2-(2'-羟基苯基)咪唑并[1,2- a ]吡啶(HPIP,1)及其衍生物的合成,并对其荧光性质进行了研究。尽管所有化合物均显示出微弱的双重发射(Φ≈0.01),这与流体溶液中的正常和激发态分子内质子转移(ESIPT)荧光有关,但它们通常在化合物溶液中均显示出有效的ESIPT荧光(Φ最高可达0.6)。聚合物基质。给电子基团和吸电子基团引入苯环分别导致ESIPT荧光发射带发生蓝移和红移。另一方面,将这些基团引入咪唑并吡啶部分导致荧光向相反方向移动。分子内质子转移(IPT)状态的从头算量子化学计算的结果与ESIPT荧光能量非常吻合。计算出的最高占据分子轨道(HOMO)和最低未占据分子轨道(LUMO)能级相对于Hammett取代基常数(σ)的图显示了具有不同斜率的良好线性,这可以合理化取代基的作用及其在聚合物上的位置IPT状态。因此,我们开发了一系列HPIP作为新的ESIPT荧光化合物,并证明
Electrochemically initiated intermolecular C–N formation/cyclization of ketones with 2-aminopyridines: an efficient method for the synthesis of imidazo[1,2-<i>a</i>]pyridines
Electrochemical intermolecular C–N formation/cyclization of ketones with 2-aminopyridines using catalytic hydriodic acid as the redox mediator was developed, providing imidazo[1,2-a]pyridines under more environmentally benign conditions. The reaction proceeds in a simple undivided cell, using low toxic ethanol as the solvent, without external oxidants, and exhibits high atom economy. A variety of ketones
开发了使用催化氢碘酸作为氧化还原介体的2-氨基吡啶与酮的电化学分子间C–N形成/环化反应,在更环境友好的条件下提供了咪唑并[1,2- a ]吡啶。该反应在一个简单的,没有分裂的细胞中进行,使用低毒的乙醇作为溶剂,没有外部氧化剂,并且具有很高的原子经济性。该反应适合各种酮,包括苯乙酮,未取代的和烷基酮,以中等至极好的收率提供相应的产物。在标准条件下,也可以实现三组分串联反应,实现C–N,C–S / C–Se键的形成。
Generation of thioethers via direct C–H functionalization with sodium benzenesulfinate as a sulfur source
A novel ammonium iodide-induced sulfenylation method of flavones, indole and arylimidazo[1,2-a]pyridines using stable and odorless sodium benzenesulfinates as sulfur sources was developed, generating regioselective derivatives in good yields.
Iodine–ammonium acetate promoted reaction between 2-aminopyridine and aryl methyl ketones: a novel approach towards the synthesis of 2-arylimidazo[1,2-a]pyridines
作者:Dilpreet Kour、Rajni Khajuria、Kamal K. Kapoor
DOI:10.1016/j.tetlet.2016.08.058
日期:2016.10
I2–NH4OAc was found to be an efficient system for the metal-free synthesis of diversely substituted imidazo[1,2-a]pyridines 3a–r from 2-aminopyridine 1 and aryl methyl ketones 2a–r in one pot. 2-Arylimidazo[1,2-a]pyridines 3a–r were obtained in good to excellent yields via in situ generation of an Ortoleva–King intermediate (pyridinium iodide), followed by NH4OAc-assisted cyclization.
发现I 2 -NH 4 OAc是一种有效的系统,可在一锅中由2-氨基吡啶1和芳基甲基酮2a - r进行无取代合成咪唑并[1,2- a ]吡啶3a - r的无金属合成。通过原位生成Ortoleva-King中间体(碘化吡啶),然后进行NH 4 OAc辅助环化,可以很好地获得2-ArylimidazOAzo [1,2- a ]吡啶3a – r。
Transition-Metal-Free Lactonization of sp<sup>2</sup> C–H Bonds with CO<sub>2</sub>
The transition-metal-free lactonization of heteroaryl and alkenyl C–H bonds with carbon dioxide is reported to synthesize important coumarin derivatives in moderate to excellent yields. These redox-neutral reactions feature a broad substrate scope, good functional group tolerance, facile scalability, and easy product derivatization.
three‐component synthetic protocols have been developed by using imidazo[1,2‐a]pyridine, inorganic, odorless S8 and alcohols or arylboronic acids as reactants to make alkylthio‐/arylthio‐substituted imidazo[1,2‐a]pyridine derivatives via C(sp2)–H functionalization. The reactions proceeded with high efficiency and broad functional group tolerance, affording the products regioselectively and in good yields
磺酰化是在有机合成中生成CS键的重要转变。在此,通过使用咪唑并[1,2- a ]吡啶,无机,无味的S 8和醇或芳基硼酸作为反应物,开发了两种三组分合成方案,以制备烷硫基/芳硫基取代的咪唑并[1,2- a]。通过C(sp 2)–H官能团合成]吡啶衍生物。反应以高效率和宽泛的官能团耐受性进行,提供了区域选择性的产物并具有良好的收率。