1125-88-8Relevant articles and documents
Hydrothermal synthesis of chiral inorganic-organic CoII complex: Structural, thermal and catalytic evaluation
Salah, Assila Maatar Ben,Herrera, Raquel P.,Na?li, Houcine
, p. 356 - 362 (2018)
By heating the cobalt chloride hexahydrate (CoCl2·6H2O) with the R form of the organic amine α-methylbenzylamine (C8H11N) under hydro(solvo)thermal conditions, we have successfully generated the corresponding non-centrosymmetric homochiral hybrid tris (α-methylbenzylammonium tetrachloridocobaltate chloride [R-(C8H12N)3][CoCl4]Cl abbreviated R(MBA)Co. We present the growth conditions together with a characterization of the single crystals by means of X-ray single-crystal diffraction, Fourier-transform infrared, TG/TDA thermal decomposition and catalytic properties. This inorganic–organic hybrid compound crystallizes in the chiral space group P21 and exhibits a supramolecular-layered organization wherein a double layer of (R)-methylbenzylammonium cations and the uncoordinated chloride anions are sandwiched between anionic layers, formed by isolated tetrachloridocobaltate tetrahedra. The crystal packing is governed by a three-dimensional network of N/C–H?Cl hydrogen bonds between the inorganic and organic moieties and C–H···π interactions between the aromatic rings of the organic moieties themselves. Thermal analysis discloses a phase transition at the temperature 130 °C. The Co complex was also employed as suitable catalyst activating the acetal formation reaction of aldehydes using MeOH as solvent and as the unique source of acetalization.
Ru(II)-functionalized SBA-15 as highly chemoselective, acid free and sustainable heterogeneous catalyst for acetalization of aldehydes and ketones
Lazar, Anish,Betsy,Vinod,Singh
, p. 62 - 66 (2018)
Combining electron deficient Ru(II) coordination sites with organofunctionalized SBA-15, (L)Ru(II)@SBA-15, result in a mild, neutral, water scavenger free and chemo-selective acetalization catalyst for cyclic/acyclic acetals. Vacant coordination sites of ruthenium in (L)Ru(II)@SBA-15 activates protecting groups as well as reactants simultaneously and restricts the reverse acetalization reaction. Synthesized (L)Ru(II)@SBA-15 catalyst has been thoroughly characterized and act as competitive catalyst compared to conventional acid catalysts. (L)Ru(II)@SBA-15 performs high catalytic activity as well as selectivity within 20 min with high TOF. The catalyst can be recycled and reaction parameters are optimized.
Direct Asymmetric Friedel-Crafts Reaction of Naphthols with Acetals Catalyzed by Chiral Bronsted Acids
Qin, Long,Wang, Pei,Zhang, Yixin,Ren, Zhengxiang,Zhang, Xin,Da, Chao-Shan
, p. 571 - 574 (2016)
The Friedel-Crafts method synthesis of chiral ethers from various acetals and naphthols catalyzed by chiral Bronsted acids with acetic acid as an effective additive is described. We found that the chiral phosphoric acid (R)-TRIP could efficiently catalyze the asymmetric Friedel-Crafts reaction of naphthols with acetals affording chiral ethers in good enantioselectivity and yield.
Crystallisation, thermal analysis and acetal protection activity of new layered Zn(II) hybrid polymorphs
Sa?d, Salem,Na?li, Houcine,Bataille, Thierry,Herrera, Raquel P.
, p. 5365 - 5374 (2016)
Two new polymorphic mononuclear complexes, with analogous structural formula (C6H9N2)2[Zn(H2O)6](SO4)2·2H2O, of zinc(ii) templated by 2-amino-6-methylpyridinium ligand have been discovered. These polymorphic hybrid crystals, which differ only in terms of their crystal structures, were prepared in one-step synthesis under ambient conditions and investigated for their thermal and catalytic properties. Single-crystal X-ray diffraction of the obtained materials revealed that polymorphs 1 and 2 crystallise in the triclinic system, space group P1. In an effort to further explore the form diversity of these compounds, the structural arrangements and intermolecular interactions such as hydrogen-bonding and π?π interactions are discussed from which supramolecular assembly was formed. Meanwhile, these new polymorphic forms can be described as the stacking of 3D layers where the interlayer distances are 13.23 and 12.59 ? for 1 and 2, respectively. The thermal behaviour of the precursors checked by TG-DTA analysis for both zinc sulfate polymorphs and variable temperature powder X-ray diffraction (VT-PXRD) show successive intermediate crystalline anhydrous phases upon dehydration in 1. The catalytic activity of both polymorphic structures has been tested in the acetalisation reaction of aldehydes as a benchmark process. Interestingly, both complexes showed excellent activity with almost total conversion in many examples and using MeOH as solvent and as the unique source of acetalisation.
MOF-808 as a recyclable catalyst for the photothermal acetalization of aromatic aldehydes
Rabon, Allison M.,Doremus, Jared G.,Young, Michael C.
, (2021)
Metal-organic frameworks (MOFs) show promise for catalysis applications due to their porosity, high internal surface area, and structural adaptability. Typical acetylation reactions of aldehydes require elevated temperatures and excess alcohol to drive the reactions to completion. In this current work, MOF-808 is used as a heterogeneous catalyst for acetylation of aldehydes in methanol using a mild photothermal process. Optimized conditions gave 72% yield of 2-(dimethoxymethyl)naphthalene in the presence of 10 mol% MOF-808 at 45 °C using only a fluorescent lamp. MOF-808 can be recycled up to 5 times with no loss in catalytic activity. A proof-of-principle substrate scope demonstrates the potential utility for aromatic and aliphatic substrates.
Davis et al.
, p. 2349 (1976)
Modification of Au nanoparticles electronic state by MOFs defect engineering to realize highly active photocatalytic oxidative esterification of benzyl alcohol with methanol
Fan, Chaoyang,Wang, Ruiyi,Kong, Peng,Wang, Xiaoyu,Wang, Jie,Zhang, Xiaochao,Zheng, Zhanfeng
, (2020)
Defect modified UiO-66 supported Au nanoparticles exhibited excellent catalytic performance in the oxidative esterification of benzyl alcohol with methanol under mild conditions. The defects were generated by introducing HCl during the preparation procedure. The defects exposed the Lewis acid of coordinatively unsaturated metal sites, which is benefit for Au loading and changing Au nanoparticles (NPs) to a negative electron state. The negatively charged Au nanoparticle promoted the reaction by strong oxygen activation ability. The present study could help to unravel the synergistic effect of support and metal interaction and provides an efficient photocatalytic route for synthesis high-value esters in terms of sustainable chemistry.
Electrochemical methoxylation of styrene with gas-lift in continuous mode
Il'chibaeva,Kagan,Tomilov
, p. 1318 - 1320 (2001)
Anodic oxidation of styrene in methanol was performed in an electrolyzer with gas-lift. The possibility of carrying this process out in continuous mode with the use of technical-grade methanol was studied.
New reaction of di- and trichloromethylbenzenes with orthoformic esters [6]
Gazizov,Gazizov,Karimova,Pudovik,Nikitin,Sinyashin
, p. 1465 - 1466 (2004)
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Series of 2D heterometallic coordination polymers based on ruthenium(III) oxalate building units: Synthesis, structure, and catalytic and magnetic properties
Dikhtiarenko, Alla,Khainakov, Sergei A.,De Pedro, Imanol,Blanco, Jesus A.,Garcia, Jose R.,Gimeno, Jose
, p. 3933 - 3941 (2013)
A series of 2D ruthenium-based coordination polymers with hcb-hexagonal topology, {[K(18-crown-6)]3[MII3(H 2O)4{Ru(ox)3}3]}n (M II = Mn (1), Fe (2), Co (3), Cu (4), Zn (5)), has been synthesized through self-assembly reaction. All compounds are isostructural frameworks that crystallize in the monoclinic space group C2/c. The crystal packing consists of a 2D honeycomb-like anionic mixed-metal framework intercalated by [K(18-crown-6)]+ cationic template. Dehydration processes take place in the range 40-200 C exhibiting two phase transitions. However, the spontaneous rehydration occurs at room temperature. Both hydrated and dehydrated compounds were tested as Lewis acids heterogeneous catalysts in the acetalyzation of benzaldehyde achieving high yields with the possibility to be recovered and reused. All the investigated materials do not show any long-range magnetic ordering down to 2 K. However, the Fe-based compound 2 presents a magnetic irreversibility in the ZFC-FC magnetization data below 5 K, which suggest a spin-glass-like behavior, characterized also by short-range ferromagnetic correlations. The coercive field increases as the temperature is lowered below 5 K, reaching a value of 1 kOe at 2 K. Alternating current measurements obtained at different frequencies confirm the freezing process that shows weak frequency dependence, being characteristic of a system exhibiting competing magnetic interactions.
Cobalt(II) schiff base functionalized mesoporous silica as an efficient and recyclable chemoselective acetalization catalyst
Rajabi
, p. 695 - 701 (2010)
Cobalt(II) Schiff base functionalized mesoporous silica was synthesized from covalent attachment via the introduction of Co(OAc)2 to salicylaldimine functionalized mesoporous silica. The catalyst proved to be chemoselective one for the acetalization of aldehydes to the corresponding acetals in alcohol. The immobilized catalyst can be easily recovered and reused for at least ten reaction cycles without significant loss of its catalytic activity.
A new molecular iodine-catalyzed acetalization of carbonyl compounds
Basu, Manas K.,Samajdar, Susanta,Becker, Frederick F.,Banik, Bimal K.
, p. 319 - 321 (2002)
A new and facile molecular iodine-catalyzed acetalization of carbonyl compounds has been developed. Useful selectivity has also been demonstrated.
Influence of Terephthalic Acid Substituents on the Catalytic Activity of MIL-101(Cr) in Three Lewis Acid Catalyzed Reactions
Santiago-Portillo, Andrea,Navalón, Sergio,Concepción, Patricia,álvaro, Mercedes,García, Hermenegildo
, p. 2506 - 2511 (2017)
Six isostructural MIL-101(Cr)-X (X: H, NO2, SO3H, Cl, CH3, and NH2) materials have been prepared directly by the reaction of CrIII salts and the corresponding terephthalic acid or by postsynthetic treatments of preformed MIL-101(Cr) following reported procedures. The materials were characterized by using XRD (crystallinity and coincident diffraction pattern), isothermal N2 adsorption (specific surface areas range from 2740 m2 g?1 for MIL-101(Cr)-H to 1250 m2 g?1 for MIL-101(Cr)-Cl), thermogravimetry (thermal stability up to 400 °C), and IR spectroscopy (detection of the corresponding substituents), and the results were all in agreement with the reported data for these materials. The MIL-101(Cr) materials were tested as heterogeneous catalysts for epoxide ring opening by methanol, benzaldehyde acetalization by methanol, and Prins coupling, observing a clear influence of the substituent that in general follows a linear relationship with the Hammett σmeta constant of the substituent: the catalytic activity increases as the electron-withdrawing ability of the substituents increases. An up to three orders of magnitude enhancement in the presence of the NO2 substituent was found for some of these reactions. The present study illustrates the versatility that metal–organic frameworks offer as heterogeneous catalysts that allow the design of actives sites with adequate properties tuned for each reaction.
Guest molecule release triggers changes in the catalytic and magnetic properties of a FeII-based 3D metal-organic framework
Xu, Zhouqing,Meng, Wei,Li, Huijun,Hou, Hongwei,Fan, Yaoting
, p. 3260 - 3262 (2014)
A FeII-based metal-organic framework (MOF), {[Fe 2(pbt)2(H2O)2]·2H 2O}n, undergoes an irreversible dehydration, which triggers changes in the catalytic and magnetic properties of the MOF. These property changes are attributed to the high-spin to low-spin transition of 7.1% center FeII, which is demonstrated by 57Fe Moessbauer, X-ray photoelectron spectroscopy, and UV/vis absorption spectra.
Hierarchical porous organic polymer as an efficient metal-free catalyst for acetalization of carbonyl compounds with alcohols
Kim, Joong-Jo,Lim, Cheang-Rae,Reddy, Benjaram M.,Park, Sang-Eon
, p. 43 - 50 (2018)
An efficient melamine-porous organic polymer (M-POP) as N-functionalized organic polymer catalyst was synthesized with melamine and terephthalaldehyde by a facile microwave-assisted method. The synthesized M-POP exhibited a high specific surface area with hierarchical pore structure of both mesoporosity and microporosity. The rich N-moieties namely, C[dbnd]N and N–H from the melamine precursor were found to show hydrogen-bonding ability with various organic molecules such as carbonyl compounds. This was illustrated in the acetalization of aldehydes and ketones with methanol or ethylene glycol under mild conditions as a metal-free H-bonding catalyst with high product selectivity. The superior catalytic performance of M-POP was attributed to the availability of a large number of H-bonding sites both as H-donor and H-acceptor between the reactants and the catalyst.
A novel, mesoporous molybdenum doped titanium dioxide/reduced graphene oxide composite as a green, highly efficient solid acid catalyst for acetalization
He, Junkai,Kankanam Kapuge, Tharindu,Kerns, Peter,Meguerdichian, Andrew G.,Suib, Steven L.,Thalgaspitiya, Wimalika R. K.
, p. 3786 - 3795 (2020)
A novel, mesoporous composite of Mo doped TiO2/reduced graphene oxide is synthesized to be used as a highly efficient heterogeneous acid catalyst. The composite has a high surface area (263 m2 g-1) and a monomodal pore size distribution with an average pore diameter of 3.4 nm. A comprehensive characterization of the synthesized material was done using PXRD, Raman, BET, SEM, EDX, TEM, TGA, and XPS. The composite exhibited excellent catalytic activity (1.6 h-1 TOF, >99% GC yield, and >99% selectivity) towards acetalization of cyclohexanone at room tempertaure within 30 minutes. The catalyst was reusable up to 4 reaction cycles without any significant loss in the activity and the acidic site calculations showed that the reaction is mostly driven by the weak acidic sites on the composite.
The use of anhydrous CeCl3 as a recyclable and selective catalyst for the acetalization of aldehydes and ketones
Silveira, Claudio C.,Mendes, Samuel R.,Ziembowicz, Francieli I.,Lenarda?o, Eder J.,Perin, Gelson
, p. 371 - 374 (2010)
An efficient, clean, chemoselective and solvent-free method for the synthesis of ketone and aldehyde dimethyl acetals was developed using trimethyl orthoformate and commercially available anhydrous CeCl3 as a recyclable catalyst. The method is general and affords the protected carbonyl compounds in good yields and under mild conditions, including aryl and alkyl ketones and activated aldehydes. The catalyst could be utilised directly for 3 cycles, without significant loss of activity.
Robust Multifunctional Yttrium-Based Metal-Organic Frameworks with Breathing Effect
Firmino, Ana D. G.,Mendes, Ricardo F.,Antunes, Margarida M.,Barbosa, Paula C.,Vilela, Sérgio M. F.,Valente, Anabela A.,Figueiredo, Filipe M. L.,Tomé, Jo?o P. C.,Paz, Filipe A. Almeida
, p. 1193 - 1208 (2017)
Phosphonate- and yttrium-based metal-organic frameworks (MOFs), formulated as [Y(H5btp)]·5.5H2O (1), [Y(H5btp)]·2.5H2O (2), (H3O)[Y2(H5btp)(H4btp)]·H2O (3), and [Y(H5btp)]·H2O·0.5(MeOH) (4), were prepared using a “green” microwave-assisted synthesis methodology which promoted the self-assembly of the tetraphosphonic organic linker [1,1′-biphenyl]-3,3′,5,5′-tetrayltetrakis(phosphonic acid) (H8btp) with Y3+ cations. This new family of functional materials, isolated in bulk quantities, exhibits a remarkable breathing effect. Structural flexibility was thoroughly studied by means of X-ray crystallography, thermogravimetry, variable-temperature X-ray diffraction, and dehydration and rehydration processes, ultimately evidencing a remarkable reversible single-crystal to single-crystal (SC-SC) transformation solely through the loss and gain of crystallization solvent molecules. Topologically, frameworks remained unaltered throughout this interconversion mechanism, with all compounds being binodal 6,6-connected network with a Scha?fli symbol of {413.62}{48.66.8}. Results show that this is one of the most stable and thermally robust families of tetraphosphonate-based MOFs synthesized reported to date. Porous materials 2 and 3 were further studied to ascertain their performance as heterogeneous catalysts and proton conductors, respectively, with outstanding results being registered for both materials. Compound 2 showed a 94% conversion of benzaldehyde into (dimethoxymethyl)benzene after just 1 h of reaction, among the best results registered to date for MOF materials. On the other hand, the protonic conductivity of compound 3 at 98% of relative humidity (2.58 × 10-2 S cm-1) was among the highest registered among MOFs, with the great advantage of the material to be prepared using a simpler and sustainable synthesis methodology, as well as exhibiting a good stability at ambient conditions (temperature and humidity) over time when compared to others.
Natural kaolinitic clay: A remarkable reusable solid catalyst for the selective functional protection of aldehydes and ketones
Ponde, Datta,Borate,Sudalai,Ravindranathan,Deshpande
, p. 4605 - 4608 (1996)
Natural kaolinitic clay possessing transition metals such as Fe and Ti in its lattice has been found to catalyze efficiently the chemoselective acetalization and thioacetalization of variety of carbonyl compounds with ethane - 1,2 - diol and ethane - 1,2 - dithiol respectively.
[Hmim]3PW12O40: A high-efficient and green catalyst for the acetalization of carbonyl compounds
Dai, Yan,Li, Bin Dong,Quan, Heng Dao,Lü, Chun Xu
, p. 678 - 681 (2010)
[Hmim]3PW12O40 was developed and used in the acetalization of carbonyl compounds in excellent yields. The ionic liquid-heteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separation system with the ease of product as well as catalyst separation. The catalyst was recycled more than 10 times without any apparent loss of catalytic activity.
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Kollonitsch,Vita
, p. 1307 (1956)
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Direct aerobic photo-oxidative syntheses of aromatic methyl esters from methyl aromatics using anthraquinone-2,3-dicarboxylic acid as organophotocatalyst
Tada, Norihiro,Ikebata, Yuki,Nobuta, Tomoya,Hirashima, Shin-Ichi,Miura, Tsuyoshi,Itoh, Akichika
, p. 616 - 619 (2012)
This paper reports a useful method for facile direct syntheses of aromatic methyl esters from methyl aromatics by aerobic photo-oxidation using anthraquinone-2,3-dicarboxylic acid as an organophotocatalyst.
ELECTROCHEMICAL OXIDATION OF 1-ALKENYLARENES TO GIVE BENZALDEHYDE DIMETHYL ACETALS
Ogibin, Yu. N.,Elinson, M. N.,Sokolov, A. V.,Nikishin, G. I.
, p. 432 (1990)
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Fabrication of novel hybrid nanoflowers from boron nitride nanosheets and metal-organic frameworks: A solid acid catalyst with enhanced catalytic performance
Wang, Peng,Li, Hao,Gao, Qiang,Li, Pei-Zhou,Yao, Xin,Bai, Linyi,Nguyen, Kim Truc,Zou, Ru-Qiang,Zhao, Yanli
, p. 18731 - 18735 (2014)
A double solvent replacement method was employed for the synthesis of novel hybrid nanoflowers from boron nitride nanosheets (BNNSs) and the metal-organic framework (MOF) MIL-53 in aqueous solutions under hydrothermal treatments. The strong binding abilit
Evans
, p. 473 (1972)
Supported Iridium Catalyst for Clean Transfer Hydrogenation of Aldehydes and Ketones using Methanol as Hydrogen Source
He, Guangke,Liu, Xiang,Wang, Jing,Ye, Sen,Zhu, Jiazheng,Zhu, Longfei
, (2022/02/01)
The use of methanol as abundant and low-toxic hydrogen source under mild and clean conditions is promising for the development of safe and sustainable reduction processes, but remains a daunting challenge. This work presents a recyclable ZnO-supported Ir
Highly efficient and selectivity-controllable aerobic oxidative cleavage of C-C bond over heterogeneous Fe-based catalysts
Guo, Pengfei,Liao, Shengyun,Wang, Shun,Shi, Jing,Tong, Xinli
, p. 399 - 403 (2021/02/27)
A base-free selectivity-controllable aerobic oxidative cleavage of C-C bond with heterogeneous Fe-based catalysts (FexOy-N@C3N4) is developed. In the presence of oxygen, 1,2-diols are selectively transformed to the corresponding aldehyde, while the methyl esters are orientedly produced from 1,2-diones in methanol medium.