新法合成硝基二苯醚化合物

改进了以聚乙二醇为催化剂相转移催化合成硝基二苯醚的方法，合成了９个４－硝基二苯醚化合物，结果表明，该方法反应过程平稳，产品收率高。     

Phase‐Transfer‐Catalyzed Olefin Isomerization/α‐Alkylation of α‐Alkynylcrotonates as a Route for 1,4‐Enynes

The phase‐transfer‐catalyzed alkylation of α‐alkynylcrotonates was developed as a means to provide 1,4‐enynes deconjugated by an all‐carbon quaternary center. Extension to the asymmetric version using the chiral phase‐transfer catalyst (S)‐ 3 provided the alkylated compounds with up to 87% ee.     

相转移催化合成N－取代硫代磷酰胺二乙酯

用乙基氯化物（Ｏ，Ｏ－二基硫代磷酰氯）与不同的胺反应，以碱酸钾作缚酸剂、季铵盐作相转移催化剂，合成了六种Ｎ－取代硫代磷酰胺二乙酯，其结构经ＩＲ、ＮＭＲ和元素分析证实。     

Synthesis of sulfonated rubber ionomers by the ring‐opening reaction of epoxidized styrene–butadiene rubber,their characterization,and their properties

A novel method for the synthesis of the sulfonate ionomer of styrene‐co‐butadiene rubber (SBR) was developed. SBR was first epoxidized by performic acid formed from hydrogen peroxide and formic acid in situ in solution, and this was followed by a ring‐opening reaction with an aqueous solution of NaHSO₃. The optimum conditions for the epoxidation of SBR in the presence of a phase‐transfer catalyst and for the ring‐opening reaction of epoxidized SBR with an aqueous solution of NaHSO₃ were studied. During the epoxidation of SBR, a phase‐transfer catalyst, such as poly(ethylene glycol), could enhance the conversion of double bonds to epoxy groups. During the ring‐opening reaction, both the phase‐transfer catalyst and ring‐opening catalyst were necessary to enhance the conversion of the epoxy groups to ionic groups. The addition of Na₂SO₃ to the reaction mixture was important to obtain 100% conversion. The products were characterized with Fourier transform infrared spectrophotometry, ¹H‐NMR spectroscopy, differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). DSC showed that the sodium sulfonate SBR ionomer possessed a dissociation temperature of ionic domains at 110°C, which appeared as black spots under TEM, after the sodium ions of the ionomer were substituted by lead ions. Some properties of the sodium ionomer, such as the water absorbency, oil absorbency, and dilute solution behavior, were studied. With increasing ionic groups, the water absorbency of the ionomer increased, whereas the oil absorbency decreased. The dilute solution viscosity of the ionomer increased abruptly with increasing ionic group content. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3090–3096, 2006     

N,N-二乙基氨基乙基-4-甲基苄基醚及其类似物的合成

采用相转移催化的方法合成了5个N,N-二烷基氨基乙基-4-甲基苄基醚化合物,产率为73%~89%。适宜的反应条件是:以二烷基氨基乙醇、4-甲基氯化苄为原料,四丁基溴化铵为相转移催化剂(PTC),氢氧化钠为碱,甲苯为溶剂,摩尔比n(R1R2NCH2CH2OH)∶n(MeArCH2C1)∶n(NaOH)∶n(PTC)=1.1∶1∶2∶0.05,反应时间为2 h,温度为70℃。产物经过沸点、元素分析、红外光谱、氢质子核磁共振谱给予确证。     

微波辐射相转移催化合成十二烷基缩水甘油醚

采用微波辐射技术,以四丁基溴化铵为相转移催化剂催化合成了十二烷基缩水甘油醚,研究了微波功率、辐射时间、反应物配比对反应产物收率的影响。实验结果表明,适当的微波辐射可以加速十二烷基缩水甘油醚的合成反应,而且产率高,操作简便。     

3,5‐Bis(n‐perfluorooctyl)benzyltriethylammonium Bromide (F‐TEBA): An Efficient,Easily Recoverable Fluorous Catalyst for Solid‐Liquid PTC Reactions

A readily available 3,5‐bis(perfluorooctyl)benzyl bromide and triethylamine were reacted under mild conditions to give 3,5‐bis(n‐perfluorooctyl)benzyltriethylammonium bromide ( F‐TEBA ), an analogue of the versatile phase‐transfer catalyst, benzyltriethylammonium chloride (TEBA), containing two fluorous ponytails. This perfluoroalkylated quaternary ammonium salt was successfully employed as a catalyst in a variety of reactions run under solid‐liquid phase‐transfer catalysis (SL‐PTC) conditions. Thus, being both hydrophobic and lipophobic, F‐TEBA could be quickly recovered in quantitative yields, and reused without loss of activity over several reaction cycles.     

扁桃酸及其类似物合成的相转移催化剂筛选

以芳香醛和氯仿为原料，经相转移催化反应合成扁桃酸及其类似物。考察了在相同的反应温度，反应时间，催化剂用量，反应物配比，不同催化剂对反应收率的影响。发现四丁基氯(溴)化铵催化合成产率最高。     

微波辐射相转移催化合成苯甲酸正丁酯

研究了在四丁基溴化铵催化下，采用微波辐射由苯甲酸钠和溴代正丁烷发生亲核取代反应合成苯甲酸正丁酯。讨论了微波辐射功率、辐射时间、原料配比及催化剂用量等对酯化反应的影响。结果表明：当n（苯甲酸钠）：n（溴代正丁烷）：n（四丁基溴化铵）为1．0：3．0：0．3时，采用280W微波辐射55min，苯甲酸正丁酯的产率可达93．4％。     

PEG-600在有机合成中的应用及前景

综述了PEG-600的结构及作用机理,介绍了其作为相转移催化剂在固-液,三相,配合超声波、微波等在有机反应中的应用,并对PEG-600在该领域的前景进行了展望.     

Optical Activity Related to Ordered Aggregation in Some Biological Molecules: I. Poly(L-proline) and Collagen

Abstract

Optical activity, due to differential light scattering, is shown to produce large effects on the circular dichroism (CD) spectra of several biopolymers. It is suggested that helical association on aggregation is the causative factor. Thus, under the salt conditions for formation of native fibrils of collagen from solution, new CD bands are found to appear and intensify with time. Similarly, in the case of polyproline I, M = 13,500 (thought to associate in a side-to-side manner), large CD bands are observed throughout the visible and UV spectrum in addition to the normal CD bands of the unassociated form. These bands can be related to scattering phenomena. The new bands appear to be overtones of a fundamental frequency, similar, in some respects, to Bragg X-ray diffraction from crystals, and not to be confused with the ordinary Duysens absorption flattening effect on the CD spectra that is theoretically calculable from Mie scattering of spherical aggregates. It does, however, correspond to the optical activity observed in liquid crystals.     

Liquid‐Liquid‐Liquid Phase Transfer Catalysis: A Novel and Green Concept for Selective Reduction of Substituted Nitroaromatics

The selective reduction of nitroaromatics to the corresponding amines is an important transformation since many aromatic amines exhibit biological activities and find a multitude of industrial applications, being intermediates for the synthesis of dyes, pharmaceuticals and agrochemicals. A variety of nitroaromatics dissolved in organic solvents was reduced by using aqueous sodium sulfide, and tetrabutylammonium bromide (TBAB) as the phase transfer catalyst by choosing appropriate concentrations which resulted in three immiscible liquid phases. Compared to L‐L PTC, the L‐L‐L PTC offers much higher rates of reaction, better selectivities and repeated use of catalyst. The selectivities for the desired products were 100%.     

Enantioselective Phase‐Transfer Catalytic α‐Benzylation and α‐Allylation of α‐tert‐Butoxycarbonyllactones

A new enantioselective α‐benzylation and α‐allylation of α‐tert‐butoxycarbonyllactones was devloped. α‐Benzylation and α‐allylation of α‐tert‐butoxycarbonylbutyrolactone and α‐tert‐butoxycarbonylvalerolactone under phase‐transfer catalytic conditions (50% cesium hydroxide, toluene, −60 °C) in the presence of (S,S)‐3,4,5‐trifluorophenyl‐NAS bromide (1 mol%) afforded the corresponding α‐substituted α‐tert‐butoxycarbonyllactones in very high chemical yields (up to 99%) and optical yields (up to 99% ee). The synthetic potential of this method has been successfully demonstrated by the asymmetric synthesis of unnatural α‐quaternary homoserines, 3‐alkyl‐3‐carboxypyrrolidine and 3‐alkyl‐3‐carboxypiperidine.     

相转移催化合成N,N-二烷基氨基乙基-4-乙氧基苄基醚

用相转移催化法合成了标题化合物,产率69%～82%。适宜的反应条件是:以4-乙氧基氯化苄、二烷基氨基乙醇为原料,在固体氢氧化钠作用下,四丁基溴化铵为相转移催化剂,甲苯为溶剂,物质的量比n(R1R2NCH2CH2OH):n(EtOArCH2Cl):n(NaOH):n(PTC)=1:1:2:0.05,反应时间2h,温度70℃。产物经过沸点、元素分析、红外光谱、氢质子核磁共振谱给予确证。     

同一体系相转移催化法合成二烯丙基三硫和二烯丙基二硫

在同一反应体系中以硫代硫酸钠和烯丙基氯为原料,分别以聚乙二醇-400(PEG-400)和十六烷基三甲基溴化铵(CTMAB)为相转移催化剂(PTC),合成大蒜油中的两种主要成分二烯丙基三硫(DATS)和二烯丙基二硫(DADS).探讨了相转移催化剂种类、pH、物料比对反应产物的影响.     

Silica Immobilized Second Generation Hoveyda‐Grubbs: A Convenient,Recyclable and Storageable Heterogeneous Solid Catalyst

The second generation Hoveyda–Grubbs metathesis catalyst was successfully immobilized on silica in pellet and powder form following a practical and fast synthesis procedure. The activity of the solid system is truly heterogeneous, efficient in various metathesis reaction types and stable for at least 4000 TON. Ru contamination of the products was very low (ppb levels). The successful use of the robust system has been demonstrated in a continuous reactor set‐up.     

Non‐Racemic Halohydrins via Biocatalytic Hydrogen‐Transfer Reduction of Halo‐Ketones and One‐Pot Cascade Reaction to Enantiopure Epoxides

Biocatalytic hydrogen‐transfer reduction of α‐chloro‐ketones furnished non‐racemic chlorohydrins by employing either Rhodococcus ruber as lyophilized cell catalyst or an alcohol dehydrogenase preparation from Pseudomonas fluorescens DSM 50106 (PF‐ADH). For all substrates investigated, Rhodococcus ruber gave strictly the “Prelog” product, whereas PF‐ADH showed scattered stereopreference. One possibility for a follow‐up reaction of halohydrins is the ring closure to the corresponding epoxide. A novel “one pot‐one step strategy” was employed to obtain the enantiopure epoxide from the α‐chloro‐ketone in a cascade like fashion at pH>12 involving biocatalytic hydrogen transfer reduction and in situ chemo‐catalyzed ring closure.     

Phase‐Transfer‐Catalyzed Enantioselective Mannich Reaction of Malonates with α‐Amido Sulfones

The highly enantioselective reaction between in situ generated, Cbz‐protected azomethines and malonates in the presence of 150 mol % of potassium carbonate (50 % w/w) and 1 mol % of quinine‐derived quaternary ammonium bromides as phase‐transfer organocatalysts has been developed. This study reports a novel approach for the asymmetric Mannich‐type reaction and a wide range of azomethines, including those derived from enolizable aldehydes, is tolerated by the present system. The adducts, obtained in excellent yields with ee up to 98 %, are suitable precursors of optically pure β‐amino acids.     

Synthesis of polymer‐supported quaternary ammonium salts and their phase‐transfer catalytic activity in halogen‐exchange reactions

Polymer‐supported quaternary ammonium salts were prepared, and their applications as phase‐transfer catalysts in aqueous organic systems were investigated. The polymer‐bound phase‐transfer catalysts were prepared with polystyrene resins crosslinked with the bifunctional monomers divinylbenzene and 1,4‐butanediol dimethacrylate. The polymers were functionalized with chloromethyl groups and quaternized with trialkylamines having different alkyl chains. The obtained phase‐transfer catalysts were characterized with IR spectroscopy and elemental analysis. The thermal stability was also determined by the thermogravimetric method. The catalytic properties of the phase‐transfer catalysts were studied in halogen‐exchange reactions. The effects of the nature and extent of crosslinking of the polymer support, the alkyl groups of the trialkylamine, and the reaction conditions were investigated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci 2009     

涤纶催化织物的制备及其在醚合成反应中的应用

以五元丙烯酸酯共聚物为改性剂，涤纶织物为载体，通过浸轧整理制备了负载型涤纶相转移催化织物，分析了催化织物在Williamson醚合成反应中的催化性能与反应机理，考察了整理工艺、改性剂结构、负载量对催化活性的影响。结果表明，磷酸与甘油可提升改性剂分子的交联程度，从而提高催化织物的稳定性；改性剂中长链烷基酯为甲基丙烯酸十八酯、阳离子单体为甲基丙烯酰胺丙基二甲基丁基溴化铵、阳离子单体摩尔用量为13.33%、负载量为20%时，织物催化活性最佳；催化织物可吸附油相于其表面，随后引发离子交换、成键反应；在应用于不同苯酚的Williamson醚合成反应时，产率均可达92%以上，催化织物在回用10次时仍具有较高的催化活性。