在水性介质中,已经开发了一种通过使用Selectfluor作为氟源通过咪唑并吡啶的脱芳香基二官能化来进行二氟羟基化的有效途径。该反应通过离子进行,随后通过自由基途径进行。产物以纯净形式获得,无需柱纯化。该方法已成功用于3,3-二氟-2-(4-氟苯基)-2,3-二氢咪唑并[1,2 - a ]吡啶-2-醇(3m)的克级生产。唑来idine啶药物成功地以高收率进行了二氟羟基化反应。有趣的是,加入四正丁基卤化铵或NaI或KSCN或NaNO 2在该反应中,咪唑并吡啶具有氧化功能,其中Selectfluor起氧化剂的作用。以良好的产率制备了C-3取代的(Cl,Br,I,SCN和NO)咪唑并[1,2- a ]吡啶。这两个重要的反应提供了宽泛的官能团耐受性,无金属/无碱和绿色方法。
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。
Pd-catalyzed annulation of imidazo[1,2-<i>a</i>]pyridines with coumarins and indoles: synthesis of benzofuran and indole fused heterocycles
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。
Base-Promoted Transition-Metal-Free Arylation of Imidazo-Fused Heterocycles with Diaryliodonium Salts
The arylation of imidazo[1,2‐a]pyridine and benzo[d]imidazo[2,1‐b]thiazoles by using diaryliodonium salts has been developed. Potassium tert‐butoxide was used to promote this transition‐metal‐free reaction, which afforded the corresponding products in good to excellent yields.
咪唑的芳基化[1,2一]吡啶和苯并[ d ]咪唑并[2,1- b ]通过使用二芳基碘盐已经开发噻唑。钾叔丁醇是用来促进此过渡金属无反应,得到相应的产品以良好至优异的产量。
Visible-light-induced regioselective sulfenylation of imidazopyridines with thiols under transition metal-free conditions
作者:Rajjakfur Rahaman、Shivasish Das、Pranjit Barman
DOI:10.1039/c7gc02906c
日期:——
A metal-freevisible-light-promoted regioselective C-3 sulfenylation of imidazo[1,2-a]pyridines and indoles using thiols has been developed via C(sp2)–H functionalization. This method provides direct access to a wide range of structurally diverse 3-sulfenylimidazopyridines of biological interest. The operational simplicity, eco-energy source, high atom efficiency, and the use of green solvents under
通过C(sp 2)–H官能团开发了一种无金属的可见光促进的咪唑并[1,2- a ]吡啶和吲哚类吲哚类化合物的C-3区域选择性C-3亚磺酰基。该方法提供了直接接触生物感兴趣的结构上广泛的3-亚磺酰基咪唑并吡啶的途径。操作简便,生态能源,高原子效率以及在环境条件下使用绿色溶剂是该方法的一些吸引人的特征。