烯丙基硅烷的一步法合成研究

采用一步合成方式,将3-溴丙烯与金属镁在以甲苯和供电子溶剂(乙醚或THF)构成的混合溶剂中进行反应,继而与四氯化硅反应,成功合成了四烯丙基硅烷,其产率在乙醚与3-溴丙烯的摩尔比为4(V甲苯/V乙醚=1·1)时达到极值,超过了91%。研究同时发现,选择THF代替乙醚时,同样在THF与3-溴丙烯的摩尔比为4(V甲苯/VTHF=1·7)时产率达到极值(63·12%)。本过程可提高产率,降低成本,是一条好的生产四烯丙基硅烷的路线。     

氟烯的结构-特性关系——Ⅴ.若干取代α,β,β-三氟苯乙烯和α,β,β-三氟萘乙烯的合成——它们的~(19)F核磁共振参数与“歪电子云”概念之间的联系

本工作的目的是:(1)利用苯基格氏试剂与四氟乙烯合成α、β、β-三氟苯乙烯(TFS)的新方法~([3])来制备取代的TFS与α、β、β-三氟萘乙烯(TFEN);(2)根据“歪电子云”模型~([4]),研究各取代的TFS的~(19)F NMR参数与取代基的Hammett常数之间的线性关系. 比较了TFS在四氢呋喃(THF)、乙醚、二氧陆环和乙二醇二甲醚中的产率和相应的格氏试剂产率,其中以在THF中合成的TFS的产率最高。因此.六个取代的TFS和TFEN均在THF中合成,所得到的产物为1,2。产物结构经元素分析、~(19)F NMR、IR和UV鉴定,其中1b、1e、1g、1i、2g和2i为新化合物,产率见表1。     

格氏反应制备醇实验的改进

对有机化学必修实验“格氏反应制备醇”进行了研究。采用四氢呋喃(THF) 替代无水乙醚做反应溶剂,对教材中实验的试剂无水处理、反应的引发、试剂的用量、反应的后处理、产品的重结晶及用薄层色谱(TLC)检测产品纯度等进行了探讨和改进。结果表明,在THF中进行格氏反应制备三苯甲醇,实验现象明显,产率较高,降低了实验成本,全面提高了学生综合实验能力。     

锡粉促进下由醛、芳甲酰肼和烯丙基溴“一锅法”合成高烯丙基酰肼化合物

报道了锡粉促进下,以四氢呋喃(THF)为溶剂,在室温条件下,通过醛、芳甲酰肼和烯丙基溴"一锅法"反应,合成高烯丙基酰肼化合物的方法.该方法具有条件温和,不使用任何催化剂,操作简单,产率高等优点.     

丙酮氰醇为氰源的卤代烃的氰基取代反应研究

氰基取代反应是有机合成中引入氰基官能团的重要方法.以丙酮氰醇为氰化试剂,以脂肪族卤代烷R-X (X=Cl,Br,I)为底物,通过亲核取代反应合成一系列氰基化合物.研究结果表明,在50℃下四氢呋喃(THF)与1,3-二甲基咪唑啉酮(DMI)(体积比为3∶1)组成的混合物为反应溶剂,LiOHoH2O为碱,丙酮氰醇与相应的卤...     

杂多酸催化H2O/THF或乙醚中三组分一锅煮合成α-胺基膦酸酯

发现杂多酸是在水/四氢呋喃或乙醚中三组分一锅煮高产率合成α-胺基膦酸酯的有效催化剂.研究了催化剂用量、反应溶剂、醛和胺的结构对反应的影响.     

聚(N-乙烯基己内酰胺)在二元水溶液中的温度响应性相变行为

用浊度法研究了聚(N-乙烯基己内酰胺)(PNVCL)在不同浓度的几种非质子溶剂如二甲基亚砜(DMSO)、N,N-二甲基甲酰胺(DMF)、四氢呋喃(THF)、1,4-二氧六环和质子溶剂(几种低级醇)的水溶液中低临界溶液温度(LCST)的变化情况.结果表明:PNVCL的LCST随DMF、THF、1,4-二氧六环和CH3OH...     

苯丙炔酸低聚物的合成及性能

极性-共轭双取代乙炔-苯丙炔酸在Pd(PPh3)2Cl2催化下直接通过易位催化机理聚合为低聚物.单体苯丙炔酸由两步制得,先通过液溴和肉桂酸的加成反应得到二溴代苯丙酸,然后消去两分子溴化氢得到单体.通过红外光谱(IR)、核磁共振(NMR)对单体及低聚物的结构进行了表征.凝胶渗透色谱(GPC)结果显示,聚合反应以甲苯作溶剂,75℃下效果最好,产率中等.这种共轭低聚物可以溶于四氢呋喃(THF)等极性溶剂,TGA结果表明低聚物热稳定性高.紫外可见吸收光谱(UV-Vis)显示,由于聚合后共轭主链大大增长,苯丙炔酸低聚物骨架上电子的跃迁使得低聚物的四氢呋喃溶液在波长高于310 nm光谱的区域中有吸收.荧光光谱(FS)显示,低聚物的四氢呋喃溶液在342 nm激发光下发蓝光,420 nm处有特征荧光发射峰.     

PP14TFSI离子液体在可充镁电池电解液的应用

制备了可充镁电池电解质苯酚基镁盐,以四氢呋喃（THF）与N-甲基-N-丁基-哌啶-双三氟甲基磺酰胺（PP14TFSI）离子液体混合物代替四氢呋喃作为该电解质的溶剂. 当THF与PP₁₄TFSI体积配比为1:1时,该苯酚基镁盐电解液镁可逆溶出性能最佳,电化学窗口宽（2.7 V vs. Mg）,离子电导率高（7.77 mS·cm^-1）. 此外,热重测试表明离子液体的加入大大降低了THF溶剂的挥发性,提高了可充镁电池的安全性能. 四氢呋喃 + N-甲基-N-丁基-哌啶-双三氟甲基磺酰胺混合溶剂有望作为可充镁电池电解液的首选溶剂.     

聚丁二烯1,2-结构含量和SBS中聚丁二烯段1,2-结构含量的调节

以正丁基锂为引发剂,环己烷为溶剂,研究了四氢呋喃(THF)对聚丁二烯1,2-结构和丁苯嵌段共聚物SBS中聚丁二烯段1,2-结构含量的影响,指出在一定温度下,聚丁二烯1,2-结构含量与体系中THF的浓度有指数关系。控制体系中THF的浓度和聚合反应温度,可调节聚合产物中聚丁二烯1,2-结构含量。     

Etude de l''influence du diluant hydrocarbone dans la reaction des organomagnesiens primaires sur les cetones encombrees

Primary alkylmagnesium bromides are prepared in hydrocarbon solutions such as benzene or toluene using 1 equivalent of diethyl ether or tetrahydrofuran. Their reactions with diisopropylketone and cyclohexylisopropylketone increase drastically the addition products in comparison with the reactions in diethyl ether or in tetrahydrofuran. No important differences were found in the distribution of reaction products between diethylether or tetrahydrofuran and between benzene and toluene when they are used as complexant and diluent respectively.     

Mechanism for the formation of gas-phase protonated alcohol-ether adducts by VUV laser ionization and density-functional calculations

The neutral vapors above liquid alcohol/ether mixtures, (diethyl ether/methanol, diethyl ether/ethanol, tetrahydrofuran/methanol, and tetrahydrofuran/ethanol) were co-expanded with He in a supersonic jet, ionized with a 118-nm vacuum ultraviolet laser, and detected in a time-of-flight mass spectrometer. In each case, features attributed to protonated alcohol-ether dimers and protonated ether monomers were observed, as well as those ions obtained by ionizing neat alcohol or ether samples alone. Theoretical calculations, carried out to establish the energetics of the various possible reactions leading to the formation of the observed binary adducts, indicate that the most thermodynamically favorable pathway corresponds to the addition of a protonated alcohol monomer to neutral ether.     

Untersuchungen über das Verhalten organischer Mischphasen 9. Mitteilung Vergleich der binären Systeme Tetrahydrofuran mit Wasser,Methanol und Cyclohexan,Diäthyläther mit Wasser,Methanol und Cyclohexan und Tetrahydrofuran-Diäthyläther

Activities and mixing functions of the following binary systems at 25° C are discussed: 1. mixtures of tetrahydrofuran with water, methanol, and cyclohexane; 2. mixtures of diethyl ether with water, methanol, and cyclohexane, and 3. mixtures of tetrahydrofuran with diethyl ether. Comparison with similar systems shows that in systems containing methanol, the strongest interactions are formation and breaking of hydrogen bonds between alcohol molecules; interactions between methanol and ether molecules play a minor rǒle. Systems containing water exhibit two main kinds of interaction: formation and breaking of hydrogen bonds between water molecules, and formation of hydrogen bonds between water and ether molecules. Deviations from ideality are larger for diethyl ether than for tetrahydrofuran in water and methanol, and smaller in cyclohexane.     

Reactivity of dehydrometallophthalocyanines and -porphyrazines

The zinc dehydrophthalocyanine 2 and zinc dehydrobenzoporhyrazine 8 a were generated from the 1N-aminobenzotriazole-annulated zinc phtalocyanine 1 and zinc benzoporhyrazine 8, respectively, by oxidation with Pb(OAc)(4) in different solvents, for example, diethyl ether, tetrahydrofuran, acetic acid, and benzene. The reactivity of 2 and 8 a was studied in detail. These species not only easily undergo Diels-Alder additions with dienes, but also the used solvents can be added. Among the addition products with solvents ethoxy-, acetoxy-, acetoxybutyloxy-substituted and barrelen-fused phthalocyanines and benzoporpyrazines were isolated. No products resulting from the dimerization of two dehydro species were observed either for 2 or 8 a. Analysis of the reaction products in comparison with those obtained by oxidation of 1-aminobenzotriazole 15 under similar conditions proves a higher reactivity (electrophilicity) of the dehydro-PcZn 2 and dehydro-PzZn 8 a in comparison with unsubstituted benzyne towards the solvents used, such as diethyl ether and benzene.     

Kinetic and NMR spectroscopic studies of chiral mixed sodium/lithium amides used for the deprotonation of cyclohexene oxide

The mixed-metal complex formed from n-butylsodium, n-butyllithium, and a chiral amino ether has been studied by NMR spectroscopy. Three different mixed-metal amides were used as chiral bases for the deprotonation of cyclohexene oxide. The selectivity and initial rate of reaction were compared for sodium-amido ethers, lithium-amido ethers, and mixtures of sodium and lithiumamido ethers in diethyl ether and tetrahydrofuran, respectively. The mixed sodium/lithium amides are more reactive than the single sodium and lithium amides, whereas the stereoselectivities are higher when lithium amides are used. The alkali-metal/gamma-amido ethers exhibit both higher initial reaction rates and stereoselectivities than their beta-amido ether analogues. NMR spectroscopic studies of mixtures of n-butylsodium (nBuNa), n-butyllithium (nBuLi), and the gamma-amino ethers in diethyl ether show the exclusive formation of dimeric mixed-metal amides. In diethyl ether, the lithium atom of the mixed-metal amide is internally coordinated and the sodium atom is exposed to solvent; however, in tetrahydrofuran, both metals are internally coordinated.     

Polybenzopinacols. I. Photolytic coupling of aromatic diketones

Low molecular weight polybenzopinacols were obtained by the photolytic coupling of m- and p-dibenzoylbenzene and 4,4′-dibenzoyldiphenyl ether in isopropanol, tetrahydrofuran–isopropanol, benzene–isopropanol, and benzene–ethanol solutions. The polypinacols were soluble in common organic solvents such as tetrahydrofuran, ether, and benzene. The inherent viscosities ranged from 0.06 to 0.14. Average molecular weight (M?_n) data indicated that the polymers were mostly dimers and trimers.     

环氧乙烷-四氢呋喃共聚醚中环状齐聚物的气相色谱/质谱分析

首先将环氧乙烷（EO）-四氢呋喃（THF）共聚醚与二异氰酸酯反应，然后将未反应的环状齐聚醚（OCE）用乙醚萃取出来。经气相色谱/质谱（GC/MS）联机分析，鉴定出12个主要峰的结构组成，占总峰面积的96.42%。其中环状四聚体和环状五聚体的含量较高。     

Anionic polymerization initiated by diethylamide in organic solvents. I. The use of lithium diethylamide as a polymerization catalyst and the effect of solvent type on the polymerization of isoprene and styrene

Lithium diethylamide has been found to be an active initiator for the polymerization of isoprene both in hydrocarbon media and in a variety of polar solvents, such as diethyl ether and tetrahydrofuran. The successful initiation of styrene polymerization is, however, strongly dependent upon the type of solvent employed. Thus no polymerization is observed in hydrocarbon media or in diethyl ether solution, but polymerization occurs rapidly in either tetrahydrofuran or 1,2-dimethoxyethane solution. These polymerization processes are anionic in nature and are characterized by sigmoidal conversion–time plots, indicating that the initiation reactions are relatively slow compared to chain propagation.     

Studies on the synthesis of gymnodimine. Stereocontrolled construction of the tetrahydrofuran subunit

[reaction: see text]. A bis-(2,6-dichlorobenzyl) ether is shown to undergo efficient and highly stereoselective intramolecular iodoetherification to yield a cis-2,5-disubstituted tetrahydrofuran, thus providing a powerful illustration of a stereodirecting effect first noted by Rychnovsky and Bartlett. The tetrahydrofuran was transformed into a subunit suitable for incorporation into the shellfish toxin gymnodimine.     

Studies on the synthesis of (-)-gymnodimine. Subunit synthesis and coupling

Two principal subunits of the marine algal toxin (-)-gymnodimine were synthesized. A trisubstituted tetrahydrofuran representing C10-C18 of the toxin was prepared via a highly stereoselective iodine-mediated cyclization of an acyclic alkene bearing a bis-2,6-dichlorobenzyl (DCB) ether. The formation of a cis-2,5-disubstituted tetrahydrofuran in this process conforms to a stereodirecting effect by the DCB group proposed by Bartlett and Rychnovsky. A cyclohexene subunit corresponding to the C1-C8, C19-C24 portion of gymnodimine was synthesized via Diels-Alder cycloaddition of a 1,2,3-trisubstituted diene to a symmetrical dienophile obtained from Meldrum's acid. Differentiation of carbonyl groups in the cycloadduct was made by an intramolecular reaction with a neighboring alcohol to form a gamma-lactone. Linkage of the two subunits at C18-C19 was accomplished by using a B-alkyl Suzuki coupling in which a borane prepared from the pendent alkenyl chain of the cyclohexene domain was reacted with the (E)-iodoalkene attached at C16 of the tetrahydrofuran sector. Subsequent transformations positioned functional groups in the coupled product for a future macrocyclization event that would close the 15-membered ring of gymnodimine.