在本文中,作者报告了 1-吡啶基-2-芳基乙烯、1-呋喃基-2-芳基乙烯、1,2-二苯基丙烯和取代的肉桂基苯胺作为类二苯乙烯的模型化合物,以研究主导取代基推挽效应的因素通过使用桥键碳原子的核磁共振化学位移。证明了最大推挽效应并不总是在 D-π-A 化合物中的强给电子 D 和强电子接受 A 基团之间。D-π-A化合物中取代基推挽作用的作用方式主要由其分子母体结构决定。组的场/感应效应和共轭效应对推挽效应的贡献是不相等的。当 D-π-A 母体分子在一个平面上时,组的场/感应效应对推挽效应的影响大于或接近其共轭效应的影响。虽然母体分子是空间扭曲的,但推挽效应主要取决于基团的共轭效应。本文的结果可以为我们提供关于取代基推拉效应的新见解。
The bis-1,4-dimesityl-1,2,3-triazol-5-ylidene–palladium complex (1a) successfully catalyzes the Mizoroki–Heck and Sonogashira coupling reactions with aryl bromides to give the corresponding alkenes and alkynes, respectively, in good to excellent yields. In the Mizoroki–Heck reaction, electron-rich, electron-poor, and functionalized aryl bromides and alkenes are tolerated, while the substrates are limited
Preparation of Vinyl Arenes by Nickel-Catalyzed Reductive Coupling of Aryl Halides with Vinyl Bromides
作者:Jiandong Liu、Qinghua Ren、Xinghua Zhang、Hegui Gong
DOI:10.1002/anie.201607959
日期:2016.12.12
This work emphasizes the synthesis of substituted vinyl arenes by reductive coupling of arylhalides with vinyl bromides under mild and easy‐to‐operate nickel‐catalyzed reaction conditions. A broad range of arylhalides, including heteroaromatics, and vinyl bromides were employed to yielding products in moderate to excellent yields with high functional‐group tolerance. The nickel‐catalytic system displays
作者:Qiang-Qiang Li、Zaher Shah、Jian-Ping Qu、Yan-Biao Kang
DOI:10.1021/acs.joc.7b02720
日期:2018.1.5
A base-promoted transition metal-free approach to substituted alkenes using alcohols under aerobic conditions using air as the inexpensive and clean oxidant is described. Aldehydes are relatively difficult to handle compared to corresponding alcohols due to their volatility and penchant to polymerize and autoxidize. Wittig ylides are easily oxidized to aldehydes and consequently form homo-olefination
Lewis-Acid-Catalyzed Benzylic Reactions of 2-Methylazaarenes with Aldehydes
作者:Dan Mao、Gang Hong、Shengying Wu、Xin Liu、Jianjun Yu、Limin Wang
DOI:10.1002/ejoc.201400073
日期:2014.5
Lewis-acid-catalyzedbenzylicreactions of 2-methylazaarenes with aldehydes have been investigated. Series of azaarene derivatives were afforded by this reaction. 2-(Pyridin-2-yl)ethanols with common substituents were formed through the LiNTf2-promoted aldol reaction for the first time. 2-Alkenylpyridines, exclusively in the form of the E isomers, were synthesized in the presence of LiNTf2 cooperated
已经研究了路易斯酸催化的 2-甲基氮杂芳烃与醛的苄基反应。该反应得到一系列氮杂芳烃衍生物。首次通过LiNTf2促进的羟醛反应形成了具有常见取代基的2-(Pyridin-2-yl)乙醇。在 LiNTf2 与 H2NTf 协同作用下,合成了仅以 E 异构体形式存在的 2-烯基吡啶。在La(Pfb)3催化下,2-甲基喹啉与醛类在空气中反应,以高收率得到2-烯基喹啉。
Anil-Synthese 22. Mitteilung über die Herstellung von Styryl-und Distyryl-Derivaten des Pyridins
作者:Adolf Emil Siegrist、Hans Rudolf Meyer、Peter Gassmann、Serge Moss
DOI:10.1002/hlca.19800630524
日期:1980.7.9
Preparation of Styryl and Distyryl Derivatives of Pyridine