767-00-0Relevant articles and documents
Bis(4-cyanophenyl) phenyl phosphate as viscosity reducing comonomer for phthalonitrile resins
Terekhov,Aleshkevich,Afanaseva,Nechausov,Babkin,Bulgakov,Kepman,Avdeev
, p. 34 - 41 (2019)
Bis(4-cyanophenyl) phenyl phosphate (CPP) is introduced for the first time as a viscosity reducing comonomer for phthalonitrile resins. In comparison to the common phthalonitrile resins, the blends of CPP with 4,4′-[benzene-1,3-diylbis(oxy)]diphthalonitrile demonstrated advanced processing properties suitable for cost-effective injection processing (η as low as to 180 mPa?s at 100 °C). Thermal copolymerization was performed indicating complete inclusion of bis-benzonitrile CPP into the phthalonitrile network resulting in formation of thermosets with great thermal performance. Hydrolysis of CPP at pH 4, 7, and 10 was studied to confirm its suitability as a reactive diluent for phthalonitrile. Conversion vs. time plots were obtained via HPLC analysis, and pseudo-first order rate constants were determined in the range of 25–80 °C. The activation parameters were calculated from the Arrhenius equation.
A highly photosensitive covalent organic framework with pyrene skeleton as metal-free catalyst for arylboronic acid hydroxylation
Chen, Ying,Huo, Jianqiang,Zhang, Yubao
, (2022/03/16)
Covalent organic frameworks (COFs) have been widely utilized in metal-free photocatalytic synthesis base on their excellent properties such as super conjugation, porosity and stability. In this work, we synthesized a new COF material using 1,3,6,8-Tetrakis (p-formylphenyl)pyrene (TFPPy) and 2,2′-Dimethylbenzidine (DMBZ) as basic units through Schiff base condensation reaction. The new COF (TF-DM COF) was applied as metal-free catalyst for hydroxylation of arylboronic acids. The results indicated that the extended π conjugation of COFs enhanced the absorption of visible light, and the large porosity (BET surface area: 113.782 m2g?1) accelerated the reaction rate. Good recyclability enables it with multiple applications, which result in a great reducing of the cost. This study reports that TF-DM COF has a broad application prospect as a new generation of metal-free photocatalysts for organic conversions.
Nucleofugality hierarchy, in the aminolysis reaction of 4-cyanophenyl 4-nitrophenyl carbonate and thionocarbonate. Experimental and theoretical study
Aliaga, Margarita E.,Cornejo, Patricio,Montecinos, Rodrigo,Pavez, Paulina,Santos, José G.
, p. 11495 - 11505 (2021/07/12)
Nucleophilic substitution reactions of the title compounds have been investigated with a series of secondary alicyclic amines in several solvents. The solvent, amine, and electrophilic group effects on kinetics, mechanism and nucleofugality hierarchy are discussed from experimental and theoretical studies. These studies show the mechanistic dependence on the solvent polarity; the theoretical results indicate that the relative polarization of the reactive centres (CO and CS) and the stabilization of the nucleofuges are the main factors in the control of the product distribution.
Dehydration of aldoximes to nitriles using trichloroacetonitrile without catalyst
Ma, Xiaoyun,Liu, Dan,Chen, Zhengjian
, p. 3261 - 3266 (2021/06/30)
Trichloroacetonitrile has been found to be an efficient dehydrating agent for a range of aldoximes including aromatic and heterocyclic aldoxime yielding the corresponding nitriles in moderate to good yields. The dehydration reactions can take place in non-acetonitrile media without the aid of a metal catalyst. In addition, it has been confirmed that trichloroacetonitrile was converted into trichloroacetamide in the reaction.
Substituent and Surfactant Effects on the Photochemical Reaction of Some Aryl Benzoates in Micellar Green Environment?
Siano, Gastón,Crespi, Stefano,Bonesi, Sergio M.
, p. 1298 - 1309 (2021/05/07)
In this study, we carried out preparative and mechanistic studies on the photochemical reaction of a series of p-substituted phenyl benzoates in confined and sustainable micellar environment. The aim of this work is mainly focused to show whether the nature of the surfactant (ionic or nonionic) leads to noticeable selectivity in the photoproduct formation and whether the electronic effects of the substituents affect the chemical yields and the rate of formation of the 5-substituted-2-hydroxybenzophenone derivatives. Application of the Hammett linear free energy relationship (LFER) on the rate of formation of benzophenone derivatives, on the lower energy band of the UV-visible absorption spectra of the aryl benzoates and 5-substituted-2-hydroxybenzophenone derivatives allows a satisfactory quantification of the substituent effects. Furthermore, UV-visible and 2D-NMR (NOESY) spectroscopies have been employed to measure the binding constant Kb and the location of the aryl benzoates within the hydrophobic core of the micelle. Finally, TD-DFT calculations have been carried out to estimate the energies of the absorption bands of p-substituted phenyl benzoates and 5-substituted-2-hydroxybenzophenone derivatives providing good linear correlation with those values measured experimentally.
Method for hydrolyzing diarylether compound to generate aryl phenol compound
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Paragraph 0096-0098, (2021/09/29)
The invention discloses a method for hydrolyzing a diarylether compound to generate an arylphenol compound. According to the method, visible light is utilized to excite a photosensitizer for catalysis. In a reaction solvent, the raw material in the formula (1) breaks a C (sp2)-O bond under the auxiliary action of acid, and hydrolysis is performed to obtain the bimolecular aryl phenol compounds in the formula (3) and the formula (4). The method can catalyze the reaction at room temperature, is green and environment-friendly, and is easy to operate; the universality is wide, the reaction yield is relatively high, and the tolerance of functional groups is strong; the synthesis method not only can realize small-scale hydrolysis conversion of various diarylether compounds, but also can realize hydrolysis of herbicidal ether, triclosan and a lignin template substrate, and even can realize large-scale hydrolysis of triclosan and the lignin template substrate to realize gram-level degradation. A new strategy is provided for recovering phenol derivatives through lignin hydrolysis, degrading pesticides and purifying wastewater containing a degerming agent or herbicide. The method has wide application prospect and use value.
Decarboxylative Hydroxylation of Benzoic Acids
Ritter, Tobias,Su, Wanqi,Xu, Peng
, p. 24012 - 24017 (2021/10/06)
Herein, we report the first decarboxylative hydroxylation to synthesize phenols from benzoic acids at 35 °C via photoinduced ligand-to-metal charge transfer (LMCT)-enabled radical decarboxylative carbometalation. The aromatic decarboxylative hydroxylation is synthetically promising due to its mild conditions, broad substrate scope, and late-stage applications.
Alkylsulfenyl thiocarbonates: precursors to hydropersulfides potently attenuate oxidative stress
Aggarwal, Sahil C.,Khodade, Vinayak S.,Paolocci, Nazareno,Pharoah, Blaze M.,Toscano, John P.
, p. 8252 - 8259 (2021/06/22)
The recent discovery of the prevalence of hydropersulfides (RSSH) species in biological systems suggests their potential roles in cell regulatory processes. However, the reactive and transient nature of RSSH makes their study difficult, and dependent on the use of donor molecules. Herein, we report alkylsulfenyl thiocarbonates as a new class of RSSH precursors that efficiently release RSSH under physiologically relevant conditions. RSSH release kinetics from these precursors are tunable through electronic modification of the thiocarbonate carbonyl group's electrophilicity. In addition, these precursors also react with thiols to release RSSH with a minor amount of carbonyl sulfide (COS). Importantly, RSSH generation by these precursors protects against oxidative stress in H9c2 cardiac myoblasts. Furthermore, we demonstrate the ability of these precursors to increase intracellular RSSH levels.
Copper-promoted cyanation of aryl iodides with N,N-dimethyl aminomalononitrile
Liu, Si-Zhan,Li, Jing,Xue, Cao-Gen,Xu, Xue-Tao,Lei, Lin-Sheng,Huo, Chen-Yu,Wang, Zhen,Wang, Shao-Hua
supporting information, (2021/02/01)
A copper-promoted cyanation of aryl iodides has been successfully developed by using N,N-dimethyl aminomalononitrile as the cyanide source with moderate toxicity and better stability. This reaction features broad substrate scope, excellent reaction yields, readily available catalyst, and simple reaction conditions.
Photocatalytic Reductive C-O Bond Cleavage of Alkyl Aryl Ethers by Using Carbazole Catalysts with Cesium Carbonate
Yabuta, Tatsushi,Hayashi, Masahiko,Matsubara, Ryosuke
, p. 2545 - 2555 (2021/02/01)
Methods to activate the relatively stable ether C-O bonds and convert them to other functional groups are desirable. One-electron reduction of ethers is a potentially promising route to cleave the C-O bond. However, owing to the highly negative redox potential of alkyl aryl ethers (Ered -2.6 V vs SCE), this mode of ether C-O bond activation is challenging. Herein, we report the visible-light-induced photocatalytic cleavage of the alkyl aryl ether C-O bond using a carbazole-based organic photocatalyst (PC). Both benzylic and non-benzylic aryl ethers underwent C-O bond cleavage to form the corresponding phenol products. Addition of Cs2CO3 was beneficial, especially in reactions using a N-H carbazole PC. The reaction was proposed to occur via single-electron transfer (SET) from the excited-state carbazole to the substrate ether. Interaction of the N-H carbazole PC with Cs2CO3 via hydrogen bonding exists, which enables a deprotonation-assisted electron-transfer mechanism to operate. In addition, the Lewis acidic Cs cation interacts with the substrate alkyl aryl ether to activate it as an electron acceptor. The high reducing ability of the carbazole combined with the beneficial effects of Cs2CO3 made this otherwise formidable SET event possible.
