Palladium (II)–Salan Complexes as Catalysts for Suzuki–Miyaura C–C Cross-Coupling in Water and Air. Effect of the Various Bridging Units within the Diamine Moieties on the Catalytic Performance
salan ligands were synthesized by hydrogenation and subsequent sulfonation of salens (N,N’-bis(slicylidene)ethylenediamine and analogues) with various bridging units (linkers) connecting the nitrogen atoms. Pd (II) complexes were obtained in reactions of sulfosalans and [PdCl4]2−. Characterization of the ligands and complexes included extensive X-ray diffraction studies, too. The Pd (II) complexes proved
水溶性的 salan 配体是通过对具有连接氮原子的各种桥接单元(接头)的 salens(N,N'-双(亚硅基)乙二胺和类似物)进行氢化和随后的磺化来合成的。Pd (II) 配合物是在硫柳胺和 [PdCl4]2- 的反应中获得的。配体和配合物的表征也包括广泛的 X 射线衍射研究。Pd (II) 配合物被证明是芳基卤化物和芳基硼酸衍生物在 80°C 下在水和空气中的 Suzuki-Miyaura 反应的高活性催化剂。对 Pd (II)-磺胺嘧啶催化剂的比较研究表明,催化活性随着接头长度的增加和配体 N 供体原子周围空间拥挤度的增加而大大增加;最高比活为40,000(mol底物)(mol催化剂×h)-1。
Visible-Light-Promoted, Catalyst-Free Gomberg–Bachmann Reaction: Synthesis of Biaryls
作者:Juyoung Lee、Boseok Hong、Anna Lee
DOI:10.1021/acs.joc.9b00557
日期:2019.7.19
Biaryls were synthesized via a novel visible-light-promoted Gomberg–Bachmann reaction that does not require a photosensitizer or any metal reagents. The formation of an electron donor–acceptor complex between aryl diazonium salts and pyridine allows, under visible-light irradiation, the synthesis of biaryls in moderate-to-high yields.
Selective Suzuki-Miyaura Monocouplings with Symmetrical Dibromoarenes and Aryl Ditriflates for the One-Pot Synthesis of Unsymmetrical Triaryls
作者:Corinne Minard、Carole Palacio、Kevin Cariou、Robert H. Dodd
DOI:10.1002/ejoc.201400090
日期:2014.5
parameters that would permit selectiveSuzuki–Miyauramonocouplings of symmetrical dihaloarenes were studied. High selectivity and efficiency can be obtained for a broad range of substrates by using operationally simple conditions and widely available reagents. The 38 different examples described provide a valuable toolbox for the rapid access to unsymmetricaltriaryls, as illustrated by the preparation
Monoarylation of Dibromoarenes by Simple Palladium Catalyst Systems: Efficient Synthesis of Bromobiaryls from Dibromoarenes and Arylboronic Acids
作者:Qiao-Sheng Hu、Cheng-Guo Dong、Tao-Ping Liu
DOI:10.1055/s-0028-1088110
日期:2009.4
arylboronic acids to formbromobiaryls in good to excellent yields are described. Our studyshowed that readily available Pd/C/Ph 3 Pand Pd(PPh 3 ) 4 /Ph 3 P werepractically useful catalysts for the synthesis of bromobiaryls fromdibromo-arenes.
POLYMERIZABLE COMPOUNDS AND THE USE THEREOF IN LIQUID-CRYSTAL DISPLAYS
申请人:MERCK PATENT GMBH
公开号:US20160362606A1
公开(公告)日:2016-12-15
The present invention relates to polymerizable compounds, to processes and intermediates for the preparation thereof, to liquid-crystal media comprising them, and to the use of the polymerizable compounds and liquid crystalline media for optical, electro-optical and electronic purposes, in particular in liquid crystalline displays, especially in liquid crystalline displays of the polymer sustained alignment type.