Visible‐Light‐Promoted Metal‐Free Synthesis of (Hetero)Aromatic Nitriles from C(sp
<sup>3</sup>
)−H Bonds**
作者:Kathiravan Murugesan、Karsten Donabauer、Burkhard König
DOI:10.1002/anie.202011815
日期:2021.2
importance in organic synthesis. We report the use of the commercially available organic dye 2,4,6‐triphenylpyrylium tetrafluoroborate (TPP) for the conversion of methylarenes to the corresponding aryl nitriles via a photocatalytic process. Applying this methodology, a variety of cyanobenzenes have been synthesized in good to excellent yield under metal‐ and cyanide‐free conditions. We demonstrate the
High Fluorine Content Bis(fluoro-Ponytailed) Bipyridine Palladium Complexes as Catalyst for Mizoroki-Heck Reactions under Fluorous Biphasic Catalysis Conditions
作者:Norman Lu、Shih-Chieh Chen、Yan-Chou Lin、Yao-Yi Cheng、Ling-Kang Liu
DOI:10.1002/jccs.200800014
日期:2008.2
1:1000. The reaction of ligands la-b with [Pd(CH 3 CN) 2 Cl 2 ] results in novel Pd complexes [PdCl2(4,4'-bis-(R f CH 2 OCH 2 )-2,2'-bpy)] where R f = n-C 10 F 21 (2a), n-C 10 F 23 (2b), respectively. The Pd complexes 2a-b are pale yellow solids, soluble only in fluorinated solvents. The Pd complexes 2a-b have been satisfactorily tested for Mizoroki-Heck arylation underfluorousbiphasiccatalysis conditions
两个高度氟化的联吡啶衍生物,(4,4'-bis(R f CH 2 OCH 2 )-2,2'-bpy) R f = nC 10 F 21 (la), nC 10 F 23 (1b)},已经从 4,4'-bis(BrCH2)-2,2'-bpy 和相应的氟化醇盐开始合成。配体la-b的氟含量分别为62.3%和63.3%,均为白色固体,几乎不溶于CH 2 Cl 2 或DMF,高度亲氟,DMF与nC 8 F 18 的分配比小于1:1000 . 配体 la-b 与 [Pd(CH 3 CN) 2 Cl 2 ] 反应生成新的 Pd 配合物 [PdCl2(4,4'-bis-(R f CH 2 OCH 2 )-2,2'-bpy) ] 其中 R f = nC 10 F 21 (2a), nC 10 F 23 (2b),分别。Pd 配合物 2a-b 是淡黄色固体,仅溶于氟化溶剂。Pd 配合物 2a-b 在氟双相催化条件下的
Recoverable Phospha-Michael Additions Catalyzed by a 4-N,N-Dimethylaminopyridinium Saccharinate Salt or a Fluorous Long-Chained Pyridine: Two Types of Reusable Base Catalysts
作者:Eskedar Tessema、Vijayanath Elakkat、Chiao-Fan Chiu、Jing-Hung Zheng、Ka Long Chan、Chia-Rui Shen、Peng Zhang、Norman Lu
DOI:10.3390/molecules26041159
日期:——
Phospha-Michael addition, which is the addition reaction of a phosphorus-based nucleophile to an acceptor-substituted unsaturated bond, certainly represents one of the most versatile and powerful tools for the formation of P-C bonds, since many different electrophiles and P nucleophiles can be combined with each other. This offers the possibility to access many diversely functionalized products. In
磷-迈克尔加成反应是磷基亲核试剂与受体取代的不饱和键的加成反应,它无疑是形成PC键的最通用,最强大的工具之一,因为可以使用许多不同的亲电试剂和P亲核试剂。彼此结合。这提供了访问许多功能多样的产品的可能性。在这项工作中,使用了两种基于吡啶的碱性有机催化剂有效地催化磷-迈克尔加成反应:4- N,N-二甲基氨基吡啶糖精盐(DMAP·Hsac)盐和氟长链吡啶(4- R f -CH 2 OCH 2 -py,其中R f = C11楼23)。这些催化剂已经合成并且由Lu's基团表征。在这些催化剂存在下,亚磷酸二异丙酯,亚甲基二甲基或三乙基亚磷酸酯在α,β-不饱和丙二酸酯中的磷-迈克尔加成反应显示出非常好的反应性,在80-100°C下可在1-4.5 h内获得高收率,并具有高催化回收率和可重复使用性。关于显着的催化剂回收,有时通过使用非极性溶剂(例如醚)使催化剂析出,DMAP·Hsac加合物有时观察到超过八
Local lamellar organisation of discotic mesogens carrying fluorinated tails
作者:Paul H. J. Kouwer、Stephen J. Picken、Georg H. Mehl
DOI:10.1039/b707880c
日期:——
A series of disc-shaped liquid crystals, monomers and dimers, have been investigated. A spacer linked to the pentakis(phenylethynyl)phenoxy core of the mesogens was substituted with perfluorinated chains to investigate the microphase segregating effect of such groups. The nematic phase, commonly found for these mesogens, is strongly stabilised by the presence of the fluorinated groups. X-Ray diffraction studies indicate clearly the onset of nanophase segregation in the nematic phase. Remarkable is the result, that the nanophase segregation directs the systems towards a lamellar organisation, rather than the columnar order that is commonly found for disc-shaped mesogens. This is also confirmed by the order in the underlying crystalline phase. X-Ray diffraction studies of the nematic phase show the characteristics of cybotactic smectic clustering, which has not been observed for discotic systems so far.
对一系列圆盘状液晶、单体和二聚体进行了研究。用全氟链取代了与中间体的五(苯乙炔基)苯氧基核心相连的间隔物,以研究这些基团的微相分离效应。氟化基团的存在极大地稳定了这些介聚物常见的向列相。X 射线衍射研究清楚地表明,向列相中开始出现纳米相分离。值得注意的是,纳米相分离将系统引向了片状组织,而不是圆盘状介质中常见的柱状秩序。底层结晶相的有序性也证实了这一点。对向列相进行的 X 射线衍射研究显示了线状聚类的特征,这是迄今为止在盘状介质系统中尚未观察到的。