O-[3-(2′-或4′-吡啶)丙基]硫代磷(膦)酸酯及硫代磷酰胺酯类化合物的研究

用O,O-二烷基硫代磷酰氯,O-烷基胺基硫代磷酰氯及O-烷基(或芳基)苯基硫代膦酰氯与3-(2′-或4′-吡啶)丙醇缩合制备了相应的硫代磷酸脂,硫代磷酰胺酯共十八个新化合物。测定了它们的红外光谱和核磁共振谱,探索了适宜的反应条件及产物的提纯方法。经初步测试表明某些化合物具有植物激素的活性。     

二硫代氨基甲酸盐类和秋兰姆类化合物的反相纸上层析

一、前言近年来,二硫代胺基甲酸盐(dithiocarbamates)和秋兰姆(thiurams)类化合物的分离鉴定方法因纸上色层法之发展有了解决的途径。齐普(zijp)曾将二硫代胺基甲酸盐和秋兰姆用盐酸分解,然后用纸层法分离鉴定生成的仲胺。此法的缺点是:如不同试料分子两端的官能团相同,则生成之仲胺亦相同。故鉴定结果极不可靠。村上等用部分乙酰化的滤纸(乙酰度17.0％)分离此二类化合物,所得R_F值在0.47—0.73之间,故分离效果并不理想。金沢和佐藤以硅油(DC-550)和液体石蜡作反相,该法经笔者验证,所得结果大体相近,但对于二硫代胺基甲酸盐和秋兰姆间     

双(烷基环戊二烯基)二硫氰基钛、锆、铪的合成

文献报道了双(环戊二烯基)二硫氰基钛、锆、铪及双(甲基环戊二烯基)二硫氰基钛的合成。我们利用双(烷基环戊二烯基)二氯化钛、锆、铪与过量硫氰酸钾反应,合成了一系列新的双(烷基环戊二烯基)二硫氰基钛、锆、铪(见表1)。 (η~5-C_5H_4R)_2MCl_2+KCNS→(η~5-C_5H_4R)_2M(NCS)_2+KCl     

边界润滑条件下石墨与烷基硫代磷酸锌的协同作用

油溶性添加剂与团体润滑剂的相互作用是影响分散在润滑油中固体润滑剂作用的重要因素。本工作在SRV(微振动摩擦磨损)试验机和Falex试验机上考察了边界润滑条件下液体石蜡中石墨与极压抗磨添加剂二烷基二硫代磷酸锌(ZDDP)在摩擦、磨损及承载能力方面的相互影响,并在相同的条件下比较了石墨分别与极压抗磨添加剂磷酸三甲酚基酯(TCP)和二苄基二硫(DBDS)的相互影响。用表面辐廓仪、扫描电子显     

α-羰基硫代甲酰胺与溴的反应研究

报道了α 羰基硫代甲酰胺与溴在三乙胺存在下的反应 ,合成了二 [( 1 芳基亚胺基 1 苯甲酰基 )甲基 ]二硫醚类化合物 ,产率为 60 %～ 65 %.它们的结构经元素分析、红外光谱、核磁共振光谱和质谱分析得到确证     

二硫代胺基甲酸螯合剂(DTC)在高效液相色谱法中的应用

一、概述金属的二硫代胺基甲酸螯合物(以下简称DTC),随其中含氮基团的组成不同,可以区分为两类: 1.二级胺基团的R是憎水的烷基、芳香基等。这种配体与金属螯合之后,产物不溶于水,易溶于有机溶剂,如三氯甲烷、四氯化碳、二氯甲烷、乙醚、丙酮等。因而适于用萃取方法分离富集。 2.二级胺基团的R是亲水的羟基、羧基等,产物可溶于水、不溶于有机溶剂。上述两类螯合物,多具有一定的颜色,因而适于用分光光度法检测。另外,DTC螯合物一     

金属有机化合物的分析(Ⅴ)——双(烷基环戊二烯基)二卤化钛、锆、铪的纸色谱与核磁共振谱关系的研究

文献报导,仅Subbotina,A.I.等用纸色谱法研究了Cp_2TiCl_2与CpTiCl_5二化合物的分离。我们试图用薄层色谱法分离双(烷基环戊二烯基)二卤化钛、锆、铪化合物,未获成功。改用纸色谱法,取得良好的效果,并对各类化合物所得R_f值与它们的核磁共振谱的δ值之间的变化关系作了研究。     

稳定剂并用时的超加和性——Ⅰ.二烷基二硫代胺基甲酸镉盐与苯基-β-萘胺并用对天然橡胶热氧老化的影响

从二烷基二硫代胺基甲酸镉及其与苯基-β-萘胺并用提高天然硫化胶的抗热老化能力表明:由苯并噻唑基或二烷基二硫代胺基甲酸所生成的镉盐,在这方面所具有的作用,看来是一致的;但二烷基二硫代胺基甲酸镉与苯基-β-萘胺并用时,硫化胶抗热老化能力提高的超加和性,在100℃下较强,在120℃下,则不显著。 二烷基二硫代胺基甲酸镉(RCd)单独不氧化(140℃下)。当加入天然橡胶中,虽不产生诱导期,但极大地降低吸氧速度和吸氧量;且随RCd用量的增加,其吸氧速度和吸氧量而相应降低,保持最小吸氧量的时间延长。由此提出了RCd可能与橡胶氧化生成的最初产物作用,而消除了引发和增长氧化链反应的活性中心的假设。 苯基-β-萘胺140℃下的氧化动力学曲綫,与加在橡胶中的类似,只是诱导期稍长。绣导期过后,出现自动催化链反应特征。但加入RCd后,稍出现极微量的吸氧,而一直保持此极小吸氧量不变。两者同时加入天然橡胶中,则最初吸氧速度和保持最小吸氧量的时间,随两者分子比的对应变化而出现最大值。这些有力地证明:RCd对苯基-β-萘胺,不论有无橡胶,都能与其作用,抑制其本身的氧化。由此提出了假设:所研究并用体系超加和性出现的原因之一,乃是两者相互作用后,抑制了苯基-β-萘胺经氧化而引发氧化链反应的效应,从而充分发挥了苯基-     

聚全氟三嗪高温弹性体的核磁共振

含氟高温弹性体是六十年代发展的一项新材料。利用碘代氟烷与全氟环丙醚生成碘代全氟醚,最后生成2,4-二(ω-碘六氟丙基)-6-七氟丙基-s-三嗪和2,4-二(ω-碘双氧全氟烷基)-6-六氟丙基-s-三嗪,结构式分别为Ⅰ和Ⅱ。利用~(19)F核磁共振谱鉴定其结构。     

含氮杂环润滑添加剂的合成及性能研究

通过摩擦化学中的分子设计思想,设计制备了新型无硫磷含氮杂环润滑添加剂,利用元素分析、傅立叶红外光谱和核磁共振波谱对其结构进行了表征,利用热重试验和油溶性试验考察了其热稳定性及对液体石蜡基础油的感受性,再通过四球试验机、环块试验机、万能摩擦磨损试验机和扫描电子显微镜评价了其在液体石蜡中的摩擦学性能。结果表明:该添加剂具有较好的热稳定性及其对液体石蜡基础油良好的感受性,能明显增加基础油的承载能力、降低长磨磨斑直径和减小摩擦因数,有效提高基础油的摩擦学性能。     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.     

Exploring the scope of the Gewald reaction: Expansion to a four-component process

An efficient four-component reaction was developed to take advantage of the reactivity of the 2-aminothiophene-3-carbonitrile functionality, which is obtained during the classical three-component Gewald reaction. Various α-methylene bearing ketones were reacted with malononitrile, elemental sulfur, and aryl/heteroarylnitrile derivatives in t-BuOH/NaOH to afford 2-arylthieno[2,3-d]pyrimidin-4-amines in high yields. Preliminary studies revealed the photophysical properties of the products and their potential for use as metal sensors.