Copper-Catalyzed Aerobic Oxidative Cyclization of Ketoxime Acetates with Pyridines for the Synthesis of Imidazo[1,2-a]pyridines
作者:Zhi-Hui Ren、Zheng-Hui Guan、Mi-Na Zhao、Yukun Yi、Yao-Yu Wang
DOI:10.1055/s-0035-1561950
日期:——
copper(I)-catalyzed aerobic oxidative coupling of ketoximeacetates with simple pyridines for the synthesis of imidazo[1,2-a]pyridines has been developed. This reaction tolerates a wide range of functional groups and it affords a series of valuable imidazo[1,2-a]pyridines in high yields under mild conditions. A copper(I)-catalyzed aerobic oxidative coupling of ketoximeacetates with simple pyridines for the synthesis
摘要 已开发出铜(I)催化的酮肟肟乙酸酯与简单的吡啶的好氧氧化偶联,用于合成咪唑并[1,2- a ]吡啶。该反应可耐受各种官能团,并且在温和条件下以高收率提供了一系列有价值的咪唑并[1,2- a ]吡啶。 已开发出铜(I)催化的酮肟肟乙酸酯与简单的吡啶的好氧氧化偶联,用于合成咪唑并[1,2- a ]吡啶。该反应可耐受各种官能团,并且在温和条件下以高收率提供了一系列有价值的咪唑并[1,2- a ]吡啶。
I<sub>2</sub>–DMSO–PTSA: a simple and metal free oxidative cross coupling of imidazo[1,2-a]pyridines and methylketones
simple, highly efficient and selective oxidative cross coupling of imidazo[1,2-a]pyridine (IP) compounds (1) and methylketones (2), promoted by molecular iodine in DMSO in the presence of a catalytic amount of PTSA has been realized in a one pot reaction. This strategy has provided a general route for the synthesis of 1-aryl-2-(2-phenylimidazo[1,2-a]pyridin-3-yl)ethane-1,2-diones (3) with a new C–C bond
在催化量的PTSA存在下,由分子碘在DMSO中促进的咪唑并[1,2- a ]吡啶(IP)化合物(1)和甲基酮(2)的简单,高效且选择性的氧化交叉偶联已经被发现。一锅反应。该策略为用新的CC合成1-芳基-2-(2-苯基咪唑并[1,2 - a ]吡啶-3-基)乙烷-1,2-二酮(3)提供了一般路线。通过Kornblum氧化形成键,然后在原位形成的苯乙二醛上进行IP化合物(1)的亲核攻击。简单的反应条件,无金属催化剂和选择性的产物形成是该方案的优点。
Difluorinative-hydroxylation and C-3 functionalization (halogenation/SCN/NO) of imidazopyridine using Selectfluor as fluorine source or oxidant respectively
作者:Saradhi Kalari、Sridhar Balasubramanian、Haridas B. Rode
DOI:10.1016/j.tetlet.2021.153028
日期:2021.5
3-dihydroimidazo[1,2-a]pyridin-2-ol (3m). The Zolimidine drug successfully underwent difluorinative-hydroxylation in high yield. Interestingly, addition of the tetra-n-butyl ammonium halide or NaI or KSCN or NaNO2 in the reaction provided oxidative functionalization of imidazopyridine wherein Selectfluor acted as an oxidant. The C-3 substituted (Cl, Br, I, SCN and NO) imidazo[1,2-a]pyridines were prepared
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。
Rhodium-catalyzed annulation between 2-arylimidazo[1,2-a]pyridines and alkynes leading to pyrido[1,2-a]benzimidazole derivatives
A rhodium-catalyzed annulation between 2-arylimidazo[1,2-a]pyridines and alkynes was developed, leading to pyrido[1,2-a]benzimidazole derivatives in moderate to excellent yields.
Use of Imidazo[1,2‐
<i>a</i>
]pyridine as a Carbonyl Surrogate in a Mannich‐Like, Catalyst Free, One‐Pot Reaction
作者:Gunaganti Naresh、Naga Rajiv Lakkaniga、Anupreet Kharbanda、Wei Yan、Brendan Frett、Hong‐yu Li
DOI:10.1002/ejoc.201801430
日期:2019.1.31
developed a simple and efficient protocol to aminomethylate the C‐3 position of imidazo[1,2‐a]pyridine through a multicomponent, decarboxylation reaction involving imidazo[1,2‐a]pyridine, a secondary amine, and glyoxylic acid. The developed protocol requires mild reaction conditions and furnishes diverse imidazo[1,2‐a]pyridine analogues from commercially available starting materials.
我们开发了一种简单而有效的协议来aminomethylate咪唑并[1,2的C-3位一个通过多组分]吡啶,脱羧反应涉及咪唑并[1,2一]吡啶,仲胺,和二羟乙酸。制定的方案要求反应条件温和,并从市售起始原料中提供多种咪唑并[1,2- a ]吡啶类似物。