Synthesis of Enamines via the Cross-coupling of Thioamides and Diarylketones Promoted by the Sm/SmI_(2)Mixed Reagent

Enamines, promoted by the samarium/samarium diiodide mixed reagent, were synthesized via the cross-coupling of thioamides and diarylketones in good yields.

Synthesis Characterization and Biological Activities of an Enamine Derivative and Its Coordination Compounds

The medicinal uses and applications of metal complexes are of increasing clinical and commercial importance;this is as a result of some level of success achieved so far. In this regard, novel enamine free-base ligands were synthesized by the condensation of terephthalaldehyde and 2-(methylamino)ethanol. This afforded a dinegative ONNO donor enamine, free base, characterized using 1H and 13C NMR, Fourier-transformed infrared and UV-vis spectroscopy. Coordination compounds of the enamine were also synthesized using Cu(II), Ni(II), Co(II) and VO(IV) ions. These complexes were characterized by electronic, IR spectrophotometry, mass spectrometry, magnetic susceptibility and EDX. The compounds were thereafter evaluated for their antimicrobial and cytotoxic activities. The data obtained were supportive of an octahedral geometry for the Cu(II) complex, a square-pyramidal geometry for the vanadium complex and a 4-coordinate square-planar geometry for both the cobalt and nickel complexes. The magnetic susceptibility data revealed that the complexes are magnetically dilute and mononuclear with exception of the cobalt complex. The ligands and the complexes did not exhibit significant antimicrobial and cytotoxic assays, indicative of the nontoxicity of the ligand and complexes.

Relative Stability of the Key Enamine,Oxazolidinone,and Imine Intermediates in Some Proline-catalyzed Asymmetric Reactions

Many proline-catalyzed asymmetric addition reactions with ketones as substrates were assumed to involve a key intermediate, an enamine, produced by the condensation of proline and ketone. In this paper, the key intermediate enamines derived from L-proline and cyclohexanone （or acetone） as well as the corresponding oxazolidinone and imine tautomers have been investigated by means of density functional calculations at the B3LYP/6-311＋G^＊＊ level. The predicted order of stability for these tautomers is oxazolidinones 〉 enamines 〉 imines in gas phase and oxazolidinones 〉 imines 〉 enamines in aprotic THF solvent. This prediction explains why enamine intermediate can not be observed experimentally. The predicted energy/enthalpy difference between the formal oxazolidinone structure and the zwitterionic imine structures is very small in THF solvent, suggesting the oxazolidinone-to-imine tautomerization can be readily induced in solvent. ^13C NMR chemical shifts of the oxazolidinone and imine structures have been computed and used to explain the experimental NMR spectra observed in oxazolidinone-to-imine tautomerization induced by protic solvent.

Enamine Configuration of 5-Methyl-2-phenyl-4- [(Z)-3-tolylamino-phenylmethylene]pyrazol-3(2H)-one

Compound 5-methyl-2-phenyl-4-[（Z）-3-tolylamino-phenylmethylene]pyrazol-3（2H）-one （C24H21N3O） crystallizes in the triclinic system, space group P1, with a = 9.267（3）, b = 9.904（4）,c = 12.035（4） A°, α = 97.896（6）, β = 103.865（6）, γ = 107.950（6）°, Mr= 367.44, Z = 2, V = 993.2（6）A°^3,Dc = 1.229 g/cm^3,μ（MoKa） = 0.077 mm^-1 and F（000） = 388. The structure was refined to R =0.0444 and wR = 0.1199 for 2903 observed reflections （I 〉 2σ（I））. The results of ^1H NMR and single-crystal X-ray diffraction studies showed the enamine character of the compound. The strong intramolecular hydrogen bonds in the large conjugate system, together with weak intermolecular C-H……π hydrogen bonding and π……π stacking, lead to the formation of a multi-dimensional supramolecular network.

Solvent-controlled stereodivergent synthesis of E-and Z-enamines via metal-free formal C(sp2)-H amination ofα-substituted styrenes

C(sp2)-H amination represents an attractive approach for the synthesis of enamines,which is intrinsically associated with the challenge of controlling of stereochemistry and primarily relying on transition-metal catalysis.Herein,a metal-free C(sp2)-H amination ofα-substituted styrenes has been achieved,leading to stereodivergent formation of both E-and Z-enamines in 50%–97%yield under mild conditions by using PhI(OAc)2 as a green oxidant and ortho-phenylenediamines as nitrogen source.Interestingly,the Z/E selectivity can be controlled readily by switching the reaction medium.E-isomers were formed preferentially in THF,whereas n-hexane favored the formation of Z-isomers.Preliminary mechanistic studies suggested that in situ formed ortho-benzoquinone diimides are the key intermediates,and there is a correlation between solvent polarity and stereoselectivity.This study enriches the chemical repertoire of ortho-benzoquinone diimides particularly with respect to sustainable amination.

烯胺溶液吸收和解吸模拟烟气中二氧化碳实验研究

采用搅拌实验装置对二乙烯三胺(DETA)、三乙烯四胺(TETA)、三乙烯二胺(TEDA)溶液吸收和解吸模拟烟道气中二氧化碳特性进行研究,揭示了吸收速率、吸收容量和解吸速率与酸碱度、时间之间的内在联系,并与一乙醇胺(MEA)、二乙醇胺(DEA)溶液进行了对比分析。实验表明,同浓度DETA、TETA吸收速率及吸收容量均高于MEA和DEA,再生简单,是优良的烟道气CO2吸收剂,具有较高的研究价值。

有机钼酸盐MDTA对碳钢的缓蚀作用和机理

对合成的有机烯胺钼酸盐缓蚀剂,采用多种方法研究了其对Q235钢的缓蚀作用和机理,确定了其临界保护浓度,发现MDYA对碳钢有良好的缓蚀效果,分子内的有机基团和无机基团间有明显协同缓蚀作用,主要抑制腐蚀的阳极过程;在碳钢表面的成膜过程中,部分MoO_4^(2-)被还原成MoO_2,膜的成分主要为Fe_2(MoO_4)_3、FeMoO_4以及烯胺DTA和MDTA与Fe的螫合物.

烯胺在乙醇溶液中吸收CO2的研究

将沼气中CO_2脱除后可以作为天然气替代品,化学吸收法缺点是再生能耗较高,实验中发现烯胺类物质在乙醇中吸收CO_2后会产生相分离现象,这可以降低再生过程的能耗,故研究了温度与浓度对三乙烯四胺(TETA)乙醇溶液吸收CO_2的吸收速率与单分子吸收负荷的影响,并采用二乙烯三胺(DETA)、三乙烯四胺(TETA)以及四乙烯五胺(TEPA)的乙醇溶液在相同条件下吸收模拟沼气中CO_2,考察吸收速率、吸收量及单氨基吸收负荷随时间的变化关系。实验结果显示,在TETA乙醇溶液中,随着TETA浓度从0.1 kmol×m^(-3)增加至0.3 kmol×m^(-3),总吸收量增大,而TETA单分子吸收负荷从1.88 mol CO_2×mol amine^(-1)降至1.59 mol CO_2×mol amine^(-1),TETA乙醇溶液吸收CO_2产生的固体经过DSC表征发现在363 K开始分解;从DETA,TETA至TEPA,烯胺分子中氨基数量随之增多,CO_2吸收速率与单分子吸收负荷也随之增加,而烯胺分子中单个氨基吸收负荷却随之减小,其中TEPA有着最大的CO_2单分子吸收负荷(2.11 mol CO_2×mol amine^(-1)),DETA有着最高的分子中单个氨基吸收负荷(0.48 mol CO_2×mol amine group-1)。

水相介质中碳酸钾/硫脲联合促进邻位氨基溴转变成α,β-脱氢氨的研究

建立了在水相介质中,在碳酸钾/硫脲联合促进下,具有邻位氨基溴的酯和邻位氨基溴的酮在室温下发生溴化氢消除反应,高收率地制备α,β-脱氢氨(功能化烯胺)的新方法.共考察了23种不同结构α,β-邻位氨基溴的酯和α,β-邻位氨基溴的酮的反应情况,证明该方法具有广泛的适应性.实验发现,无论底物为α-氨基-β-溴结构还是α-溴-β-氨基结构,反应过程中都要经过一个氮丙啶过程,而氮丙啶的开环是区域专一的,因此产物具有区域专一性(烯键上的氨基均处在羰基的α-位).所有产物的结构均经过核磁共振波谱及高分辩率质谱确证.克量级放大实验结果表明,该方法具有一定的用于工业化生产的可行性.

功能化烯胺的合成(Ⅳ):醋酸钠快速促进β,β-二氰基苯乙烯衍生物与NBS反应转变成相应的烯胺

建立了由缺电子烯烃(β,β-二氰基苯乙烯衍生物)与N-溴代丁二酰亚胺(NBS)反应快速转变成功能化烯胺的新方法.缺电子烯烃在N,N-二甲基酰胺(DMF)溶剂中,在NaOAc促进下与NBS反应,可快速转变成相应的烯胺.在优化的条件下,考察了12种β,β-二氰基苯乙烯衍生物与NBS的反应情况,各种β,β-二氰基苯乙烯衍生物均能转变成相应的烯胺,证明该方法具有广泛的适应性.该方法操作简单,反应条件温和,反应收率高(最高收率可达98%).所用催化剂易得、稳定,价格低廉,并且反应具有高度的区域选择性,为合成功能化烯胺提供了一个有效途径.所有产物结构均经过核磁共振波谱和高分辨率质谱确证.

消旋棉酚拆分的研究——Ⅲ.胺缩棉酚理化性质的研究

本文报道消旋棉酚与15种不同结构的光学活性胺缩合产物的薄层色谱性质和核磁共振氢谱数据,以及8个光学活性胺与光学活性棉酚缩合物的光学稳定性,并探讨了结构与这些性质的关系。

烯胺活化羟乙基乙二胺吸收CO_2的反应热

以羟乙基乙二胺(AEEA)为基础吸收剂,分别加入二乙烯三胺(DETA)、三乙烯四胺(TETA)、四乙烯五胺(TEPA)作为活化剂,探讨了不同烯胺体积分数和CO_2负载量(吸收的CO_2与活化吸收剂的摩尔比)对各烯胺活化的AEEA吸收剂CO_2吸收热、解吸热、CO_2脱除率的影响。综合对比结果,最优的活化吸收剂为AEEA+5%(φ)DETA,其最低CO_2吸收热为63.0 k J/mol(以每摩尔CO_2计),解吸热为82.5 k J/mol,CO_2脱除率为76.2%。

N-烷基取代烯胺合成方法研究

本文研究了一种通用的N-烷基取代烯胺合成方法。着重探讨了反应物配比、催化剂用量、反应时间等条件对缩合反应的影响。在优化的工艺条件下,能获得纯度较好,收率较高的N-烷基取代烯胺。

液晶中间体4-烷基环己酮的新合成方法研究

报道了液晶中间体４－烷基环己酮（Ｃ３～Ｃ７）的合成新方法及实验结果。它以醛为基本原料，制成烯胺后，与丁烯酮加成、缩合、加氢而得。方法简便，周期短，产率高。

2－芳基丙酸类消炎镇痛药物的研究5 羟醛缩合法合成酮基布洛芬

以环己酮为起始原料，经Ｓｔｏｒｋ烯胺反应、羟醛缩合、消除、芳构化制得酮基布洛芬，总收率４３．２％。

长春西汀中间体-1-(2',2'-二羧乙酯乙基)-1-乙基-1,2,3,4,6,7,12,12b-八氢吲哚(2,3-a)喹嗪的合成

提出了一条以Wenkert's烯胺和二甲羧乙酯基乙烯为原料合成长春西汀的关键中间体-1-(2',2'-二羧乙酯乙基)-1-乙基-1,2,3,4,6,7,12,12b-八氢吲(2,3-a)喹嗪的新路线。对新工艺条件进行了优化,反应温度85℃,反应时间7h、催化剂用量5.1%,此优化条件下中间体收率达到85.5%。利用红外光谱、质谱和核磁共振确定了中间体的结构。

甲氧基香茅醛合成工艺研究

以香茅醛为原料，经二甲胺羰基保护、硫酸催化条件下甲氧基化、氢氧化钠中和合成甲氧基香茅醛。考察了反应温度、反应时间、投料比等工艺条件对产品收率的影响。实验研究得到了最优的合成工艺条件为：胺化反应二甲胺与香茅醛摩尔比为2：1，反应温度10～15℃，反应时间3h。甲氧基化反应硫酸浓度为100％，甲醇；硫酸：烯胺的摩尔比为15：5：1，反应温度15～18℃，反应时间2h。产品总收率47．6％。反应工艺简单，条件温和，原料易得，便于工业化。产品经IR、^1H NMR、GC／MS、元素分析确证结构。

硒粉催化合成N-乙烯基双苯磺酰胺类化合物

烯胺有广泛的应用价值,烯烃和胺反应合成烯胺的方法存在重金属残留或不能循环催化的局限性。以硒粉为催化剂,以取代苯乙烯和N-氟代双苯磺酰胺为原料,通过研究催化剂、溶剂、温度、添加物对产物N-(苯磺酰)-N-(1-(对甲苯基)乙烯基)苯磺酰胺产率的影响,得到最佳反应条件:10 mol%硒粉为催化剂,空气气氛中,在V(对二甲苯)∶V(氯苯)=1∶1的混合溶剂中80℃反应,用三乙基铵苯磺酰亚胺[Et_(3)NH][N(SO_(2)Ph)_(2)]为添加物。硒粉可循环催化对甲苯乙烯和N-氟代双苯磺酰胺的氧化胺化反应。对烯烃底物进行拓展,得到5种目标产物,并通过^(1)HNMR、^(13)CNMR和HRMS对产物的结构进行表征。