620-93-9Relevant academic research and scientific papers
Studies on the amination of aryl chlorides with a monoligated palladium catalyst: Kinetic evidence for a cooperative mechanism
Jimeno, Ciril,Christmann, Ute,Escudero-Adan, Eduardo C.,Vilar, Ramon,Pericas, Miquel A.
, p. 16510 - 16516 (2012)
Combined spectroscopic, crystallographic, and kinetic studies of the mechanism of aromatic amination with the efficient dinuclear Pd precatalyst [Pd2Cl(μ-Cl)PtBu2(Bph-Me)] (Bph-Me=2′-methyl-[1, 1'-biphenyl]-2-yl) have revealed overlapping, yet cooperative, mechanistic scenarios, the relative weights of which are strongly influenced by the products formed as the reaction proceeds. The stability and evolution of the precatalyst in solution has been studied and several metalation pathways that point to a single monoligated intermediate have been identified. Our work sheds light on the nature of the catalytic species involved in the process and on the structure of the corresponding catalytic network. Two cycles for catalytic amination: Combined spectroscopic, crystallographic, and kinetic studies on the amination of p-chlorotoluene with p-toluidine with a monoligated Pd catalyst have revealed overlapping, yet cooperative, mechanistic scenarios, the relative weights of which are strongly influenced by the products formed as the reaction proceeds (see scheme; L=2′-methyl-[1,1'-biphenyl]-2-yl).
Electron Transfer Rate Maxima at Large Donor-Acceptor Distances
Kuss-Petermann, Martin,Wenger, Oliver S.
, p. 1349 - 1358 (2016)
Because of their low mass, electrons can transfer rapidly over long (>15 ?) distances, but usually reaction rates decrease with increasing donor-acceptor distance. We report here on electron transfer rate maxima at donor-acceptor separations of 30.6 ?, observed for thermal electron transfer between an anthraquinone radical anion and a triarylamine radical cation in three homologous series of rigid-rod-like donor-photosensitizer-acceptor triads with p-xylene bridges. Our experimental observations can be explained by a weak distance dependence of electronic donor-acceptor coupling combined with a strong increase of the (outer-sphere) reorganization energy with increasing distance, as predicted by electron transfer theory more than 30 years ago. The observed effect has important consequences for light-to-chemical energy conversion.
Improved Buchwald-Hartwig Amination by the Use of Lipids and Lipid Impurities
Bayer, Annette,Gevorgyan, Ashot,Hopmann, Kathrin H.
supporting information, (2021/11/12)
The development of green Buchwald-Hartwig aminations has long been considered challenging, due to the high sensitivity of the reaction to the environment. Here we show that food-grade and waste vegetable oils, triglycerides originating from animals, and natural waxes can serve as excellent green solvents for Buchwald-Hartwig amination. We further demonstrate that amphiphiles and trace ingredients present in triglycerides as additives have a decisive effect on the yields of Buchwald-Hartwig aminations.
Mechanochemical synthesis of aromatic sulfonamides
Iaroshenko, Viktor O.,Mkrtchyan, Satenik
supporting information, p. 11029 - 11032 (2021/11/03)
A three-component Pd-catalysed aminosulfonylation reaction of K2S2O5 and amine with aryl bromides or aromatic carboxylic acids was developed. This strategy was developed to utilise mechanical energy and accommodate primary as well as secondary aliphatic and aromatic amines to provide a new shortcut to a wide range of sulfonamides. Studies on the scope and limitations of the reaction indicated its tolerance of a vast range of functional groups and many structural patterns. The reactions were scaled up to gram quantities.
Temperature-Dependent Effects of Alkyl Substitution on Diarylamine Antioxidant Reactivity
Shah, Ron,Poon, Jia-Fei,Haidasz, Evan A.,Pratt, Derek A.
, p. 6538 - 6550 (2021/05/29)
Alkylated diphenylamines are among the most efficacious radical-trapping antioxidants (RTAs) for applications at elevated temperatures since they are able to trap multiple radical equivalents due to catalytic cycles involving persistent diphenylnitroxide and diphenylaminyl radical intermediates. We have previously shown that some heterocyclic diarylamine RTAs possess markedly greater efficacy than typical alkylated diphenylamines, and herein, report on our efforts to identify optimal alkyl substitution of the scaffold, which we had found to be the ideal compromise between reactivity and stability. Interestingly, the structure-activity relationships differ dramatically with temperature: para-alkyl substitution slightly increased reactivity and stoichiometry at 37 and 100 °C due to more favorable (stereo)electronic effects and corresponding diarylaminyl/diarylnitroxide formation, while ortho-alkyl substitution slightly decreased both reactivity and stoichiometry. No such trends were evident at 160 °C; instead, the compounds were segregated into two groups based on the presence/absence of benzylic C-H bonds. Electron spin resonance spectroscopy indicates that increased efficacy was associated with lesser diarylnitroxide formation, and deuterium-labeling suggests that this is due to abstraction of the benzylic H atom, precluding nitroxide formation. Computations predict that this reaction path is competitive with established fates of the diarylaminyl radical, thereby minimizing the formation of off-cycle products and leading to significant gains in high-temperature RTA efficacy.
Diaromatic ring amide compound and application thereof
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Paragraph 0101; 0102; 0104-0106, (2021/07/01)
The invention relates to a diarylcyclic amide compound and application thereof. According to the invention, a high-purity solid can be obtained mainly by using the traditional recrystallization and column separation, the solid can be converted into corresponding diarylamine at high yield, especially high-purity liquid diarylcyclic secondary amine can be easily and conveniently obtained, and a high-purity organic semiconductor can be produced by the high-purity secondary amine on a large scale, and can be used in OPV or OLED devices. The chemical formula of the compound is shown in the specification, wherein R1 and R2 are H, D, F, or alkyl, alkoxy, fluoroalkyl, silyl, cycloalkyl, cycloalkoxy,-CN, -NO2 or phenyl with the carbon atom number smaller than 12; the dotted line is an oxygen atom, a sulfur atom, a silicon atom, a nitrogen atom, a carbon atom or a chemical bond for connecting two benzene rings or is nothing at all; and z is a protecting group and is selected from carbobenzoxy, t-butyloxycarbonyl, fluorene methoxycarbonyl, allyloxycarbonyl, trimethylsilylethoxycarbonyl, methoxycarbonyl, ethoxycarbonyl, phthaloyl, p-toluenesulfonyl, trifluoroacetyl, benzoyl, trityl, 2, 4-dimethoxybenzyl, p-methoxybenzyl and benzyl.
Cu(I)–N-heterocyclic carbene-catalyzed base free C–N bond formation of arylboronic acids with amines and azoles
Zhang, Maoyuan,Xu, Zengbing,Shi, Dabin
, (2020/12/25)
A new N-heterocyclic carbene (NHC) precursor of imidazolium chloride and its corresponding Cu(I)–NHC complex 1 was synthesized. The complex 1 was found to be a highly effective catalyst for Chan-Evans-Lam coupling of arylboronic acid with amines and azoles (including imidazole, pyrazole and triazole), without addition of base at room temperature. Various substituents on three substrates can be tolerated, giving the desired coupling products in good to excellent yields (62–94%). The method is practical and offers an alternative to the corresponding copper-catalyzed Chan-Evans-Lam process for the construction of C–N bonds.
Electrochemical Reductive Arylation of Nitroarenes with Arylboronic Acids
Wang, Dan,Wan, Zhaohua,Zhang, Heng,Alhumade, Hesham,Yi, Hong,Lei, Aiwen
, p. 5399 - 5404 (2021/10/20)
The synthesis of diarylamine is extremely important in organic chemistry. Herein, a novel electrochemical reductive arylation of nitroarenes with arylboronic acids was developed. A variety of diarylamines were synthesized without the need for transition-metal catalysts. The reaction could be scaled up efficiently in a flow cell and several derivatization reactions were carried out smoothly. Cyclic voltammetry experiments and mechanism studies showed that acetonitrile, formic acid, and triethyl phosphite all played a role in promoting this reductive arylation transformation.
Selective primary aniline synthesis through supported Pd-catalyzed acceptorless dehydrogenative aromatization by utilizing hydrazine
Lin, Wei-Chen,Yamaguchi, Kazuya,Yatabe, Takafumi
supporting information, p. 6530 - 6533 (2021/07/07)
By utilizing hydrazine (N2H4) as the nitrogen source in the presence of a hydroxyapatite-supported Pd nanoparticle catalyst (Pd/HAP), various primary anilines can be selectively synthesized from cyclohexanonesviaacceptorless dehydrogenative aromatization. The strong nucleophilicity of N2H4and the stability of the hydrazone intermediates can effectively suppress the formation of the undesired secondary aniline byproducts.
Electron Push-Pull Effects on Intramolecular Charge Transfer in Perylene-Based Donor-Acceptor Compounds
Ahn, Mina,Kim, Min-Ji,Cho, Dae Won,Wee, Kyung-Ryang
, p. 403 - 413 (2020/12/23)
A series of asymmetric donor-acceptor (D-A) perylene-based compounds, 3-(N,N-bis(4′-(R)-phenyl)amino)perylene (Peri-DPA(R)), were successfully prepared to explore their intramolecular charge transfer (ICT) properties. To induce ICT between the donor and acceptor, diphenylamine (DPA) derivatives (electron donor units) with the same functional groups (R = CN, F, H, Me, or OMe) at both para positions were linked to the C-3 position of perylene to produce five Peri-DPA derivatives. A steady-state spectroscopy study on Peri-DPA(R)s exhibited a progressively regulated ICT trend consistent with the substituent effect as it progressed from the electron-withdrawing group to the electron-donating group. In particular, a comparative study using a D-A-D (donor-acceptor-donor) system demonstrated that not only the electron push-pull substituent effect but also subunit combinations influence photophysical and electrochemical properties. The different ICT characters observed in Lippert-Mataga plots of D-A(CN) and D-A-D(CN) (CN-substituted D-A and D-A-D) led to the investigation on whether ICT emission of two systems with differences in subunit combinations is of the same type or of a different type. The femtosecond transient absorption (fs-TA) spectroscopic results provided direct evidence of ICT origin and confirmed that D-A(CN) and D-A-D(CN) exhibited the same transition mix of ICT (from donor to acceptor) and reverse ICT (rICT, from arylamine to CN unit). Density functional theory (DFT)/TD-DFT calculations support the presence of ICT for all five compounds, and the experimental observations of rICT presented only for CN-substituted compounds.
