提出了一种在温和条件下制备咪唑并[1,2- a ]吡啶环体系的新方法。在催化的Sc(OTf)3存在下,在高温(80–140°C)下,在乙腈中用甲苯磺酸二甲基缩酮酯处理2-氨基吡啶,可得到高产率的咪唑并[1,2- a ]吡啶产物。该成环方法广泛适用于电子贫乏的2-氨基吡啶,并通过溴代酮与富电子和中性底物的反应,与经典的咪唑并[1,2- a ]吡啶环体系制备显示出互补性。讨论了过程的范围和机械方面的考虑。
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。
Sodium Salts (NaI/NaBr/NaCl) for the Halogenation of Imidazo-Fused Heterocycles
We report herein an effective method for the halogenation of imidazo-fused heterocycles using readily available sodiumsalts (NaCl/NaBr/NaI) as halogen source and K2S2O8 (or) oxone as promoter. A variety of C-3 halogenated imidazo[1,2-a]pyridines and benzo[d]imidazo[2,1-b]thiazoles were obtained in good to excellent yields. The present method of halogenation has been also extended to 2-aminopyridines
我们在此报告了一种使用容易获得的钠盐(NaCl / NaBr / NaI)作为卤素源和K 2 S 2 O 8(或)oxone作为促进剂的咪唑基稠合杂环卤化的有效方法。以良好或优异的产率获得了各种C-3卤代咪唑并[1,2- a ]吡啶和苯并[d]咪唑并[2,1- b ]噻唑。本发明的卤化方法还以中等至优异的产率扩展到2-氨基吡啶,2-氨基嘧啶,吲哚和异喹啉。
Mild and Regioselective Three‐component Heteroarylation‐Nitration of Alkenes with Imidazo[1,2‐
<i>a</i>
]pyridines and
<i>tert</i>
‐Butyl Nitrite
作者:Jie Zhang、Shentong Xie、Ping Liu、Peipei Sun
DOI:10.1002/adsc.202000078
日期:2020.5.26
An efficient and regioselective three‐component heteroarylation‐nitration of alkenes with imidazo[1,2‐a ]pyridines and tert ‐butyl nitrite has been developed. The process tolerants a variety of functional groups under mild conditions in the absence of catalysts and additives to give nitro functionalized imidazo[1,2‐a ]pyridine derivatives in moderate to good yields. The reaction is also applicable
已经开发了一种高效的区域选择性烯烃三元杂芳基硝化硝化反应,该硝化反应包括咪唑并[1,2- a ]吡啶和亚硝酸叔丁酯。在没有催化剂和添加剂的条件下,该工艺可在温和条件下耐受各种官能团,从而以中等至良好的收率得到硝基官能化的咪唑并[1,2- a ]吡啶衍生物。该反应也适用于其他一些氮杂杂环。
Palladium-catalyzed annulation of imidazo[1,2-a]pyridines with coumarins provided benzofuran fused transannulated products in good to excellent yields via a decarbonylative approach, while imidazo[1,2-a]pyridines with N-methyl indoles in the presence of palladium and base yielded conjugated imidazopyridine fused indole derivatives. Additional experiments revealed that the presence of the phenyl ring
钯催化的咪唑并[1,2- a ]吡啶与香豆素的环化反应通过脱羰方法提供了苯并呋喃稠合的环环化产物,而咪唑并[1,2- a ]吡啶与N-甲基吲哚在钯和碱产生共轭咪唑并吡啶稠合吲哚衍生物。进一步的实验表明,在咪唑并[1,2- a的 C-2 位存在苯环]吡啶对环化比烷基更重要。两种转变都遵循 Pd 催化的双 C-H 键活化的离子机制。所有的环状产品都显示出高荧光特性,并评估了它们的光物理特性。