- Aqueous microwave-assisted synthesis of non-interpenetrated metal-organic framework for room temperature cycloaddition of CO2 and epoxides
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A multilinker non-interpenetrated metal-organic framework, UMCM-15, was synthesized by using microwave power as an alternative energy-efficient tool for the first time. The synergistic catalytic activity, when combined with a co-catalyst containing a strongly nucleophilic anion, was studied in the solventless room temperature cycloaddition between epoxides and CO2. Unlike previous reports on UMCM-15 synthesized in the high-boiling solvent dimethylformamide, low boiling water/ethanol mixture was used as the solvent herein. This approach holds potential as a sustainable green methodology. Crystal formation during the microwave-assisted (MW) synthesis was monitored at certain time intervals. The favorable role of non-interpenetrated pillared structures in promoting room temperature CO2-epoxide cycloaddition reactions was explained by comparing the catalytic efficiency of the three-linker extended pillar-layered non-interpenetrated UMCM-15 with its analogous pillared structures built from two- and three-fold interpenetrated ([Zn2(BDC)2(4,4′-bipy)] and [Zn2(NDC)2(4,4′-bipy)]) catalytic systems with a single dicarboxylate linker. The efficacy of the microwave-assisted UMCM-15(M) catalyst in cycloaddition reactions was proved by comparing the catalytic activity of UMCM-15(M) with that of the congener made by solvothermal synthesis, UMCM-15(S). In addition, a plausible mechanism for the synergistic operation of the Lewis acid sites and nucleophiles was suggested.
- Babu, Robin,Kim, Seol-Hee,Kathalikkattil, Amal Cherian,Kuruppathparambil, Roshith Roshan,Kim, Dong Woo,Cho, Sung June,Park, Dae-Won
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Read Online
- Two Cu(II)-organic frameworks: Effective CO2 fixation and protective activity on the motor function after stroke by increasing neural stem cells differentiation
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In the present research, two novel metal–organic frameworks (MOFs) containing Cu(II) ions as nodes {[Cu(L)]·2DMF·2H2O}n (1) and {[(CH3)2NH2][Cu2(L)(H2O)PO4]·2DMF}
- Ye, Qing,Zhang, Li,Shao, Zhou-Li,Zhang, Wei,Li, Chao,Ye, Xiang-Ming
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Read Online
- Photo-on-Demand Base-Catalyzed Phosgenation Reactions with Chloroform: Synthesis of Arylcarbonate and Halocarbonate Esters
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Carbonate esters are utilized as solvents and reagents for C1 building blocks in organic synthesis. This study reports a novel photo-on-demand in situ synthesis of carbonate esters with CHCl3 solutions containing a mixture of an aromatic or haloalkyl alcohol having relatively high acidity, and an organic base. We found that the acid-base interaction of the alcohol and base in the CHCl3 solution plays a key role in enabling the photochemical reaction. This reaction allows practical syntheses of diphenyl carbonate derivatives, haloalkyl carbonates, and polycarbonates, which are important chemicals and materials in industry.
- Dai, Namin,Eda, Kazuo,Harada, Hidefumi,Hashimoto, Yuka,Hosokawa, Sasuga,Kakiuchi, Toshifumi,Liang, Fengying,Okazoe, Takashi,Suzuki, Yuto,Tana, Gegen,Tsuda, Akihiko
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p. 9811 - 9819
(2021/07/20)
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- Fluorodesulfurization of Thionobenzodioxoles with Silver(I) Fluoride
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Difluorobenzodioxole is an important functional group found in both pharmaceuticals and agrochemicals. The late-stage introduction of this functional group is challenged by typical fluorination conditions of HF and strong oxidants. Here, we demonstrate that a range of difluorobenzodioxoles can be prepared from catechols in two steps through conversion into thionobenzodioxoles, followed by desulfurative fluorination with silver(I) fluoride. These mild reaction conditions are compatible with a variety of functional groups and enable access to a range of functionalized difluorobenzodioxoles.
- Newton, Josiah J.,Brooke, Alan J.,Duhamel, Bastian,Pulfer, Jason M.,Britton, Robert,Friesen, Chadron M.
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p. 13298 - 13305
(2020/11/26)
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- Method for simultaneously preparing 2-ethoxyphenol and 1,3-benzodioxolane-2-one
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The invention belongs to the field of organic synthesis, and provides a method for simultaneously preparing 2-ethoxyphenol and 1,3-benzodioxolane-2-one. According to the preparation method, catechol and diethyl carbonate are subjected to transesterification under the action of a catalyst, so that the 2-ethoxyphenol and the 1,3-benzodioxolane-2-one can be obtained. The combined selectivity of the 2-ethoxyphenol and the 1,3-benzodioxolane-2-one can reach 97%, and the method has the advantages of high conversion rate, high selectivity, high economic benefit, environmental friendliness and the like.
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Paragraph 0024-0027
(2020/06/09)
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- CARBONATE DERIVATIVE PRODUCTION METHOD
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The objective of the present invention is to provide a method for producing a carbonate derivative in a safe and efficient manner. The method for producing a carbonate derivative according to the present invention is characterized in comprising irradiating light on a composition containing a C1-4 halogenated hydrocarbon having one or more kinds of halogen atoms selected from the group consisting of a chlorine atom, a bromine atom and an iodine atom, a nucleophilic functional group-containing compound and the specific base in the presence of oxygen.
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Paragraph 0114-0115
(2020/04/09)
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- Diphenyl Carbonate: A Highly Reactive and Green Carbonyl Source for the Synthesis of Cyclic Carbonates
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A practical, safe, and highly efficient carbonylation system involving a diphenyl carbonate, an organocatalyst, and various diols is presented herein and produces highly valuable cyclic carbonates. In reactions with a wide range of diols, diphenyl carbonate was activated by bicyclic guanidine 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as a catalyst, which successfully replaced highly toxic and unstable phosgene or its derivatives while maintaining the desired high reactivity. Moreover, this new system can be used to synthesize sterically demanding cyclic carbonates such as tetrasubstituted pinacol carbonates, which are not accessible via other conventional methods.
- Baral, Ek Raj,Lee, Jun Hee,Kim, Jeung Gon
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p. 11768 - 11776
(2018/09/27)
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- The design of efficient carbonate interchange reactions with catechol carbonate
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Catechol carbonate (CC) has been investigated as an innovative and highly active reactant for carbonate interchange reactions (CIRs). Under mild conditions (atmospheric pressure, and 60-80°C), the selective synthesis of symmetric aliphatic carbonates (ROCO2R) has been achieved by the reaction of a slight excess of both primary and secondary alcohols with CC in the presence of NaOMe or MgO as a catalyst. Quantitative conversions have been reached in only 1 hour and products have been isolated in yields of up to 58% for dibutylcarbonate. Of note is that the reaction of glycerol with CC also proceeded under similar conditions (40-60°C, 1 atm) to afford glycerol carbonate (96-98%). The comparison of the reactivity of CC with that of conventional dialkyl carbonates, including dimethyl carbonate (DMC) and ethylene carbonate (EC), proved the superior performance of CC in all the investigated CIR processes. Accordingly, a mechanism has been formulated based on the leaving group ability of a catecholate anion originating from CC.
- Tabanelli,Monti,Cavani,Selva
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supporting information
p. 1519 - 1528
(2017/05/01)
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- Continuous Flow Synthesis of Carbonylated Heterocycles via Pd-Catalyzed Oxidative Carbonylation Using CO and O2 at Elevated Temperatures and Pressures
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A continuous-flow Pd-catalyzed oxidative carbonylation protocol utilizing CO and O2 gas for the synthesis of carbonylated heterocycles is described. The optimization of temperature, pressure, CO/O2 ratio, catalyst loading, and reaction time resulted in process intensified conditions for this transformation. The optimized continuous flow conditions (120 °C, 20 bar pressure, 24 min residence time) were used to prepare a number of benzoxazolone, 2-benzoxazolidinone, and other biologically and synthetically important five- and six-membered carbonylated heterocycles in good overall yield and purity (14 examples). The continuous-flow process enables the safe and scalable oxidative carbonylation using CO/O2 under elevated pressures and temperatures.
- Chen, Yuesu,Hone, Christopher A.,Gutmann, Bernhard,Kappe, C. Oliver
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p. 1080 - 1087
(2017/07/26)
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- Lanthanide-catalyzed cyclocarbonylation and cyclothiocarbonylation: A facile synthesis of benzannulated 1,3-diheteroatom five- and six-membered heterocycles
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La[N(SiMe3)2]3 proves to be an efficient catalyst system for the cyclocarbonylation of 1,2-disubstituted benzenes with isocyanates. In this approach, aryl/alkyl isocyanates react with o-phenylenediamine, o-aminophenol, o-aminothiophenol, catechols and anilines ortho-substituted by CH2NH2 and CONH2 to form, respectively, the corresponding benzimidazolones, benzoxazolones, benzothiazolones, benzodioxolones, 3,4-dihydroquinazolin-2(1H)-one, and quinazolinediones. These results represent the first example of lanthanide-catalyzed carbonylation. This methodology is also applicable for the preparation of various benzannulated 1,3-diheteroatom cyclic thioketones starting from aryl/alkyl isothiocyanates or CS2 in good to excellent yields. Based on the results of experiments performed using an o-aminobenzamido dianion lanthanide complex, a general mechanism, involving the tandem reaction of two lanthanide-ligand bonds with one heterocumulene molecule, is proposed as well.
- Jing, Yufeng,Liu, Ruiting,Lin, Yanghui,Zhou, Xigeng
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p. 1117 - 1125
(2014/08/18)
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- Synthesis and biological evaluation of phenstatin metabolites
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Previous investigations on the incubation of phenstatin with rat and human microsomal fractions revealed the formation of nine main metabolites. The structures of eight of these metabolites have been now confirmed by synthesis and their biological properties have been reported. Eaton's reagent was utilized as a convenient condensing agent, allowing, among others, a simple multigram scale preparation of phenstatin. Synthesized metabolites and related compounds were evaluated for their antiproliferative activity in the NCI-60 cancer cell line panel, and for their effect on microtubule assembly. Metabolite 23 (2′-methoxyphenstatin) exhibited the most potent in vitro cytotoxic activity: inhibition of the growth of K-562, NCI-H322M, NCI-H522, KM12, M14, MDA-MB-435, NCI/ADR-RES, and HS 578T cell lines with GI50 values 50 = 3.2 μM vs 15.0 μM) and induced G2/M arrest in murine leukemia DA1-3b cells. The identification of this active metabolite led to the design and synthesis of analogs with potent in vitro cytotoxicity and inhibition of microtubule assembly.
- Ghinet, Alina,Rigo, Beno?t,Hénichart, Jean-Pierre,Le Broc-Ryckewaert, Delphine,Pommery, Jean,Pommery, Nicole,Thuru, Xavier,Quesnel, Bruno,Gautret, Philippe
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p. 6042 - 6054
(2011/11/29)
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- Synthesis of benzo-fused five- and six-membered heterocycles by palladium-catalyzed cyclocarbonylation
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A novel and simple synthetic methodology, based on palladium-catalyzed cyclocarbonylation reaction, is presented for preparing five- and six-membered benzo-fused heterocycles. A mechanism for the process is also proposed and discussed.
- Troisi, Luigino,Granito, Catia,Perrone, Serena,Rosato, Francesca
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experimental part
p. 4330 - 4332
(2011/09/13)
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- Method for Making Carbonates and Esters
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A method for forming a monomeric carbonate includes the step of combining a monofunctional alcohol or a difunctional diol with an ester-substituted diaryl carbonate to form a reaction mixture. Similarly, a method for forming a monomeric ester includes the step of combining a monofunctional carboxylic acid or ester with an ester-substituted diaryl carbonate to form a reaction mixture. These methods further include the step of allowing the reaction mixtures to react to form a monomeric carbonate or a monomeric ester, respectively.
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Page/Page column 8
(2010/06/13)
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- Selective production of methoxyphenols from dihydroxybenzenes on alkali metal ion-loaded MgO
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Selective O-methylation of dihydroxybenzenes (DHBs; catechol, resorcinol, and hydroquinone) to methoxyphenols (MPs) was carried out with dimethylcarbonate on MgO and alkali metal ion (Li, K, and Cs)-loaded MgO between 523 and 603 K. Catalytic activity and product selectivity varied with respect to DHB substrates. Selectivity for O-methylated products increased with increasing basicity of alkali ions; however, K-MgO showed high and stable activity toward MPs. Selectivity for MPs obtained from three substrates increased in the following order: catechol 2 followed by air and 13C CP-MAS NMR measurements indicated the nature of deposited carbon to be molecular species, graphite, MgCO3 and polyaromatics. XPS revealed the nature and availability of active sites on the spent catalysts, as well as the same changes with reaction conditions and correlated with catalytic activity.
- Vijayaraj, Munusamy,Gopinath, Chinnakonda S.
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p. 376 - 388
(2007/10/03)
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- Iminium Salts in Quantitative Gas/Solid and Solid/Solid Reactions
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Iminium salts that are highly susceptible to hydrolysis are quantitatively prepared and reacted in the solid state without solvents or liquid phases. Atomic force microscopy AFM helps in elucidating the mechanism of these still unusual gas-solid and solid-solid syntheses by recording surface topographies of reacting crystals of L-histidine (10) and triphenylverdazyl (15). Various imines add gaseous HCl or HBr to form stable iminium halides (1, 3, 4, 5, 11) even if frozen liquids of very weak heterocyclic bases are treated at low temperatures. Another way for quantitative yields of iminium salt hydrates (6) starts with solid primary ammonium halides and gaseous acetone. o-Phenylenediamines (7) give quantitatively 1,5-benzodiazepines (9) by solid state cyclization of bis-iminium salt intermediates (8). Crystalline nitroxyls (12) and triphenylverdazyl (15) undergo stoichiometric one-electron transfer with gaseous NO2 or XeF2 to give nitrosonium (14) and azonium salts (17). The solid state chlorination of tetramethylthiuramdisulfide (18) or dimethylthiocarbamoylchloride (20) yields phosgene dimethyliminiumchloride (Viehe salt 21) in quantitative yield. Solid Viehe salt is quantitatively treated with gaseous Cl2 to give the trichloride 19 and solid SbCl5 or PCl5 to produce the hexachloroantimoniates (22), -phosphates (23). Solid brenzcatechol (24), mercaptobenzimidazole (27), p-nitroaniline (30), N-methylbenzothiazolone-2-hydrazone (34) and acetophenone (41) are treated with 21 to give the corresponding chloroiminium salts (25, 28, 31, 35, 43). p-Toluenesulfonamide (37) and 22 give the chloroiminium salt 38.These quantitative solid-solid reactions are most easily run in ball mills with cooling device. The "waste-free" techniques achieve exclusion of moisture in an elegant way. The preparative use of the versatile products with nucleophiles is indicated. The three-step solid-state mechanisms are discussed.
- Kaupp, Gerd,Boy, Juergen,Schmeyers, Jens
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p. 346 - 355
(2007/10/03)
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- Liquid-Phase Decarboxylation of Aromatic Haloformates: A New Access to Chloro- and Fluoroaromatics
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The treatment of phenyl chloroformates 1 with a Lewis acid in the liquid phase resulted in decarboxylation to the corresponding chloroaromatics 2. Fluoroaromatic compounds were synthesized from phenylchloroformates 1 through a sequential fluorination/decarboxylation in the liquid phase by treatment with excess anhydrous hydrogen fluoride under mild conditions. In all cases, yields were increased by performing the reaction in 1,2,4-trichlorobenzene, which is inert to Friedel-Crafts reactions.
- Lui, Norbert,Marhold, Albrecht,Rock, Michael H.
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p. 2493 - 2496
(2007/10/03)
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- Electrophilic Carboxylation of Alkenes
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In the presence of 1.2 equivalents of boron trichloride 2,2-dichloro-1,3-benzodioxol (2) reacts with alkenes 4 to form 1:1 addition products 6, which are converted into the unsaturated tert-butyl esters 7 on treatment with potassium tert-butoxide.In the presence of ZnCl2, these reactions do not usually terminate at the 1:1 product stage, and 2,2-disubstituted 1,3-benzodioxols 5 are formed by reaction of 2 with two equivalents of 4a-f.
- Mayr, Herbert,Brueggen, Uwe von der
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p. 339 - 346
(2007/10/02)
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