Photocyclization of benzalcycloalkanone oximes. A photoannulation route to quinolines.
摘要:
Photolysis of benzalcycloalkanone oxime derivatives in acidic methanol produces quinoline derivatives in good yields. A three step quinoline annulation of cyclic ketones is described.
Efficient catalytic one‐step synthesis of substituted quinoline derivatives using newly synthesized Ru(II) half‐sandwich complexes of the type [Ru(η6‐p‐cymene)Cl(L)] (L = pyrrole‐2‐aldehydehydrazones) under mild conditions is described. The synthesized complexes exhibit excellent catalytic activity towards the coupling of 2‐amino alcohol with functionalized ketones and secondary alcohols in the optimal
作者:Rahul P.、Nitha P. R.、Vishnu K. Omanakuttan、Sheba Ann Babu、P. Sasikumar、Vakayil K. Praveen、Henning Hopf、Jubi John
DOI:10.1002/ejoc.202000365
日期:2020.5.29
A transition metal‐free superbase mediated indirectFriedländer reaction was developed for accessing functionalized quinolines using o‐aminobenzyl alcohol and ketones with an active methylene moiety. The reaction was employed in the functionalization of natural products and the applicability of the reaction for gram‐scale synthesis of quinolines was also demonstrated.
Homogeneous Nickel-Catalyzed Sustainable Synthesis of Quinoline and Quinoxaline under Aerobic Conditions
作者:Amreen K. Bains、Vikramjeet Singh、Debashis Adhikari
DOI:10.1021/acs.joc.0c01819
日期:2020.12.4
efficient route toward the synthesis of a plethora of heterocyclic rings. Herein, we report an efficacious, nickel-catalyzed synthesis of two important heterocycles such as quinoline and quinoxaline. The catalyst is molecularly defined, is phosphine-free, and can operate at a mild reaction temperature of 80 °C. Both the heterocycles can be easily assembled via double dehydrogenative coupling, starting
基于脱氢偶合的反应已成为合成大量杂环的有效途径。本文中,我们报道了两个重要杂环(如喹啉和喹喔啉)的高效,镍催化合成。该催化剂是分子定义的,不含膦,可以在80°C的温和反应温度下运行。两个杂环可以容易地组装经由在较短的反应时间内,分别从2-氨基苄醇/ 1-苯乙醇和二胺/二醇开始的双脱氢偶联。这种使用廉价催化剂的环境友好的合成方案可以与许多其他为制造两个推定的杂环而开发的过渡金属系统相媲美。从机理上讲,仲醇的脱氢遵循干净的拟一级动力学,并表现出相当大的动力学同位素效应。有趣的是,这种催化剂提供了一个将捕获的氢存储在配体主链中,避免形成金属氢化物的例子。在好氧/ O 2氧化作用下,催化剂的氧化形式易于再生,从而使该方案变得环保且易于处理。
Bioinspired Radical‐Mediated Transition‐Metal‐Free Synthesis of N‐Heterocycles under Visible Light
作者:Amreen K. Bains、Yadav Ankit、Debashis Adhikari
DOI:10.1002/cssc.202002161
日期:2021.1.7
extended to multi‐component, one‐pot coupling for the synthesis of quinoline and pyrimidine. This organocatalytic approach is very mild (70 °C, 8 h) compared to a multitude of transition‐metal catalysts that have been used to prepare these heterocycles. A detailed mechanistic study proves the intermediacy of the iminosemiquinonate‐type radical and a critical hydrogen atom transfer step to be involved
Improved ruthenium catalysts for the modified Friedlaender quinoline synthesis
作者:Hans Vander Mierde、Nele Ledoux、Bart Allaert、Pascal Van Der Voort、Renata Drozdzak、Dirk De Vos、Francis Verpoort
DOI:10.1039/b707292a
日期:——
Herein we describe an improved ruthenium catalyst for the oxidative cyclization of 2-aminobenzylalcohol with ketones, leading to quinolines via a modified Friedlaender synthesis.