Alkylation of dichlorobenzene isomers by olefins on zeolites Y and pentasil

Catalytic alkylation of dichlorobenzene isomers by ethylene and propylene on zeolite catalysts has been studied. It has been determined that using catalysts based on zeolite Y makes it possible to change the ratio of 1-alkyldichlorobenzenes formed within a wide range by varying the acidic properties of the catalysts.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1486–1488, August, 1995.     

在H型分子筛上萘与正己醇的烷基化反应

制备了H型分子筛HY,Hβ和HM,通过XRD,NH₃-TPD和Py-IR对其进行了表征,考察了其对萘与正己醇的烷基化反应的催化性质.结果表明,HY可作为己基化反应的催化剂,较高的反应温度和较长的反应时间对β-己基萘的生成有利.     

Alkylation of phenol with isopropanol over MCM-49 zeolites

Four novel Br?nsted acidic ionic liquids with two different acid sites on the imidazolium cations were synthesized and employed as catalysts and media in the esterification of acetonitrile with alcohols. The results showed that [HSO₃-pHim]HSO4 was the most efficient catalyst and medium which could be recycled easily without obvious decline in the catalytic activity.     

Pt改性分子筛催化剂上丙烷与苯的烷基化反应

研究了不同分子筛负载的Pt催化剂上丙烷与苯的烷基化反应.结果表明,Pt/HZSM-5具有较好的催化性能.在0~0.3%范围内提高Pt负载量可以提高催化剂的催化活性和生成C9以及C10 芳烃的选择性,降低非芳烃产物的选择性.较低的反应温度、较高的苯/丙烷摩尔比和较高的空速有利于烷基芳烃的生成.     

Efficient resolution of racemic 1,1'-bi-2-naphthol with chiral selectors identified from a small library

Efficient resolution of racemic 1,1'-bi-2-naphthol, a well-studied analyte in chiral separation, was achieved using selectors developed from a small library. Separation factors (up to 7.2) obtained are significantly higher than the ones reported previously for this analyte. The library consists of 121 members and it does not contain the pi deficient 3,5-dinitrobenzoyl (Dnb) group. These highly efficient stationary phases may lead to the practical large-scale chromatographic resolution of enantiomers of 1,1'-bi-2-naphthol, which are widely used as chiral auxiliaries and ligands in asymmetric synthesis.     

Mg-La-HY-SBA-15分子筛催化甲醇烷基化反应

用两步浸渍法制备了Mg-La-HY-SBA-15复合分子筛,在小型固定床反应器上考察了苯酚甲醇烷基化性能;通过SEM-EDS、Py-FTIR等表征手段分析了Mg-La-HY-SBA-15分子筛的孔结构和酸性。结果表明,Mg负载到HY-SBA-15分子筛上且未改变其微介孔结构; Mg改性后降低了载体的总酸量,增加了总Lewis酸,提高了邻甲酚的选择性和收率。     

改性HZSM-5催化剂上苯与乙醇烷基化反应的研究

采用离子交换方法,用硫酸铁、硝酸镍、硫酸钛对HZSM-5分子筛进行改性,得到三种不同金属改性的催化剂;通过XRD、ICP、BET、NH3-TPD、Py-IR对催化剂进行了表征,并在连续流动固定床反应装置上进行了活性评价。相同方法改性后钛的负载量最大,酸性变化不大;铁负载量次之,弱酸和中强酸量增加;镍的负载量最少,酸强度降低最多,孔径最小。反应评价结果表明,改性后的催化剂同未改性的相比苯的转化率增加,乙苯选择性略有降低,乙苯产率增加,其中铁、钛改性后的分子筛乙醇利用率增加。综合考虑,铁和钛是比较合适的改性元素。     

Separation of 2-naphthol atropisomers on cyclofructan-based chiral stationary phases

A set of fifteen 2-naphthol-derived atropisomers were evaluated on three different cyclofructan-based chiral stationary phases (CSP). The cyclofructan CSPs were a dimethylphenyl-derivatized cyclofructan 7 (CF7-DMP), a isopropyl (CF6-P) and a R-naphthylethyl cyclofructan 6 (CF6-RN) derivative, all bonded to 5-µm spherical fully porous silica particles packed into three 25?cm?×?4.6?mm columns (commercially available as Larihc columns). The 15 atropisomers were analyzed in the normal-phase mode with heptane/alcohol mobile phases. The CF7-DMP column was the most effective partially or fully separating 14 of the 15 compounds (93%). All 15 compounds could be separated by at least one cyclofructan column. Five compounds could be partially or fully separated by all three CSPs. The effect of ethanol, 2-propanol and butanol as 5 and 10% v/v polar modifiers in heptane was studied. A prototype 15?cm?×?4.6?mm column packed with superficially porous 2.7?µm CF6-P bonded particles was tested with the same set of compounds and a standard HPLC system. The increased efficiency and solvent saving were significant.     

聚合物负载的手性联二萘酚的合成及其在不对称催化中的应用进展

作为一种有机配体, 手性1,1'-联二萘酚(BINOL)被广泛应用于过渡金属催化的均相不对称有机反应. 为克服均相催化剂不易回收重复使用等缺陷, 人们深入研究了聚合物负载手性BINOL催化剂的方法. 总结了近年来聚合物负载手性BINOL催化剂的合成及其在不对称有机催化中的应用, 并对负载型BINOL催化剂进行了展望.     

Control over the chirality of (R)-1,1'-bi-2-naphthol dibenzoate in nanoparticles

Nanoparticles of (R)-1,1′-bi-2-naphthol dibenzoate (R-BND) ranging from 40 to 170 nm were prepared by using the reprecipitation method. The nanoparticles exhibit size-dependent exciton chirality, where the coupling potential V₁₂ of ¹B_b transitions increases as nanoparticles grow and simultaneously the exciton chirality peaks exhibit the bathochromic shift. Such size-dependent optical properties can be attributed to the lattice hardening with increased particle size, which leads to a decreased dihedral angel θ between the two naphthyl planes in a R-BND molecule.     

Synthesis of New and Novel N-Protected 1-Aminoalkyl-2-naphthol Derivatives

A series of three-component reactions has been carried out using HClO₄-SiO₂ as a versatile heterogeneous catalyst. A series of new and novel N-protected 1-aminoalkyl-2-naphthol derivatives have been prepared under thermal solvent-free reaction conditions. In all cases, the reaction conditions were very simple and high-yielding.     

磺化聚醚砜的制备及对异丁烷的丁烯烷基化催化性能

磺化聚醚砜的制备及对异丁烷的丁烯烷基化催化性能     

改性X型沸石催化甲苯、甲醇侧链烷基化反应的研究进展

综述了三十年来国内外有关在改性Ｘ型沸石催化剂上,甲苯、甲醇侧链烷基化制备苯乙烯反应的研究状况。经过性改性的Ｘ型沸石具有合适的孔径和适当强度及数量的表面酸碱中心、表面酸碱中心的协同作用有利于反应活性及选择性的提高。参考文献１２６篇。     

Preparation of 1-amidoalkyl-2-naphthol derivatives using barium phosphate nano-powders

Barium phosphate(Ba₃(PO₄)₂) nano-powder was successfully synthesized via a simple precipitation route without any surfactant. The prepared nano-powder was applied for the facile synthesis of 1-amidoalkyl-2-naphthol derivatives using multi-component reaction of aldehydes, 2-naphthol and an amide(or urea) in high yields.     

Alkylation of aniline withn-propyl alcohol over zeolites

The alkylation of aniline withn-propyl alcohol over ZSM-5 and Y zeolites has been studied. Ce-exchanged Y zeolites proved to be the most active for the alkylation of aniline byn-propyl alcohol. The reaction of N-propylaniline over zeolites has been investigated. N-alkylaniline decomposed over zeolites to aniline and alkene, which in turn rearrange to C-alkylanilines.n-Propyl derivatives were formed through an SN₂ type mechanism, while isopropyl derivatives were formed by an SN₁ type mechanism.     

Formation of chiral charge-transfer complex with axially chiral 1,1′-bi-2-naphthol and viologen derivatives

By using three types of viologen derivatives, we synthesized chiral charge-transfer (CT) complexes with an axially chiral 1,1′-bi-2-naphthol molecule and successfully controlled the crystal structure and inclusion ability of the third component by changing the viologens.     

Complex formation of certain rare earth metals with 1-(2-pyridylazo)-2-naphthol (PAN) in alcohol-water solutions

The formation ofPAN complexes in the systems:Ln(III)—PAN—alcohol—water [whereLn(III) = Pr, Nd, Sm, Eu, Gd, Tb, alcohol - ethanol andLn(III) = Eu, alcohol =n-propanol, isopropanol] was investigated by a spectrophotometric method. Equilibrium constants for the reactionLn ³⁺+HLLnL ²⁺+H⁺ (HL =PAN) and stability constants of complexesLnL ²⁺ are reported.

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Komplexbildung einiger Seltenerdmetalle mit 1-(2-Pyridylazo)-2-naphthol (PAN) in alkoholisch-wäßrigen Lösungen

Zusammenfassung Die Bildung der Komplexe vonPAN in den SystemenLn(III)—PAN—Alkohol—Wasser [Ln(III) = Pr, Nd, Sm, Eu, Gd, Tb, Alkohol = Ethanol undLn(III) = Eu, Alkohol =n-Propanol, Isopropanol] wurde mit einer spektrophotometrischen Methode untersucht. Die Gleichgewichtskonstanten der ReaktionenLn ³⁺+HLLnL ²⁺+H⁺ (HL =PAN) und die Stabilitätskonstanten der KomplexeLnL ²⁺ wurden berechnet.

     

Phase-transfer oxidation of 2-methyl-1-naphthol into 2-methyl-1,4-naphthoquinone in the presence of vanadomolybdophosphoric heteropolyacids

2-Methyl-1-naphthol is oxidized into 2-methyl-1,4-naphthoquinone (menadione) by air in the presence of vanadomolybdophosphoric heteropolyacids and their salts. The reaction proceeds in a biphasic system, and the yield of menadione is up to 85 %. The influence of the composition of the heteropolyacids on the rate and the selectivity of the reaction was studied, and the reaction mechanism was proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1208–1211, July, 1994.     

SiO_2改性MCM-22分子筛上联苯与环己醇的择形烷基化反应

以正硅酸四乙酯(TEOS)为修饰剂,采用化学液相沉积法(CLD)对MCM-22分子筛进行改性,制备了一系列SiO_2改性的MCM-22催化剂。采用X射线衍射(XRD)、N_2物理吸附-脱附、氨程序升温脱附(NH_3-TPD)、吡啶吸附红外光谱(Py-IR)对催化剂性质进行了表征。结果表明SiO_2主要沉积在MCM-22分子筛的外表面,外表面上的Br?nsted酸位量明显减少,但对分子筛的总酸量影响不大。考察了改性催化剂用于联苯与环己醇的择形烷基化反应制备线性4-环己基联苯(4-CBP)及4,4′-环己基联苯(4,4′-DCBP)的催化性能。在常压条件下,温度为190°C时反应200 min,4-CBP与4,4′-DCBP的选择性分别为80.4%与63.7%。结合表征数据,发现SiO_2沉积对发生在催化剂外表面Br?nsted酸位上的异构化反应有明显的抑制作用。此外,重复使用5次后的改性分子筛经过焙烧复原,活性与选择性基本恢复。