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.
Nickel-catalyzed deallylation of aryl allyl ethers with hydrosilanes
Ding, Guangni,Fan, Sijie,Wang, Jingyang,Wang, Yu,Wu, Xiaoyu,Xie, Xiaomin,Yang, Liqun,Zhang, Zhaoguo
supporting information, (2021/09/28)
An efficient and mild catalytic deallylation method of aryl allyl ethers is developed, with commercially available Ni(COD)2 as catalyst precursor, simple substituted bipyridine as ligand and air-stable hydrosilanes. The process is compatible with a variety of functional groups and the desired phenol products can be obtained with excellent yields and selectivity. Besides, by detection or isolation of key intermediates, mechanism studies confirm that the deallylation undergoes η3-allylnickel intermediate pathway.
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.
Highly Efficient Oxidative Cyanation of Aldehydes to Nitriles over Se,S,N-tri-Doped Hierarchically Porous Carbon Nanosheets
Hua, Manli,Song, Jinliang,Huang, Xin,Liu, Huizhen,Fan, Honglei,Wang, Weitao,He, Zhenhong,Liu, Zhaotie,Han, Buxing
supporting information, p. 21479 - 21485 (2021/08/23)
Oxidative cyanation of aldehydes provides a promising strategy for the cyanide-free synthesis of organic nitriles. Design of robust and cost-effective catalysts is the key for this route. Herein, we designed a series of Se,S,N-tri-doped carbon nanosheets with a hierarchical porous structure (denoted as Se,S,N-CNs-x, x represents the pyrolysis temperature). It was found that the obtained Se,S,N-CNs-1000 was very selective and efficient for oxidative cyanation of various aldehydes including those containing other oxidizable groups into the corresponding nitriles using ammonia as the nitrogen resource below 100 °C. Detailed investigations revealed that the excellent performance of Se,S,N-CNs-1000 originated mainly from the graphitic-N species with lower electron density and synergistic effect between the Se, S, N, and C in the catalyst. Besides, the hierarchically porous structure could also promote the reaction. Notably, the unique feature of this metal-free catalyst is that it tolerated other oxidizable groups, and showed no activity on further reaction of the products, thereby resulting in high selectivity. As far as we know, this is the first work for the synthesis of nitriles via oxidative cyanation of aldehydes over heterogeneous metal-free catalysts.
A Molecular Iron-Based System for Divergent Bond Activation: Controlling the Reactivity of Aldehydes
Chatterjee, Basujit,Jena, Soumyashree,Chugh, Vishal,Weyhermüller, Thomas,Werlé, Christophe
, p. 7176 - 7185 (2021/06/30)
The direct synthesis of amides and nitriles from readily available aldehyde precursors provides access to functional groups of major synthetic utility. To date, most reliable catalytic methods have typically been optimized to supply one product exclusively. Herein, we describe an approach centered on an operationally simple iron-based system that, depending on the reaction conditions, selectively addresses either the C=O or C-H bond of aldehydes. This way, two divergent reaction pathways can be opened to furnish both products in high yields and selectivities under mild reaction conditions. The catalyst system takes advantage of iron's dual reactivity capable of acting as (1) a Lewis acid and (2) a nitrene transfer platform to govern the aldehyde building block. The present transformation offers a rare control over the selectivity on the basis of the iron system's ionic nature. This approach expands the repertoire of protocols for amide and nitrile synthesis and shows that fine adjustments of the catalyst system's molecular environment can supply control over bond activation processes, thus providing easy access to various products from primary building blocks.
One pot synthesis of aryl nitriles from aromatic aldehydes in a water environment
Chen, Qingqing,Han, Hongwei,Lin, Hongyan,Ma, Xiaopeng,Qi, Jinliang,Wang, Xiaoming,Yang, Yonghua,Zhou, Ziling
, p. 24232 - 24237 (2021/07/29)
In this study, we found a green method to obtain aryl nitriles from aromatic aldehyde in water. This simple process was modified from a conventional method. Compared with those approaches, we used water as the solvent instead of harmful chemical reagents. In this one-pot conversion, we got twenty-five aryl nitriles conveniently with pollution to the environment being minimized. Furthermore, we confirmed the reaction mechanism by capturing the intermediates, aldoximes.
Rodlike 4,6-diamino-1,3,5-triazine derivatives, effect of the core length on mesophase behavior and their application as LE-LCD device
Cao, Yu,Chang, Qing,Cheng, Xiaohong,Liu, Feng,Su, Fawu,Tan, Xiaoping
, (2021/11/16)
Three series of diaminotriazine derivatives with different core length have been synthesized, and the influence of the structural variation as well as the temperature on their mesophase behaviour were systematically investigated. With focus on the formation of CubI/Im3ˉm phase, multiple 2D/3D phases were discovered. Confirmed by polarized optical microscope, small/wide angle X-ray scattering, grazing incident small-angle X-ray scattering as well as molecular dynamics simulation, the results indicate that molecular curvature is critical to self-assembly structures. Moreover, the prerequisite for the formation of the CubI/Im3ˉm phase is intermediate molecular curvature on the surface of the micelle to allow the intercalation of the alkyl chains. Finally, the potentials for such compounds as light-emitting liquid crystal display (LE-LCD) device has been initially demonstrated.
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.
Synthetic method of p-hydroxybenzonitrile
-
, (2021/01/30)
The invention discloses a synthesis method of p-hydroxybenzonitrile, which comprises the following steps: carrying out diazotization reaction on p-hydroxyaniline to form a diazo compound, and reactingthe diazo compound with cuprous chloride and sodium cyanide to obtain the p-hydroxybenzonitrile. The p-hydroxyaniline is obtained by hydrogen reduction of p-nitrosophenol, and the p-nitrosophenol isobtained by nitrosation of phenol. The reaction temperature of each step is low, the reaction conditions are mild, and the reaction power consumption is greatly reduced. The reaction can be carried out by adopting a conventional reaction kettle, the equipment requirement is low, and the investment is small. According to the method, a dehydrating agent and filler are not used, only a small amount of catalyst is used, meanwhile, the catalyst can be recycled, the solid waste amount is small, only a small amount of solid catalyst is generated, and no difficult-to-treat wastewater is generated.
