Photoredox halogenation of quinolones: the dual role of halo-fluorescein dyes
作者:Ritu、Sharvan Kumar、Parul Chauhan、Nidhi Jain
DOI:10.1039/d1ob00538c
日期:——
An unprecedented visible light mediated regioselective C-3 halogenation of quinolones was achieved using halo-fluorescein dyes as a halogen source and air as an oxidant. This reaction has broad substrate scope and gives 3-halo quinolone derivatives.
Herein, a novel and efficient intermolecular cyclization of 2-aminoacetophenones with aldehydes was developed for the synthesis of 2-aryl-4-quinolones through C–C and C–N bond formation. Mild conditions, good functional group tolerance, and substrates without prefunctionalization make this protocol practical, and this strategy will stimulate keen interest in fields of chemistry and biology.
This work describes an effective C3–H halogenation of quinoline-4(1H)-ones under electrochemical conditions, in which potassium halides serve as both halogenating agents and electrolytes. The protocol provides expedient access to different halogenated quinoline-4(1H)-ones with unique regioselectivity, broad substrate scope, and gram-scale synthesis employing convenient, environmentally friendly electrolysis
这项工作描述了在电化学条件下喹啉-4(1 H )-酮的有效 C3-H 卤化,其中卤化钾既充当卤化剂又充当电解质。该方案提供了在不分开的电池中方便地获得不同的卤代喹啉-4(1 H )-酮的方法,这些卤代喹啉-4(1 H)-酮具有独特的区域选择性、广泛的底物范围以及采用方便、环保的电解进行的克级合成。机理研究表明,卤素自由基可以促进喹诺酮类药物中N-H键的活化。
Antiviral activity evaluation and action mechanism of myricetin derivatives containing thioether quinoline moiety
A variety of myricetin derivatives containing thioether quinoline moiety were designed and synthesized. Their structures of title compounds were determined by 1H NMR, 13C NMR, 19F NMR, and HRMS. Single-crystal X-ray diffraction experiments were carried out with B4. Antiviral activity indicated that some of the target compounds exhibited remarkable anti-tobacco mosaic virus (TMV) activity. In particular, compound B6 possessed significant activity. The half maximal effective concentration (EC50) value of the curative activity of compound B6 was 169.0 μg/mL, which was superior to the control agent ningnanmycin (227.2 μg/mL). Meanwhile, the EC50 value of the protective activity of compound B6 was 86.5 μg/mL, which was better than ningnanmycin (179.2 μg/mL). Microscale thermophoresis (MST) indicated that compound B6 had a strong binding capability to the tobacco mosaic virus coat protein (TMV-CP) with a dissociation constant (Kd) value of 0.013 μmol/L, which was superior to that of myricitrin (61.447 μmol/L) and ningnanmycin (3.215 μmol/L). And the molecular docking studies were consistent with the experimental results. Therefore, these novel myricetin derivatives containing thioether quinoline moiety could become potential alternative templates for novel antiviral agents.
A C‐3 thiocyanation of 2‐aryl‐quinolin‐4‐ones in the presence of eosin‐Y and visible light has been developed. The methodology allows easy access to a variety of 2‐aryl‐3‐thiocyano‐quinolin‐4‐ones in moderate to high yields. Regioselective para‐thiocyanation of anilines has also been achieved under these conditions. The reaction is operationally simple, metal‐free, requires air as the oxidant, and proceeds smoothly at room temperature.