Ruthenium(II) Catalyzed Regiospecific C–H/O–H Annulations of Directing Arenes via Weak Coordination
摘要:
Ruthenium(II) catalyzed oxidative CH/OH annulations have been demonstrated using two different directing arenes viz. 2-arylquinolinone and 2-arylbenzoxazinone with internal alkynes. Regiospecific annulations have been observed for both directing arenes via the assistance of weaker carbonyl oxygen in the presence of a stronger nitrogen-directing site. In this substrate-controlled convergent protocol the weaker directing group dictates the annulation path.
palladium supported on graphitic carbon nitride (Pd/g-CN) catalyzed carbonylative cyclization of 2-bromonitrobenzenes and alkynes has been developed for the expedite construction of quinolin-4(1)-one scaffolds. By using a low loading heterogeneous palladium catalyst, Mo(CO) as both the CO surrogate and the reductant, and nitroarenes as the nitrogen source, the reaction proceeded well to give a variety
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.
Tunable synthesis of quinolinone-fused isoquinolines through sequential one-pot nucleophilic addition and palladium-catalyzed intramolecular C–H alkenylation
An efficient sequentialone-potsynthesis of fused heterocycles based on 4-quinolinone and isoquinoline scaffolds of biological interest has been developed. In all cases, the first nucleophilic addition of 2-aryl quinolin-4(1H)-ones to alkynyl bromides in tert-pentyl alcohol can proceed in a chemo-, regio- and stereoselective manner to give (Z)-N-(1-bromo-1-alken-2-yl)quinolin-4-ones at 110 °C. Sequentially
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。