertiary) were tolerated in this protocol, giving the corresponding
hydroxymethylation or methylenation of imidazo-heteroarenes with formaldehyde, generated in situ via the oxidative cleavage of ethylene glycol or glycerol (renewable reagents) through the Malaprade reaction. In the presence of ethylene glycol, a series of 3-hydroxymethyl-imidazo-heteroarenes was obtained in good to excellent yields. These compounds are important intermediates to access pharmaceutical drugs
在此,我们报告了一种 KIO 4介导的、可持续的和化学选择性的方法,用于一锅 C(sp 2 )-H 键羟甲基化或咪唑杂芳烃与甲醛的甲基化,通过乙二醇或甘油的氧化裂解原位生成。可再生试剂)通过马拉普拉德反应。在乙二醇的存在下,以良好到极好的收率获得了一系列 3-羟甲基-咪唑并杂芳烃。这些化合物是获取药物(例如唑吡坦)的重要中间体。此外,通过使用甘油,双(咪唑并[1,2 - a ]吡啶-3-基)甲烷衍生物以良好到优异的产率被选择性地获得。
Palladium-catalyzed oxidative C–H/C–H cross-coupling of imidazopyridines with azoles
An effective palladium-catalyzed oxidative C–H/C–H cross-coupling of imidazopyridines with azoles using air as the oxidant has been developed. This protocol provides a straightforward and operationally simple method for the synthesis of 3-azolyl-imidazopyridines in moderate to good yields and with good functional group tolerance. The biological evaluation revealed that the newly synthesized compounds