Organocatalyst in Direct C(<sub>sp</sub><sup>2</sup>)–H Arylation of Unactivated Arenes: [1-(2-Hydroxyethyl)-piperazine]-Catalyzed <i>Inter</i>-/<i>Intra</i>-molecular C–H Bond Activation
作者:Lalit Yadav、Mohit K. Tiwari、Bharti Rajesh Kumar Shyamlal、Sandeep Chaudhary
DOI:10.1021/acs.joc.0c01019
日期:2020.6.19
promotes both inter- and intra-molecular direct C(sp2)–H arylations of unactivated arenes in the presence of potassium tert-butoxide. While the inter-molecular C–H arylation of unactivated benzenes with aryl halides (Ar–X; X = I, Br, Cl) toward biaryl syntheses underwent smoothly in the presence of only 10 mol % organocatalyst, the intra-molecular C–H arylation catalytic system composed of 40 mol % each
本文介绍的1-(2-羟乙基) -哌嗪的标识为一个新的,高性价比的,高效率的有机催化剂,其促进两者间-和内-分子直接C(SP 2)在未活化的芳烃的芳基化-H叔丁醇钾的存在。当未活化的苯与芳基卤化物(Ar–X; X = I,Br,Cl)朝联芳基合成的分子间C–H芳基化在仅有10 mol%有机催化剂存在下顺利进行,而分子内C–H芳基化催化体系,分别由40摩尔%的催化剂和添加剂(4-二甲基氨基吡啶(DMAP))组成。新型催化剂还能够同时在一个锅中同时进行分子间和分子内直接芳基化。机理研究证实了芳基自由基阴离子的参与,并通过单电子转移(SET)机制进行。较大的底物范围,较高的官能团耐受性,竞争实验,克级合成和动力学研究进一步凸显了该方法的重要性和通用性以及新催化剂的相容性。据我们所知,这是关于任何有机催化剂的第一份报告,该报告以单一形式详细报告了未活化芳烃的分子间和分子内直接C(sp 2)-H芳基化反应。
KO<sup><i>t</i></sup>Bu Mediated Synthesis of Phenanthridinones and Dibenzoazepinones
作者:Bhagat Singh Bhakuni、Amit Kumar、Shah Jaimin Balkrishna、Javeed Ahmed Sheikh、Sanjit Konar、Sangit Kumar
DOI:10.1021/ol301077y
日期:2012.6.1
Synthesis of substituted phenanthridinones and dibenzoazepinones has been realized from 2-halo-benzamides in the presence of potassium tert-butoxide and a catalytic amount of 1,10-phenanthroline or AIBN. This new carbon–carbon bond forming reaction gives direct access to various biaryl lactams containing six- and seven-membered rings chemoselectively. Carbon–carbon coupling seems to proceed by the generation
Synthesis of 3,4-Dihydroisoquinolin-1-ones from<i>N</i>-Boc-(β-Arylethyl)carbamates via Isocyanate Intermediates
作者:Jinkyung In、Soonho Hwang、Changhun Kim、Jae Hong Seo、Sanghee Kim
DOI:10.1002/ejoc.201201408
日期:2013.2
reaction conditions for the regioselectivesynthesis of isoquinolin-1-ones and related fused-ring heterocycles from N-Boc-protected (β-arylethyl)carbamates are described. The reactions involved the use of Tf2O and 2-chloropyridine and isocyanates are likely to be key intermediates. The method was extended to substrates bearing less nucleophilic aryl moieties by using Lewisacid additives, such as BF3·Et2O
Diels-Alderreactions of 3-nitro-2(1H)-quinolones with 1,3-butadiene derivatives were carried out to give the phenanthridone derivatives under both atmospheric and high pressure conditions. Furthermore, the reactivity of 3-substituted 2(1H)-quinolones acting as a dienophile with 2,3-dimethyl-1,3-butadiene was examined using molecular orbital (MO) calculation.