177-10-6Relevant articles and documents
Three molybdophosphates based on Strandberg-type anions and Zn(ii)-H 2biim/H2O subunits: Syntheses, structures and catalytic properties
Li, Zi-Liang,Wang, Ying,Zhang, Lan-Cui,Wang, Jian-Ping,You, Wan-Sheng,Zhu, Zai-Ming
, p. 5840 - 5846 (2014)
Three new inorganic-organic hybrid compounds based on Strandberg-type anions and Zn(ii)-H2biim/H2O subunits, namely {H 4(H2biim)3}[Zn(H2biim)(H 3biim)(H2O)(HP2Mo5O 23)]2·3H2O (1), {H9(H 2biim)7}[(μ-biim){(Zn(H2O)2) 0.5(HP2Mo5O23)}2] ·7H2O (2) and {H7(H2biim) 7}[Zn(H2biim)(H2O)2(HP 2Mo5O23)][H2P2Mo 5O23]·8H2O (3) (H2biim = 2,2′-biimidazole), have been synthesized in aqueous solutions and characterized. They were also used as efficient and reusable catalysts for the protection of carbonyl compounds. Their fascinating structural features are that mono Zn(ii)-supporting biphosphopentamolybdate ({P2Mo5}) clusters exist in their crystal structures, and the nitrogen donor ligand H 2biim exhibits three different coordination modes in these three compounds, respectively: for 1, two 2,2′-biimidazole molecules, as mono- and bidentate ligands coordinate to the same Zn(ii) ion; for 2, one bi-negative tetradentate ligand μ-biim bridges two Zn(ii) ions, while for 3, one neutral bidentate H2biim ligand links one Zn(ii) ion. Most importantly, compounds 1-3 represent the first example where Strandberg-type POMs are used as acid-catalysts in an organic reaction.
Four Strandberg-type polyoxometalates with organophosphine centre decorated by transition metal-2,2'-bipy/H2O complexes
Lu, Ting,Feng, Shu-Li,Zhu, Zai-Ming,Sang, Xiao-Jing,Su, Fang,Zhang, Lan-Cui
, p. 52 - 57 (2017)
Four inorganic-organic hybrid compounds composed of Strandberg-type organophosphomolybdate anion [(C6H5PO3)2Mo5O15]4? (abbreviated as (PhP)2Mo5) and transition metal (TM)?2,2'-bipy/H2O complex units, namely [(TM(H2O)(bipy))2(C6H5PO3)2Mo5O15]n (TM = Co, (1); Ni, (2)), [(Cu(bipy)2)2(C6H5PO3)2Mo5O15]?2H2O (3) and [(Zn(bipy)(μ-OH))2(Zn(bipy)2(C6H5PO3)2Mo5O15)2]?3H2O (4) (bipy = 2,2'-bipyridine), were successfully constructed under hydrothermal conditions, and their structures were determined by single crystal X-ray diffraction analysis and spectroscopic methods. The central heteroatoms in these polyoxometalates (POMs) are all organophosphine (RP) groups. Compound 1 and compound 2 are isostructural (PhP)2Mo5-based TM-coordination polymers with the two-dimensional layer frameworks. In compound 3, the bi-supporting structure containing one (PhP)2Mo5 unit and two [Cu(bipy)2]2+ cations. For compound 4, it can be regarded as a dimer of two bi-supporting {Zn(bipy)2(PhP)2Mo5Zn(bipy)} clusters that were connected by two μ-OH groups. The acid-catalytic activities and fluorescence properties of the four hybrids have been investigated.
Acetalization and Transacetalization Reactions Catalyzed by Ruthenium, Rhodium, and Iridium Complexes with {2-{{Bis[3-(trifluoromethyl)phenyl]phosphino}methyl}-2-methylpropane-1,3-diyl}bis[bis[3-(trifluoromethyl)phenyl]phosphine] (MeC[CH2P(m-CF3C6H4)2]3)
Suelue, Mustafa,Venanzi, Luigi M.
, p. 898 - 907 (2001)
The complexes [RhCl(3-n)(MeCN)n(CF3triphos)](CF3SO3)n (n = 1, 2; CF3triphos = MeC[CH2P(m-CF3C6H4)2]3) and [M(MeCN)3 (CF3triphos)](CF3SO3)n (M = Ru, n = 2; M = Ir, n = 3) are catalyst precursors for some typical acetalization and transacetalization reactions. The activity of these complexes is higher than those of the corresponding species containing the parent ligand MeC[CH2P(C6H5)2]3(Htriphos). Also the complexes [MCl3(tripod)] (tripod = Htriphos and CF3triphos) are active catalysts for the above reactions. The complex [RhCl2(MeCN)(CF3triphos)](CF3SO3) catalyzes the acetalization of benzophenone.
Preparation of hierarchically structured y zeolite with low Si/Al ratio and its applications in acetalization reactions
Jiao, Wen Qian,Fu, Wen Hua,Liang, Xiao Min,Wang, Yi Meng,He, Ming-Yuan
, p. 58596 - 58607 (2014)
Hierarchically structured Y zeolites were prepared by a post-synthetic strategy, where the as-made NaY zeolite was sequentially treated by a lactic acid solution and an alkaline solution containing cetyltrimethyl ammonium bromide (CTAB). Many techniques, including X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), N2 adsorption-desorption, Fourier-transform infrared spectroscopy (FT-IR), Thermogravimetric analysis (TG-DTG) and NH3 Temperature Programmed Desorption (NH3-TPD), were applied to characterize the chemical and textural properties of the samples. The results show that lactic acid pre-modification of NaY zeolite may cause on the one hand Na+ cation removal by proton exchange and on the other hand the dealumination of the zeolite framework with the formation of amorphous silicon-rich species offering nutrients for the fabrication of mesoporosity. After alkaline treatment in the presence of surfactant CTAB, mesoporosity can be successfully introduced into the NaHY zeolites with the microporous structures well preserved. Furthermore, the hierarchically structured Y zeolites exhibit much better performances in the acetalization reactions with large sized molecules involved. This could be attributed to the enhanced diffusion ability of large sized guest molecules through the combination of mesoporosity and microstructures compared with pure microporous Y zeolites.
On-fiber derivatization for determination of ethylene glycol concentration in lubricant oil by SPME-GC/MS
Lee, Joon-Bae,Shon, Shungkun,Kwon, O-Seong,Min, Ji Sook,Kim, Nam Yee,Paeng, Ki-Jung
, p. 938 - 941 (2016)
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Kinetic cyclohexylidenation and isopropylidenation of aldose diethyl dithioacetals
Grindley, T. Bruce,Cote, Christian J.P.,Wickramage, Chandra
, p. 215 - 238 (1985)
Aldose diethyl dithioacetals react with 1.2 equivalents of 1-ethoxycyclohexene or 2-methoxypropene in N,N-dimethylformamide at 0° with p-toluenesulfonic acid as catalyst to give the five-membered ring acetal attached to the two terminal oxygen atoms as the major product in every case. In most instances, a small proportion of the terminal, six-membered ring acetal was also obtained, and in a few cases, terminal seven-membered ring acetals were also isolated. Cyclohexylidenation at room temperature gave the same products, but isopropyl-idenation at room temperature resulted in certain cases in partial rearrangement. Cyclohexylidenation reactions gave smaller proportions of the minor six- and seven-membered ring products. Structures were established from13C-n.m.r. and mass spectra. The13C-n.m.r. spectra of model cyclohexylidene derivatives were found very similar to those of isopropylidene derivatives previously studied. Two new features useful for structure determination were noted when the spectra of the precursor diols were compared with those of both types of derived acetals; the chemical shift of C-2 of a 1,3-propanediol derivative was shifted upfield by 6-9 p.p.m. on acetalation and the shifts of the diol carbon atoms attached to oxygen were affected according to the type of acetal and ring-size formed. Similar observations were made for methylene acetals.
Indium triflate mediated tandem acetalisation-acetal exchange reactions under solvent-free conditions
Smith, Brendan M.,Graham, Andrew E.
, p. 6281 - 6283 (2011)
Acyclic acetals and ketals undergo exchange reactions in the presence of catalytic quantities of indium(III) triflate and diols to generate the corresponding cyclic acetals and ketals in excellent yield. The protocol is rapid, employs mild conditions and can be adapted to employ solvent-free reaction conditions. We have further developed this methodology to encompass a tandem acetalisation-acetal exchange protocol which provides facile access to cyclic ketals from unreactive ketones also under very mild, solvent-free reaction conditions.
An open chain carboxyethyltin functionalized sandwich-type tungstophosphate based on a trivacant Dawson subunit: Synthesis, characterization and properties
Bai, Jian-Ping,Su, Fang,Zhu, Hao-Tian,Sun, Hang,Zhang, Lan-Cui,Liu, Mei-Ying,You, Wan-Sheng,Zhu, Zai-Ming
, p. 6423 - 6430 (2015)
A Dawson sandwich-type polyoxometalate {C(NH2)3}12H4[αββα-{(Sn(C3H4O2))2Mn2(P2W15O56)2}]·22H2O (abbreviated as SnR-Mn-P2W15), functionalized by open chain carboxyethyltin groups, was first prepared in aqueous solution under conventional reaction conditions, and then structurally characterized by physicochemical and spectroscopic methods. Single crystal X-ray diffraction analysis revealed that two Mn2+ cations and two [Sn(CH2CH2COO)]2+ groups are located in the internal and external positions in the so-called equatorial region of SnR-Mn-P2W15, respectively. Intriguingly, two exposed carboxyl groups act as stretching-arm brackets, which provide a favorable structure for potential further functionalization. The electrocatalytic activity of SnR-Mn-P2W15 towards the reduction of hydrogen peroxide and nitrite was studied. Additionally, its acid catalysis and oxidation catalysis activities in organic synthesis were investigated. This journal is
Green efficient synthesis of ketal under catalysis of ionic liquid TTPT
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Paragraph 0034-0036, (2021/08/07)
The invention discloses a method for green efficient synthesis of ketal under catalysis of ionic liquid TTPT. The method comprises the following steps: adding TTPT and a water-carrying agent into a raw material I and a raw material II, and carrying out a heating reflux reaction for 110-150 minutes, wherein R1 and R2 in formulas I and II are independently selected from a group consisting of a methyl group, an ethyl group and a phenyl group, or R1 and R2 are connected and cyclized to form a 5-to-10-membered naphthenic base; and R3 is selected from H or-OH. Compared with the prior art, the catalytic yield of the TTPT is remarkably improved, a good catalytic effect is achieved, and experimental operation is easy and convenient.
Facile synthesis of acetal over a supported novel Br?nsted and lewis acid ionic liquid catalyst
Liu, Ruifeng,Dai, Liming,Zhao, Qian,Xie, Yingjie,Jiang, Tingshun
, p. 4396 - 4405 (2019/05/08)
A novel Br?nsted and Lewis acid ionic liquid (IL) chlorinated butyrolactam chlorozincinate (CPCl-ZnCl2) was synthesized by a hydrothermal process and characterized by Fourier transform infrared (FT-IR). The Fe-SBA-15 mesoporous materials with different Si/Fe mole ratios were prepared by direct synthesis method. The supported ionic liquid (IL/Fe-SBA-15) with various IL contents were prepared by a wet impregnation method and characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and N2 physical adsorption. The acidity was measured by FT-IR spectroscopy using pyridine as probes. The catalytic property was tested in acetalization of cyclohexanone with ethylene glycol. The results demonstrated that the IL/Fe-SBA-15 catalysts were of higher catalytic activity compared to Fe-SBA-15. Under optimal conditions, the acetalization could reach to 92.6% cyclohexanone conversion with 99.3% acetal selectivity. After 5 cycles, the cyclohexanone conversion decreased slightly. Also, the catalyst showed good catalytic property in the other acetalization of cyclohexanone and benzyl alcohol.
