19402-83-6Relevant academic research and scientific papers
Structural Effect of Pincer Pd(II)–ONO Complexes Modified with Acylthiourea on Sizes of the In Situ Generated Pd Nanoparticles During Heck Coupling Reaction
Jerome,Babu, S. Ganesh,Karvembu
, p. 1633 - 1645 (2020/10/15)
Abstract: The Pd nanoparticles generated in situ from Pd–pincer complexes catalyzed Heck coupling reaction. For this purpose, new Pd(II)–ONO pincer complexes (1–4) containing acylthiourea ancillary ligand were obtained by treating [Pd(ONO)(CH3CN)] with the respective N-substituted carbamothioyl benzamide ligand (L1–L4). Formation of these complexes was confirmed by UV–Visible, FT-IR, NMR and mass spectroscopic techniques. The sizes of in situ formed Pd nanoparticles were greatly affected by the substituent in ancillary ligand, which in turn influenced their catalytic activity towards Heck coupling reaction. The in situ formed Pd nanoparticles during Heck reaction were removed from the reaction medium and analyzed using HR-TEM to estimate the sizes of the Pd nanoparticles. Complex [Pd(ONO)((N-benzylcarbamothioyl)benzamide)] (1) which does not possess any substituent on the benzyl moiety of acylthiourea produced the smallest Pd nanoparticles with the average particle size of 3.7?nm. Hence, complex 1 showed the utmost catalytic activity. With complex 1, 51–99% of conversion was observed during Heck coupling reaction of styrene with various aryl halides. XPS results confirmed that the recovered black particles were Pd(0). A reasonable recyclability results were achieved by these in situ generated Pd nanoparticles. Graphic Abstract: [Figure not available: see fulltext.]
Pd-Catalyzed Oxidative Heck Reaction of Grignard Reagents with Diaziridinone as Oxidant
Dai, Qipu,Zhao, Baoguo,Yang, Yihui,Shi, Yian
supporting information, p. 5157 - 5161 (2019/07/04)
A novel Pd-catalyzed oxidative Heck reaction with readily available Grignard reagents using di-t-butyldiaziridinone as an oxidant has been developed. Various substituted olefins were obtained in 46-91% yields with high regioselectivity under mild reaction conditions.
Synthesis of Highly Substituted Arenes via Cyclohexadiene-Alkene C-H Cross Coupling and Aromatization
Bhunia, Anup,Studer, Armido
, p. 1213 - 1217 (2018/02/14)
The development of a cross-coupling method for the regioselective β-alkenylation of 2,5-cyclohexadiene carboxylic acid derivatives to form ortho-alkenylarenes through in situ decarboxylation and aromatization is described. The carboxylic acid functionality is used as a traceless directing group for efficient and mild β-alkenylation. The modular sequence comprises a reductive Birch α-alkylation, ionic ?-alkylation followed by a Pd-catalyzed decarboxylative β-alkenylation with subsequent aromatization resulting in an overall three-fold ipso-para-ortho functionalization of readily accessed benzoic acid derivatives. Efficient synthesis of various alkyl-alkenylarenes under mild conditions in moderate to excellent yields is presented.
Open-air oxidative Mizoroki-Heck reaction of arylsulfonyl hydrazides with alkenes
Yuen, On Ying,So, Chau Ming,Kwong, Fuk Yee
, p. 27584 - 27589 (2016/03/30)
A palladium(ii)-catalyzed oxidative Mizoroki-Heck reaction of arylsulfonyl hydrazides with alkenes was developed employing atmospheric air as the sole oxidant in an open-vessel manner. By using palladium(ii) acetate associating with inexpensive, air-stable and moisture stable pyridine ligand L9 as the catalyst system, the efficiency of the reaction could be significantly enhanced. A wide range of arylsulfonyl hydrazides underwent the oxidative Mizoroki-Heck reaction with alkenes smoothly. Good-to-excellent product yields and excellent regio- and stereoselectivity were achieved. Functional groups such as halo, ester etc. were well-tolerated under these optimized reaction conditions.
Geometry constrained N-(5,6,7-trihydroquinolin-8-ylidene)arylaminopalladium dichloride complexes: Catalytic behavior toward methyl acrylate (MA), methyl acrylate-co-norbornene (MA-co-NB) polymerization and heck coupling
Zeng, Yanning,Mahmood, Qaiser,Liang, Tongling,Sun, Wen-Hua
, (2016/12/30)
A new pair of plladium complexes (Pd4 and Pd5) ligated with constrained N-(5,6,7-trihydroquinolin-8-ylidene)arylamine ligands have been prepared and well characterized by 1H-, 13C-NMR and FTIR spectroscopies as well as elemental analysis. The molecular structure of Pd4 and Pd5 in solid state have also been determined by X-ray diffraction, showing slightly distorted square planar geometry around the palladium metal center. All complexes Pd1-Pd5 are revealed highly efficient catalyst in methyl acrylate (MA) polymerization as well as methyl acrylate/norbornene (MA/NB) copolymerization. In the case of MA polymerization, as high as 98.4% conversion with high molecular weight up to 6282 kg·mol-1 was achieved. Likewise, Pd3 complex has good capability to incorporate about 18% NB content into MA polymer chains. Furthermore, low catalyst loadings (0.002 mol %) of Pd4 or Pd5 are able to efficiently mediate the coupling of haloarenes with styrene affording up to 98% conversion.
Palladium catalyst supported on PEGylated imidazolium based phosphinite ionic liquid-modified magnetic silica core-shell nanoparticles: A worthy and highly water-dispersible catalyst for organic reactions in water
Bahadorikhalili, Saeed,Ma'mani, Leila,Mahdavi, Hossein,Shafiee, Abbas
, p. 71297 - 71305 (2015/09/08)
A highly water-dispersible palladium nanocatalyst was fabricated by the immobilization of Pd onto the surface of PEGylated imidazolium based phosphinite ionic liquid functionalized γ-Fe2O3@SiO2 core-shell nanoparticles. This nanocatalyst (denoted as [Pd@PEGylated ImIL-OPPh2-γ-Fe2O3@SiO2]) was assessed as a promising Pd catalyst in different organic reactions including Mizoroki-Heck and Sonogashira coupling reactions of aryl halides and the reduction reaction of 4-nitrophenol (4NP) to 4-aminophenol (4AP). From the application point of view, this nanocatalyst showed high thermal versatility, stability, recoverability, and compatibility in aqueous media. The catalyst recovery test revealed that its performance and catalytic activity stayed indefectible during several sequential runs. The loading level of Pd in the [Pd@PEGylated ImIL-OPPh2-γ-Fe2O3@SiO2] catalyst was 0.087 mmol g-1. Pivotal properties including high robustness, efficiency and turnover frequency (TOF), mild reaction conditions, utilization of water as a green solvent, simple product work-up, and facile catalyst recovery make this catalyst favourable from the environmental and economic points of view.
Enhancing catalytic activity towards Heck-reaction by using 4,5,9,10-tetra(arylimino)pyrenylidenyldipalladium tetrachlorides
Zhao, Tong,Xing, Qifeng,Song, Kuifeng,Ban, Qing,Liang, Tongling,Liu, Qingbin,Sun, Wen-Hua
, p. 14228 - 14234 (2015/02/19)
A series of binuclear 4,5,9,10-tetra(arylimino)pyrenylidenyldipalladium(ii) tetrachloride complexes (Pd1-Pd4) was synthesized and characterized by FT-IR and NMR spectroscopy as well as elemental analysis. The molecular structures of representative complexes Pd1 and Pd2 were determined by single crystal X-ray diffraction to reveal a square planar geometry around the palladium centre. The complex Pd1 dissolved in the presence of ethanol to form mono-palladium complex C1, whose structure was also confirmed by single crystal X-ray diffraction. All binuclear palladium complexes promote the Heck cross-coupling reactions with high activities; the reaction can be carried out for various substrates and activators (basic compounds) and also in various solvents. The binuclear palladium complexes exhibit significantly higher efficiency than do their mono-palladium complexes bearing 4,5-bis(arylimino)pyrenylidenes.
Organoaluminum-Mediated Direct Cross-Coupling Reactions
Minami, Hiroki,Saito, Tatsuo,Wang, Chao,Uchiyama, Masanobu
, p. 4665 - 4668 (2015/04/14)
We present a direct cross-coupling reaction between arylaluminum compounds (ArAlMe2·LiCl) and organic halides RX (R=aryl, alkenyl, alkynyl; X=I, Br, and Cl) without any external catalyst. The reaction takes place smoothly, simply upon heating, thereby enabling the efficient and chemo-/stereoselective formation of biaryl, alkene, and alkyne coupling products with broad functional group compatibility.
Synthesis and catalytic activity of pyrazolyl-functionalized N-heterocyclic carbene palladium complexes
Cheng, Cai-Hong,Xu, Jia-Ru,Song, Hai-Bin,Tang, Liang-Fu
, p. 151 - 157 (2014/03/21)
Three pyrazolyl-functionalized N-heterocyclic carbene (NHC) palladium complexes based on 1-[2-(pyrazol-1-yl)phenyl]imidazole have been synthesized and characterized by physico-chemical and spectroscopic methods, and the structures of two of the complexes have been confirmed by single-crystal X-ray diffraction. The pyrazolyl-functionalized NHCs act as chelating N,C-bidentate ligands in these three complexes. Catalytic tests have proved that these complexes exhibit highly effective catalytic activity for the Suzuki-Miyaura and Mizoroki-Heck coupling reactions in water or aqueous/organic media under air. The substituents on the pyrazolyl ring exert different influences on the catalytic activity of the complexes in these coupling reactions.
Aromatic C-H coupling with hindered arylboronic acids by Pd/Fe dual catalysts
Yamaguchi, Kazuya,Kondo, Hiroki,Yamaguchi, Junichiro,Itami, Kenichiro
, p. 3753 - 3757 (2013/11/19)
An aerobic oxidative coupling of arenes/alkenes with arylboronic acids (C-H/C-B coupling) using catalytic Pd(ii)-sulfoxide-oxazoline (sox) ligand and iron-phthalocyanine (FePc) has been developed. This dual catalyst system enables the synthesis of sterica
