取代苯甲醛类的Knoevenagel反应的研究

苯环上有吸电子基团(p-或m-HO_2,p-CN,m-Br)取代的苯甲醛与甲基丙二酸在吡啶催化下,生成α-甲基-β-羟基苯丙酸类化合物;在六氢吡啶催化下则得到α-甲基肉桂酸类化合物。取代苯甲醛与丙二酸无论用吡啶或六氢哟啶催化均生成肉桂酸类化合物;与丙二酸二乙酯缩合时也无论用吡啶或六氢吡吡催化均生成苄叉丙二酸二乙酯。     

取代苯甲醛的取代基在硝基苄基鏻参与的Wittig反应中对二苯乙烯分子构型的影响

用硝基苄基鏻与取代苯甲醛经Wittig反应合成了一系列含硝基的二苯乙烯型化合物.研究表明,用硝基苄基鏻在二氯甲烷中进行这类Wittig反应时,随着苯甲醛的取代基不同,得到二苯乙烯主要产物的构型不同,取代基为NMe2,OMe,Me,Cl,H等时主要得到E式产物,取代基为CN和NO2等时主要得到Z式产物;进一步比较3种苄基鏻原料分别与6种不同取代苯甲醛反应后产物的Z/E比,发现用含硝基的苄基鏻作原料时,随苯甲醛上取代基的吸电子效应减小,产物的Z/E比也减小,而用苄基鏻或对甲基苄基鏻作原料时,没有观察到这种Z/E比减小的趋势.通过测定产物的晶体结构,确证了6个目标化合物的分子构型,另外通过核磁共振谱、气-质联用色谱、紫外光谱和红外光谱对各二苯乙烯化合物的结构进行了详细表征.     

有机磷化合物的研究 XV.合成α-氨基取代苄基膦酸的新方法

在三氟化硼催化下,二乙基磷酰胺、取代苯甲醛和亚磷酸三苯酯反应生成α-二乙基磷酰氨基取代苄基膦酸二苯酯(1),再经溴化氢的乙酸溶液处理,能选择性除去氨基上的保护基,得到相应的α-氨基取代苄基膦酸二苯酯溴化氢盐(2).2可视可合成膦酸肽的中间体,继续酸性水解可得α-氨基取代苄基膦酸(3).这个新的合成方法具有操作简便和产物纯度及得率均较高的特点。     

非对称取代卟啉锌、镉的生成反应动力学及动力学盐效应研究

本文报道应用停流方法对非对称取代卟啉［5-(4-乙酰氨基苯基)-10,15,20-三(4-甲基苯基)卟啉］(H₂T(p-CH₃)₃(p-NHCOCH₃)PP)与Zn(Ⅱ)、Cd(Ⅱ)在丙酮中的生成反应动力学进行了研究,提出了反应机理,并用非线性拟合和线性拟合的方法求得了生成反应各基元步骤的动力学参数,同时还探讨了温度,溶剂效应、动力学盐效应对反应体系的影响,并对锌、镉两种卟啉在生成机理及生成反应速率上的差异给予了解释。     

碱性介质中二过碲酸合铜(III)氧化乙二醇的反应动力学及机理

本文采用分光光度法研究了碱性介质中二过碲酸合铜(III)(DTC)氧化乙二醇(Glgcol)在291.2-303.2K的反应动力学机理。结果表明, 反应对氧化剂(DTC)是一级, 对乙二醇也是一级, 准一级([Glycol]0>>[DTC]0)速率常数Kobs随着[OH^-]增加而增加, 随着[TeO4^2^-]增加而降低, 并且有负盐效应, 提出了一种含有前期平衡的反应机理。据此导出了一个能够解释全部实验事实的速率方程, 求出平衡常数、速控步骤的速率常数及298.2K时的活化参数。     

取代苯甲醛肟羧酸酯的合成及生物活性研究：I.取代苯甲醛肟二氯菊酸酯 …

探讨了α－取代苯甲醛肟合成的新方法，合成了２０种新型菊酸肟酯类化合物，并对其进行了初步生物活性测试，化合物５ａ，５ｆ具有很好的抗病毒活性。     

碱性介质中二过碲酸合铜(III)氧化乙二醇的反应动力学及机理

本文采用分光光度法研究了碱性介质中二过碲酸合铜(III)(DTC)氧化乙二醇(Glgcol)在291.2-303.2K的反应动力学机理。结果表明, 反应对氧化剂(DTC)是一级, 对乙二醇也是一级, 准一级([Glycol]0>>[DTC]0)速率常数Kobs随着[OH^-]增加而增加, 随着[TeO4^2^-]增加而降低, 并且有负盐效应, 提出了一种含有前期平衡的反应机理。据此导出了一个能够解释全部实验事实的速率方程, 求出平衡常数、速控步骤的速率常数及298.2K时的活化参数。     

取代苯甲醛肟羧酸酯的合成及生物活性研究──Ⅰ.取代苯甲醛肟二氯菊酸酯的合成及生物活性

探讨了α-取代苯甲醛肟合成的新方法,合成了20种新型菊酸肟酯类化合物,并对其进行了初步生物活性测试,化合物5a,5f具有很好的抗病毒活性.     

苯甲醛与乙酰丙酸乙酯反应产物酸的高效液相色谱分析

建立了苯甲醛与乙酰丙酸乙酯亲核加成反应目标产物酸的高效液相色谱分析方法。色谱柱为C18柱,流动相为体积比60∶40的甲醇-0.02%甲酸水溶液,流速为0.6mL/min,柱温为室温,检测波长为270nm。在上述条件下两种目标产物分别在1～300μg/mL和1～600μg/mL的范围内与色谱峰面积之间呈良好线性关系;回收率分别为101.0%～102.1%和97.4%～104.0%。该方法简便、快速、准确,为不饱和有机酸类同分异构体的分析提供了一定参考。     

Reactions of dialkyl phosphonates and phosphonates with bis(benzylideneimino)toluene

Dialkyl phosphonates bind to the C=N bond of bis(benzylideneimino)toluene, with formation of dialkyl (benzylideneimino)benzylaminobenzyl phosphonates. The complicated character of IR spectra of these compounds is connected with the possibility of formation of dimeric cyclic associates and intramolecular hydrogen bonding. Phosphinic acid reacts with bis(benzylidenimino)toluene in a 2: 1 ratio to affordN,N-benzylidenebis(-amino-benzytphosphonic) acid.Translated fromIzvestiya Akademii Nouk. Seriya Khimicheskaya, No. 5, pp. 1303–1305, May, 1996.     

Solvent effects on SN2 reaction between substituted benzyl chloride and chloride ion

The effects of solvent on S_N2 reaction between some substituted benzyl chlorides and chloride ion have been investigated by DFT and ab initio methods using the polarizabale continuum model. The activation energies are higher in the solution media relative to the gas phase and grow by the increase in the dielectric constant of solvent. The complexation energies in solution media are smaller than those in the gas phase and reduce with increasing the dielectric constant. The energy data are in good agreement with the geometrical parameters and substituent constants. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Kinetics and mechanism of the reaction of substituted benzyl bromides with copper in dimethylformamide

The reaction of copper metal with various substituted benzyl bromides in dimethylformamide has been studied and the kinetic and thermodynamic parameters of the reaction have been obtained. Hammett plots of log(k/k°) vs the substituent constant σ gave good correlations (ρ = 0.24, S_ρ = 0.03, r = 0.951). The structure of the organic group has little effect on the rate of reaction of substituted benzyl bromides with copper. In the absence of atmospheric oxygen, oxidative dissolution of copper occurred by the mechanism of single‐electron transfer with the formation of 1,2‐diphenylethanes and copper(I) complexes. The stereochemistry and intermediate compound were also studied and the reaction mechanism is discussed. Copyright © 2005 John Wiley & Sons, Ltd.     

单重态CCl~2与O~3反应的热力学及动力学性质研究

在量化计算的基础上运用统计热力学和Wigner校正的Eyring过渡态理论研究了不同温度下单重态CCl~2和臭氧O~3反应的热力学及动力学性质。计算结果表明该反应在低温下具有热力学优势,而在高温下具有动力学优势。     

次甲基硅SiH与HF反应的热力学及动力学性质研究

在量子化学对SiH与HF反应计算的基础上,运用统计热力学和Wigner校正的Eyring过渡态理论计算了该反应在200～2000K温度范围内的热力学函数、平衡常数、频率因子A和速率常数随温度的变化。计算结果表明该反应在低温下具有热力学优势,而在高温下具有动力学优势。该反应在研究的温度范围内是一放热、熵减少的反应,反应的速率常数随温度的升高而增大,且服从Arrhenius定律。     

Modified horner–emmons reaction of polymeric phosphonates: Versatile synthesis of pendant stilbene-containing polymers

Poly[styrene-co-(diethyl vinylbenzylphosphonate)] and poly[methylmethacrylate-co-(diethyl vinylbenzylphosphonate)] were prepared and used in modified Horner-Emmons reactions to synthesize polymers with covalently attached stilbene groups. This versatile new method allowed for the preparation of polymers with either electron-donor (OCH₃, CH₃) or electron acceptor (Br, NO₂) substituents on the stilbene aromatic ring. The resulting polymers were characterized by ¹H NMR, FT-IR, UV-visible, DSC, and size exclusion chromatography. Efficient transformation of polymeric phosphonates to the polymeric stilbene derivatives was realized. Size exclusion chromatographic analyses demonstrated that the reaction conditions have no deleterious effect on the molecular weight distribution of the various polymers that were prepared. Photochromic behavior was demonstrated for one of the derivatives. © 1995 John Wiley & Sons, Inc.     

Convenient synthesis of α,β-unsaturated phosphonates via a Mizoroki-Heck reaction of arylboronic acids with diethyl vinylphosphonate

Palladium acetate catalyzed Mizoroki-Heck reactions of arylboronic acids with diethyl vinylphosphonates afford α,β-unsaturated phosphonates in good yields.     

The efficient synthesis of 2-arylpyrimidine acyclic nucleoside phosphonates using Liebeskind-Srogl cross-coupling reaction

A series of novel acyclic nucleoside phosphonates with various aryls attached to the C-2 position of the pyrimidine moiety has been prepared using the Liebeskind-Srogl cross-coupling protocol. The reactions of highly functionalised 2-(methylsulfanyl)pyrimidines with various arylboronic acids were studied and optimised.     

Substituent effects on SN2 reaction between substituted benzyl chloride and chloride ion in gas phase

Nucleophilic substitution reaction between some substituted benzyl chlorides and chloride ion has been investigated by ab initio and DFT methods. New calculated energy data are in better agreement with experimental data. The electron‐withdrawing groups increase the energy barriers and the electron‐donating groups decrease them. The changes of geometrical parameters and energy data are in good agreement with the results of atoms in molecules and natural bond orbital analyses. The relationship between Hammett coefficients and energy data (and geometry parameters) has been established and the ρ constant has been calculated for this reaction. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011