An efficient oxidation of 2-aryl-1,2,3,4-tetrahydro-4-quinolones employing ferric chloride hexahydrate–methanol: synthesis of naturally occurring 4-alkoxy-2-arylquinolines
摘要:
A simple, inexpensive and efficient oxidation of 2-aryl-1,2,3,4-tetrahydro-4-quinolones has been carried out by employing FeCl3-6H(2)O-methanol under mild conditions. This method has been investigated for the synthesis of an endothelin receptor antagonist, benzofuro[3,2-b]pyridine core structure. (C) 2004 Elsevier Ltd. All rights reserved.
Bifunctional catalysts bearing two catalytic sites, Lewis acidic organometallic titanocene and Brønsted acidic COOH, have been assembled in situ from Cp2TiCl2 with carboxylic acid ligands, showing high catalytic activity over an intramolecular Mannich reaction towards synthesis of 2‐aryl‐2,3‐dihydroquinolin‐4(1H)‐ones. The determination of the bifunctional catalyst Cp2Ti(C8H4NO6)2 was elucidated by
具有羧酸催化配体的Cp 2 TiCl 2原位组装了带有两个催化位点的Lewis酸性有机金属钛茂和Brønsted酸性COOH双功能催化剂,在分子内曼尼希反应中对2-芳基-2,3的合成显示出高催化活性。 -dihydroquinolin-4(1H)-1。双功能催化剂Cp 2 Ti(C 8 H 4 NO 6)2的测定单个X射线HRMS和催化行为的研究阐明了这一点。特别是,用休眠的COOMe掩盖布朗斯台德酸性COOH催化位点会大大降低反应产率,这表明两个催化位点共同作用以保持高催化效率。
β-Cyclodextrin in water: highly facile biomimetic one pot deprotection of phenolic THP/MOM/Ac/Ts ethers and concomitant regioselective cyclization of chalcone epoxides and 2′-aminochalcones
作者:Sumit Kumar、Nishant Verma、Naseem Ahmed
DOI:10.1039/c5ra15996b
日期:——
A mild and efficient one-pot deprotection of THP/MOM/Ac/Tsethers and the concomitant cyclization of chalconeepoxides to 2-hydroxyindanones or 2′-aminochalcones to aza-flavanones using β-cyclodextrin in water has been developed. β-CD was found to be highly effective at carrying out the deprotection and sequential transformations in an eco-friendly environment affording moderate to excellent yields
已经开发了在水中使用β-环糊精对THP / MOM / Ac / Ts醚进行温和有效的一锅脱保护以及将查尔酮环氧化物伴随环化为2-羟基茚满酮或2'-氨基查耳酮为氮杂黄酮的过程。发现β-CD在生态友好的环境中进行脱保护和顺序转化非常有效,在60°C下8-22分钟内可提供中等至极好的收率(59-99%)。在该反应中首次使用了水,这是一种生态友好的反应介质。所提出的方案的优点包括高产率和催化剂的可重复使用性,并且该方案排除了金属和有机溶剂的使用。与先前报道的方法相比,本方法温和得多,但更先进。
A Green, Solvent-Free, Microwave-Assisted, High-Yielding YbCl<sub>3</sub>Catalyzed Deprotection of THP/MOM/Ac/Ts Ethers of Chalcone Epoxide and 2′-Aminochalcone and Their Sequel Cyclization
作者:Sumit Kumar、Nishant Verma、Iram Parveen、Naseem Ahmed
DOI:10.1002/jhet.2517
日期:2016.11
Under microwave and solvent‐free conditions, YbCl3 efficiently catalyzed the deprotection of tetrahydropyran‐2‐yl, methoxymethyl (MOM), acetyl, and tosyl groups and sequelcyclization of chalconeepoxide to 2‐hydroxyindanone and 2′‐aminochalcone to aza‐flavanone. The reaction afforded the products in excellent yield (78–99%) at 850 W microwave heating within 1–5 min under eco‐friendly conditions. The
Simple and Efficient Synthesis of 2-Aryl-2,3-Dihydroquinolin-4(1<i>H</i>)-ones Using Silica Chloride as a New Catalyst Under Solvent-Free Conditions
作者:M. Muthukrishnan、M. Mujahid、V. Punitharasu、D. A. Dnyaneshwar
DOI:10.1080/00397910903097252
日期:2010.4.12
A mild, efficient, and high-yielding method for the synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-ones from their corresponding 2-amino chalcones using silica chloride (SiO2Cl) under solvent-free conditions is described. A series of 2-aryl-2,3-dihydroquinolin-4(1H)-ones containing both electron-donating and electron-withdrawing substituents were synthesized.