13633-25-5Relevant academic research and scientific papers
Novel quaternary ammonium functional addition-type norbornene copolymer as hydroxide-conductive and durable anion exchange membrane for direct methanol fuel cells
He, Xiaohui,Liu, Jingyin,Zhu, Hongyu,Zheng, Yan,Chen, Defu
, p. 63215 - 63225 (2015)
Novel quaternary ammonium functional addition-type norbornene copolymers (QCnP(BN/PhBN), n = 1, 6, 10, 12) with different alkyl side chain length comb-shaped structures or different contents of 2-(4-phenyl-butoxymethy-lene)-5-norbornene (PhBN) (22-77%) are synthesized via copolymerization of functionalized norbornenes, and their corresponding hydroxide-conductive anion exchange membranes (AEMs) with effective hydrophilic-hydrophobic separation are prepared and confirmed by TEM or SEM. The achieved AEMs show high ion exchange capacity (1.83 mmol g-1), as well as low methanol permeability (1.97-20.4 × 10-7 cm2 s-1), which are lower than that of Nafion. The ionic conductivity increases with the operation temperature increasing and is observed up to 4.14 × 10-3 S cm-1. The AEMs exhibit excellent dimensional stability with a swelling degree in plane between 0.9-3.3% and good chemical stability under 6 M NaOH solution even after a month. Membrane electrode assembly (MEA) is fabricated by using the alkalized QC12P(BN/PhBN)-77 as the AEM and tested in an alkaline direct methanol fuel cell. The open circuit voltage (OVC) of 0.54 V and the maximum current density of 66 mW cm-2 are achieved at 80 °C, respectively.
Microwave accelerated facile synthesis of fused polynuclear hydrocarbons in dry media by intramolecular Friedel-Crafts alkylation
Kurteva, Vanya B.,Santos, Antonio Gil,Afonso, Carlos A.M.
, p. 514 - 523 (2004)
Fused polynuclear tetrahydro arenes are synthesised in a fast, simple, high yielding and regiospecific procedure by an intramolecular Friedel-Crafts alkylation in dry media under microwave irradiation of the corresponding 1-bromo-4-arylbutanes immobilised on silica. The observed reactivity is rationalised by molecular modelling studies which suggest the occurence of a concerted mechanism.
Cs2CO3 promoted O-alkylation of alcohols for the preparation of mixed alkyl carbonates
Chu,Dueno,Kyung Woon Jung
, p. 1847 - 1850 (1999)
The presence of cesium carbonate and tetrabutylammonium iodide (TBAI) facilitated efficient O-alkylation of alcohols with alkyl halides, giving rise to the exclusive formation of mixed alkyl carbonates. The cesium effect was also examined comparatively with other alkali carbonates.
Nucleophilic substitution reactions of unbranched alkyl amines using triazine reagents
Kitamura, Masanori,Kitaoka, Yuki,Fujita, Hikaru,Kunishima, Munetaka
, (2022/03/02)
Since amines are present in many organic, biological, and drug molecules, a strategy of synthesizing desired compounds by nucleophilic substitution reactions of these amines is very attractive. By using triazine reagents, we have found that nucleophilic substitution reactions of unbranched alkyl amines via morpholine derivatives are feasible. This method can be performed under milder reaction conditions than those in previously reported methods.
Regiodivergent Conversion of Alkenes to Branched or Linear Alkylpyridines
Kim, Minseok,Shin, Sanghoon,Koo, Yejin,Jung, Sungwoo,Hong, Sungwoo
supporting information, p. 708 - 713 (2022/01/20)
Herein we report a practical protocol for the visible-light-induced regiodivergent radical hydropyridylation of unactivated alkenes using pyridinium salts. This approach provides a unified synthetic platform to control the regioselectivity of the synthesis of linear or branched C4-alkylated pyridines. A remarkable selectivity switch from the anti-Markovnikov to the Markovnikov product can be achieved by the addition of tetrabutylammonium bromide. The versatility of this protocol is further demonstrated based on the late-stage functionalization in pharmaceuticals.
Preparation method for p-phenylbutoxybenzoic acid
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, (2019/11/04)
The invention provides a preparation method for p-phenylbutoxybenzoic acid, belonging to the field of organic synthesis. According to the invention, palladium-based catalytic coupling is adopted, andthe Grignard reaction and the Friedel-Craft reaction are avoided, thereby avoiding the production of blue-green copper ion wastewater and generation of a large amount of acidic wastewater due to usageof aluminum trichloride; the preparation method of the invention is friendly to environment, simple in synthesis route and high in the yield of each step; and halogeno-benzene is used for replacing more expensive phenylmagnesium bromide and used as a starting material, so the preparation cost of p-phenylbutoxybenzoic acid is lowered. The p-phenylbutoxybenzoic acid obtained in the invention has good crystal form, high purity and good solubility. The data of embodiments of the invention show that the total yield of p-phenylbutoxybenzoic acid prepared in the invention is 60% or above, and the HPLC purity of p-phenylbutoxybenzoic acid is 99.9% or above.
Synthesis method of intermediate 1-bromo-4-phenylbutane
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Paragraph 0008; 0019; 0020; 0029, (2019/01/07)
The invention discloses a synthesis method of intermediate 1-bromo-4-phenylbutane. According to the method, 4-phenyl butanol, hydrobromic acid, POM-C3N4, melamine, phosphorous acid, ammonia water andMoO3 are taken as main raw materials, wherein the mass ratio of the 4-phenyl butanol to the hydrobromic acid is equal to 5 to 22; the molar ratio of the phosphorous acid to the ammonia water to the MoO3 is equal to 10 to 21 to 20, and the mass ratio of the C3N4 to P2Mo5 is equal to 5 to 1. According to the synthesis process provided by the invention, the 4-phenyl butanol and the hydrobromic acid are enabled to be subjected to a bromination reaction in presence of the catalyst POM-C3N4 so as to obtain the 1-bromo-4-phenylbutane. The traditional method uses concentrated sulfuric acid for bromination, so that a very serious carbonization phenomenon is caused, and the yield of brominated products is very low; after the POM-C3N4 heteroacid catalyst is adopted, the reaction is mild under the condition of reflux, and the yield is high; the obtained product is high in purity and simpler in aftertreatment.
Halogenation through Deoxygenation of Alcohols and Aldehydes
Chen, Jia,Lin, Jin-Hong,Xiao, Ji-Chang
supporting information, p. 3061 - 3064 (2018/05/28)
An efficient reagent system, Ph3P/XCH2CH2X (X = Cl, Br, or I), was very effective for the deoxygenative halogenation (including fluorination) of alcohols (including tertiary alcohols) and aldehydes. The easily available 1,2-dihaloethanes were used as key reagents and halogen sources. The use of (EtO)3P instead of Ph3P could also realize deoxy-halogenation, allowing for a convenient purification process, as the byproduct (EtO)3Pa?O could be removed by aqueous washing. The mild reaction conditions, wide substrate scope, and wide availability of 1,2-dihaloethanes make this protocol attractive for the synthesis of halogenated compounds.
Substrate and Catalyst Effects in the Enantioselective Copper-Catalysed C–H Insertion Reactions of α-Diazo-β-oxo Sulfones
Shiely, Amy E.,Clarke, Leslie-Ann,Flynn, Christopher J.,Buckley, Aoife M.,Ford, Alan,Lawrence, Simon E.,Maguire, Anita R.
supporting information, p. 2277 - 2289 (2018/06/04)
Excellent enantioselectivities of up to 98 % ee are achieved by employing the copper-bis(oxazoline)-NaBARF catalyst system in the C–H insertion reactions of α-diazo-β-oxo sulfones. The influence of variation of the bis(oxazoline) ligand, copper salt, additive and substrate on both the efficiency and the enantioselectivities of these intramolecular C–H insertion reactions has been explored. Optimum enantioselectivities are achieved with phenyl and diphenyl ligands across the substrate series.
Bent-core mesogens with an aromatic unit at the terminal position
Bajzíková, Kvetoslava,Svoboda, Ji?í,Novotná, Vladimíra,Pociecha, Damian,Gorecka, Ewa
supporting information, p. 4672 - 4679 (2017/07/10)
Bent-core liquid crystals with a naphthalene central unit and an aromatic ring at the terminal position of molecular tails were synthesised with the aim of enhancing nanosegregation. It was found that the length of the spacer between the rigid core and the terminal aromatic moiety had a profound influence on the liquid crystal polymorphism. The homologues with short spacers exhibited nematic and columnar phases, whereas the homologue with long spacers exhibited a tilted lamellar phase with a liquid-like in-plane order, indicating an unusual morphology of the densely packed toroidal objects. The morphology can be changed to twisted ribbons by small additives adsorbed on the membrane surface. This is the first example of twisted ribbons constructed by a lamellar system with no long-range in-plane order.
