- Sterically enhanced 2-iminopyridylpalladium chlorides as recyclable ppm-palladium catalyst for Suzuki–Miyaura coupling in aqueous solution
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Sterically hindered 2-iminopyridine derivatives and their palladium chlorides complexes are designed and prepared, which efficiently promote the Suzuki–Miyaura coupling (SMC) reaction in aqueous solution. Besides the good to excellent yields and broad substrate scope, these catalysts can be reused for at least four new batches of the substrates. Spontaneous separation of coupling products in the aqueous reaction medium is the additional striking feature of this catalytic process. Furthermore, catalytic performance of palladium complexes bearing the azo-bridged phenyl groups was greatly influenced by the UV irradiation due to the cis/trans photoisomerization of azo unit of the catalysts. In conclusion, titled palladium complexes provide a green, sustainable, cost-effective, and convenient process to synthesize SMC products at multi-gram-scale reaction.
- Lin, Wenhua,Zhang, Liping,Ma, Yanping,Liang, Tongling,Sun, Wen-Hua
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- Synthesis of ultrafine AuPd bimetallic nanoparticles using a magnetite-cored poly(propyleneimine) dendrimer template and its sustainable catalysis of the Suzuki coupling reaction
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The poly(propyleneimine) PPI dendrimer with active amino groups and specific voids is an excellent template for the encapsulation and stabilization of size and shape-controlled metal nanoparticles. The magnetite-cored PPI dendrimer up to third generation was synthesized by a divergent method in our previous report. Bimetallic nanoparticles are more advantageous than monometallic nanoparticles in catalysis due to their synergistic effect between two metals, especially Au and Pd nanoparticles. Herein, we present the synthesis of highly monodispersed ultrafine AuPd bimetallic nanoparticles of size 3-6 nm using the magnetic-cored PPI dendrimer through a facile and convenient method without external stabilizers. The formation of the monodispersed bimetallic nanoparticles on the dendritic entity was confirmed through HRTEM, HRSEM, EDAX, XRD, XPS and VSM. The excellent structural behavior of the magnetic-cored PPI dendrimers proves their ability to encapsulate AuPd bimetallic nanoparticles, and also attain better dispersibility, stability, and improved efficacy compared to conventional dendrimer-encapsulated metal nanoparticles. Most predominantly, it was isolated by simple magnetic attraction. TheAuPd@PPI@Fe3O4/SiO2nanomaterial was utilized as a potential green catalyst in the Suzuki coupling reaction under ambient reaction conditions with greater reactivity and stability. Coupling products were characterized by1H and13C NMR. This material retained its catalytic activity in the coupling reaction for up to eight consecutive catalytic cycles.
- Lakshmi, Kannappan,Rangasamy, Rajmohan,Selvaraj, Mari
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p. 14227 - 14235
(2021/08/16)
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- Double-anthracene D-delta-A type dark blue organic fluorescent material, and preparation method and application thereof
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The invention relates to a double-anthracene D-delta-A type dark blue organic fluorescent material, and a preparation method and an application thereof. The structural formula of the material is shownin the specification; and in the formula, R1 is an elec
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Page/Page column 0050; 0075; 0076
(2020/07/15)
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- When Anthracene and Quinone Avoid Cycloaddition: Acid-Catalyzed Redox Neutral Functionalization of Anthracene to Aryl Ethers
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Benzoquinone and 9-phenylanthracene barely undergo anticipated cycloaddition under acid catalysis. Instead, 9-anthracenyl aryl ethers are obtained as unexpected products. Mechanistic studies indicate that the reaction likely undergoes an ionic mechanism between protonated anthracene species and nucleophilic oxygen of 1,4-benzoquinone or 1,4-hydroquinone. A variety of 9-anthracenyl aryl ethers are constructed with this method. Produced anthracenyl aryl ethers are potential scaffolds for new fluorescent molecules.
- Ding, Nan,Ding, Nan,Ding, Nan,Li, Zhi
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supporting information
p. 4276 - 4282
(2020/06/04)
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- D-A type organic blue fluorescent material as well as preparation method and application thereof
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The invention relates to a D-A type organic blue fluorescent material as well as a preparation method and application thereof. The molecular design strategy of the material is to take benzene as a central pi-conjugated bridge chain, and connect two anthra
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Paragraph 0067-0068; 0071-0072; 0075-0076
(2019/04/04)
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- D-A type organic blue fluorescent material based on dianthracene as well as preparation method and application of organic blue fluorescent material
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The invention relates to a D-A type organic blue fluorescent material based on dianthracene as well as a preparation method and application of the organic blue fluorescent material. The molecular design of the material takes benzene as a central conjugate
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Paragraph 0068; 0069; 0073; 0074; 0077; 0078
(2019/05/08)
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- Chromium- and Cobalt-Catalyzed, Regiocontrolled Hydrogenation of Polycyclic Aromatic Hydrocarbons: A Combined Experimental and Theoretical Study
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Polycyclic aromatic hydrocarbons are difficult substrates for hydrogenation because of the thermodynamic stability caused by aromaticity. We report here the first chromium- and cobalt-catalyzed, regiocontrolled hydrogenation of polycyclic aromatic hydrocarbons at ambient temperature. These reactions were promoted by low-cost chromium or cobalt salts combined with diimino/carbene ligand and methylmagnesium bromide and are characterized by high regioselectivity and expanded substrate scope that includes tetracene, tetraphene, pentacene, and perylene, which have rarely been reduced. The approach provides a cost-effective catalytic protocol for hydrogenation, is scalable, and can be utilized in the synthesis of tetrabromo- and carboxyl-substituted motifs through functionalization of the hydrogenation product. The systematic theoretical mechanistic modelings suggest that low-valent Cr and Co monohydride species, most likely from zerovalent transition metals, are capable of mediating these hydrogenations of fused PAHs.
- Han, Bo,Ma, Pengchen,Cong, Xuefeng,Chen, Hui,Zeng, Xiaoming
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supporting information
p. 9018 - 9026
(2019/06/13)
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- Solid-state Suzuki-Miyaura cross-coupling reactions: Olefin-accelerated C-C coupling using mechanochemistry
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The Suzuki-Miyaura cross-coupling reaction is one of the most reliable methods for the construction of carbon-carbon bonds in solution. However, examples for the corresponding solid-state cross-coupling reactions remain scarce. Herein, we report the first broadly applicable mechanochemical protocol for a solid-state palladium-catalyzed organoboron cross-coupling reaction using an olefin additive. Compared to previous studies, the newly developed protocol shows a substantially broadened substrate scope. Our mechanistic data suggest that olefin additives might act as dispersants for the palladium-based catalyst to suppress higher aggregation of the nanoparticles, and also as stabilizer for the active monomeric Pd(0) species, thus facilitating these challenging solid-state C-C bond forming cross-coupling reactions.
- Seo, Tamae,Ishiyama, Tatsuo,Kubota, Koji,Ito, Hajime
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p. 8202 - 8210
(2019/09/19)
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- Substituted aromatic compound, a blue light-emitting materials, the organic EL element
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PROBLEM TO BE SOLVED: To provide a substituted aromatic compound, a blue light-emitting material using the same and having high color reproducibility, high color purity and high efficiency, and an organic electroluminescent (EL) element.SOLUTION: The substituted aromatic compound is represented by the general formula [1], where Rto Rare each independently hydrogen or a C1-C4 linear or branched alkyl group; A is hydrogen, a C1-C4 linear or branched alkyl group, or a C1-C4 linear or branched alkoxy group; and EWG is a cyano group or a trifluoromethyl group.
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Paragraph 0070; 0071
(2018/10/10)
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- A combinational molecular design to achieve highly efficient deep-blue electrofluorescence
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A deep-blue emitter 1-(10-(4-methoxyphenyl)anthracen-9-yl)-4-(10-(4-cyanophenyl)anthracen-9-yl)tetraphenylethene (TPEA) has been successfully prepared by a combinational molecular design, which contains triplet-triplet fusion (TTF) and hybridized local ch
- Bian, Mengying,Zhao, Zifeng,Li, Yu,Li, Qing,Chen, Zhijian,Zhang, Dongdong,Wang, Shufeng,Bian, Zuqiang,Liu, Zhiwei,Duan, Lian,Xiao, Lixin
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p. 745 - 753
(2018/02/07)
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- ORGANIC LIGHT EMITTING DEVICE
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An organic light-emitting device having high efficiency and long lifespan including: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode and including an emission layer, wherein the organic layer includes a first compound represented by Formula 1 and a second compound represented by Formula 2: When compounds represented by Formulae 1 and 2 are included in the emission layer, organic light-emitting devices may exhibit improved driving voltage, improved luminance, improved efficiency, and/or improved lifespans.
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- A blue fluorescent light-emitting material and its application
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The invention relates to a blue-fluorescence material and an application thereof. The blue-fluorescence material and the application thereof start from the perspective of molecular design, tetraphenyl ethylene is taken as the core, and an electron-donatin
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Paragraph 0014; 0052
(2017/12/01)
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- SELF-ORGANIZABLE POLYCYCLIC AROMATIC COMPOUND AND ORGANIC EL ELEMENT PREPARED THEREWITH
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PROBLEM TO BE SOLVED: To provide an organic EL element having excellent durability. SOLUTION: The present invention provides a polycyclic aromatic compound represented by general formula (1), and an organic electroluminescent element comprising the compou
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Paragraph 0204
(2017/05/10)
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- A General Palladium-Catalyzed Hiyama Cross-Coupling Reaction of Aryl and Heteroaryl Chlorides
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A general palladium-catalyzed Hiyama cross-coupling reaction of aryl and heteroaryl chlorides with aryl and heteroaryl trialkoxysilanes by a Pd(OAc)2/L2 catalytic system is presented. A newly developed water addition protocol can dramatically improve the product yields. The conjugation of the Pd/L2 system and the water addition protocol can efficiently catalyze a broad range of electron-rich, -neutral, -deficient, and sterically hindered aryl chlorides and heteroaryl chlorides with excellent yields within three hours and the catalyst loading can be down to 0.05 mol % Pd for the first time. Hiyama coupling of heteroaryl chlorides with heteroaryl silanes is also reported for the first time. The reaction can be easily scaled up 200 times (100 mmol) without any degasification and purification of reactants; this facilitates the practical application in routine synthesis.
- Yuen, On Ying,So, Chau Ming,Man, Ho Wing,Kwong, Fuk Yee
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supporting information
p. 6471 - 6476
(2016/05/09)
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- Direct Transformation of Esters into Arenes with 1,5-Bifunctional Organomagnesium Reagents
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A direct transformation of carboxylic acid esters into arenes with 1,5-bifunctional organomagnesium reagents is described. This efficient and practical method enables the one-step defunctionalization of various carboxylic acid esters to prepare benzene, anthracene, tetracene, and pentacene derivatives. A double nucleophilic addition of the 1,5-organodimagnesium reagent to the ester is followed by an immediate 1,4-elimination reaction that leads to the direct [5+1] formation of a new aromatic ring.
- Link, Achim,Fischer, Christian,Sparr, Christof
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supporting information
p. 12163 - 12166
(2015/10/12)
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- Side substituent dependence of photophysical properties of 9-arylanthracene-based π-conjugates
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Three new 9-arylanthracene-based π-conjugated derivatives with different side substituent (methyl, methoxy, and hexyloxy) were synthesized using Heck coupling/ HornerEmmons reaction in good yields (7278%) and their photophysical properties investigated. T
- Jana, Debabrata,Ghorai, Binay K.
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- Synthesis, characterization and X-ray structures of N-heterocyclic carbene palladium complexes based on calix[4]arenes: Highly efficient catalysts towards Suzuki-Miyaura cross-coupling reactions
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A new series of calix[4]arene supported N-heterocyclic carbene palladium complexes were developed and fully characterized. A mono-substituted calix[4]arene was prepared through conventional procedures, following with the attachment of imidazolyl derivative groups to compose the precursors of novel NHCs ligands. Undergoing the alkylation with n-butylbromide and corresponding metallation with palladium and pyridine, original complexes were obtained. After a full characterization in solution and solid state, the evaluation of catalytic activity was taken out in Suzuki-Miyaura cross-coupling reactions, which revealed good performances.
- Ren, Hui,Xu, Yong,Jeanneau, Erwann,Bonnamour, Isabelle,Tu, Tao,Darbost, Ulrich
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p. 2829 - 2837
(2014/04/17)
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- Suzuki-Miyaura cross-coupling of bulky anthracenyl carboxylates by using pincer nickel N-heterocyclic carbene complexes: An efficient protocol to access fluorescent anthracene derivatives
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A series of fluorescent (hetero)-aryl substituted anthracene derivatives were readily accessible from the corresponding bulky anthracen-9-yl carboxylates via Suzuki-Miyaura cross-coupling reactions by using pincer nickel N-heterocyclic carbene complex 1 even at the catalyst loading as low as 0.1 mol% in the presence of catalytic amounts of PCy3.
- Xu, Mizhi,Li, Xingbao,Sun, Zheming,Tu, Tao
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supporting information
p. 11539 - 11541
(2013/12/04)
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- Synthesis of annulated arenes and heteroarenes involving lewis acid-mediated regioselective annulation of unsymmetrical 1,2-(Diaryl/ diheteroarylmethine)dipivalates
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A ZnBr2-mediated regioselective annulation of unsymmetrical 1,2-diarylmethinedipivalates in DCM at room temperature led to the formation of annulated arenes and heteroarenes. The annulation of the dipivalate proceeds through the intermediacy of
- Sivasakthikumaran, Ramakrishnan,Nandakumar, Meganathan,Mohanakrishnan, Arasambattu K.
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p. 9053 - 9071,19
(2012/12/12)
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- Dramatic effect of the gelling cation on the catalytic performances of alginate-supported palladium nanoparticles for the Suzuki-Miyaura reaction
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This work describes the preparation and characterization of a library of alginate-supported palladium nanoparticles together with their catalytic capabilities to promote the Suzuki-Miyaura reaction. Using the chelating properties of the carboxylate functions of the alginate matrix a series of Ca, Ba, Mn, Zn, Ni, Ce, Cu, and Co alginate gels were first prepared and then reacted with Pd2+ salts. Partial exchange of metal cations followed by Pd reduction into palladium nanoparticles and supercritical CO2 drying generated a panel of bimetallic alginate aerogels. Physical characterizations of these materials showed a significant influence of both the gelling metal nature and the Pd loading on surface areas and nanoparticles size. A comparative study of the catalytic performances of these heterogeneous catalytic systems is then reported for the Suzuki-Miyaura reaction. This study highlighted the superior performances of palladium nanoparticles supported on copper-alginate aerogels. This heterogeneous catalyst showed high catalytic activities as illustrated by a TOF value of 10 s-1 and a TON value close to 106. The robustness of the catalyst allowed several reuses with no significant loss of activity or metal leaching.
- Chtchigrovsky, Melanie,Lin, Yi,Ouchaou, Kahina,Chaumontet, Manon,Robitzer, Mike,Quignard, Francoise,Taran, Frederic
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experimental part
p. 1505 - 1510
(2012/07/31)
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- Tweezers-like aromatic molecules and their luminescent properties depending on the structures
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Di(hydroxyphenyl)pyrimidine with two anthryl substituents 1a was synthesized and characterized by X-ray crystallography and NMR spectroscopy. The molecule prefers 'U'-shaped conformation supported by intramolecular O-H?N hydrogen bonds in the solid state
- Suzaki, Yuji,Tsuchido, Yoshitaka,Osakada, Kohtaro
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supporting information; experimental part
p. 3883 - 3885
(2011/08/09)
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- Preparation of benzocyclobutenols by low temperature reaction of ketone enolates with benzynes
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The reaction of benzynes, generated from halobenzenes with lithium tetramethylpipiperide (LTMP) at -40 to -78°C, with ketone enolates affords benzocyclobutenols in fair to good yields.
- Tripathy, Sasmita,Reddy, Ranga,Durst, Tony
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p. 997 - 1002
(2007/10/03)
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- Remote substituent effects on the reactivity of 9-aryl- and 9,10-diarylanthracene radical cations with anions and amines
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Radical cations of 9-aryl- and 9,10-diarylanthracenes with substituents on the 4 position of the aryl rings (PA-X?+ and DPA-X?+, respectively) have been generated by photoionization in acetonitrile. Their reactivity with n-butylamine (n-BuNH2) and 1,4-diazabicyclo[2.2.2]octane (DABCO) and a number of anions (CH3CO2-, Br-, CN-, N3-) has been studied using nanosecond laser flash photolysis. Reactions proceed by electron transfer and/or nucleophilic addition. Using PA-X and DPA-X as chemical probes, simple criteria are established that allow one mechanistic pathway to be distinguished from another. When electron transfer is thermodynamically feasible, this pathway dominates (e.g., DABCO and azide). For endothermic electron transfer, addition is not necessarily the preferred ultimate reaction pathway and an inner sphere process (addition/ homolysis) can compete. In these cases other, criteria including steric factors and the strength of the incipient bond become important. Simple kinetic criteria and an approach to estimate the thermochemistry of the addition process are developed. It is clear from these studies that reactivity trends in the radical cation chemistry cannot be generalized as easily as those in carbocation chemistry. This has some implications concerning the development and utility of "clock" reactions in radical cation chemistry.
- Workentin, Mark S.,Parker, Vernon D.,Morkin, Tracy L.,Wayner, Danial D. M.
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p. 6503 - 6512
(2007/10/03)
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