期刊文献+
共找到633篇文章
< 1 2 32 >
每页显示 20 50 100
不对称Heck反应合成手性哌啶衍生物
1
作者 邵钰 逯飞 刘小宇 《井冈山大学学报(自然科学版)》 2024年第1期23-26,共4页
手性哌啶骨架广泛存在于药物和活性天然产物分子中。本研究发展了一种新型不对称Heck反应,用于合成手性哌啶衍生物。通过对反应条件进行筛选,得到了最优反应条件:催化剂为[Pd(allyl)Cl]_(2)(5 mol%),配体为L5(10 mol%),NaOMe(3.0 equiv... 手性哌啶骨架广泛存在于药物和活性天然产物分子中。本研究发展了一种新型不对称Heck反应,用于合成手性哌啶衍生物。通过对反应条件进行筛选,得到了最优反应条件:催化剂为[Pd(allyl)Cl]_(2)(5 mol%),配体为L5(10 mol%),NaOMe(3.0 equiv)作碱,在110℃的混合溶剂(PhMe/MeOH=5/1)中回流反应20 h。该不对称Heck反应显示出良好的底物普适性,可用于构建多种含有季碳中心的手性哌啶衍生物。 展开更多
关键词 不对称催化 HECK反应 手性哌啶衍生物
下载PDF
顶空气相色谱法同时测定泰地罗新中哌啶和吡啶含量
2
作者 刘葵葵 邢雪敏 +3 位作者 李欣 刘文涛 邓玉晓 刘梦瑶 《精细化工中间体》 CAS 2024年第1期75-78,84,共5页
建立顶空气相色谱法同时测定泰地罗新中哌啶和吡啶的含量。采用Rtx-35 Amine柱(35%联苯-65%二甲基聚硅氧烷为固定液,30 m×0.32 mm,1μm)和氢火焰离子化检测器,程序升温,进样口温度220℃,检测器温度250℃,载气为高纯氮气,流速1.5 mL... 建立顶空气相色谱法同时测定泰地罗新中哌啶和吡啶的含量。采用Rtx-35 Amine柱(35%联苯-65%二甲基聚硅氧烷为固定液,30 m×0.32 mm,1μm)和氢火焰离子化检测器,程序升温,进样口温度220℃,检测器温度250℃,载气为高纯氮气,流速1.5 mL/min,顶空平衡温度90℃,平衡时间30 min。哌啶和吡啶分离度大于2.0,空白溶剂无干扰。吡啶和哌啶在各自浓度范围内线性关系良好(r≥0.9998),检测限分别为0.13、0.12μg/mL,定量限分别为0.41、0.40μg/mL,杂质平均回收率分别为101.7%和102.2%。方法专属性强,灵敏度高,准确度好,满足泰地罗新中哌啶和吡啶含量测定的要求。 展开更多
关键词 顶空气相色谱法 泰地罗新 哌啶 吡啶 含量
下载PDF
2,2’-联吡啶的合成研究
3
作者 王文魁 丁永山 +2 位作者 岳瑞宽 陈洪龙 罗超然 《山东化工》 CAS 2024年第4期55-61,共7页
以吡啶为原料,采用催化剂催化偶联合成2,2’-联吡啶,收率达到81%,探索了温度、压力、反应器、原料等对催化剂寿命及产能的影响。同时,研究了不同条件下,副产物哌啶的生成量,探究了吡啶哌啶分离方法。
关键词 敌草快 联吡啶 哌啶 固定床反应器 负载镍
下载PDF
Syntheses and Characterizations of Two New Organic-inorganic Hybrids Based on Heteropolymolybdates and Piperidine Molecules 被引量:3
4
作者 周端文 张宏 杨振芳 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第3期312-320,共9页
Two new organic-inorganic compounds [(CH2)5NH2]3[PMo12O40]·3[(CH2)NH] 1 and [(CH2)5NH2]6[P2Mo18O62]·5H2O 2 have been synthesized using conventional and hydrothermal methods, respectively, and character... Two new organic-inorganic compounds [(CH2)5NH2]3[PMo12O40]·3[(CH2)NH] 1 and [(CH2)5NH2]6[P2Mo18O62]·5H2O 2 have been synthesized using conventional and hydrothermal methods, respectively, and characterized by elemental analyses, IR, TG and single-crystal X-ray diffraction. X-ray analyses show that in these compounds heteropolymolybdates [PMo12O40]^3- and [P2Mo18O62]^6- are reserved their Keggin or Dawson structures and linked to piperidine through electrostatic and hydrogen-bonding interactions. 展开更多
关键词 organic-inorganic hybrids heteropolymolybdates piperidine molecules
下载PDF
COPOLYMERIZATION OF PROPYLENE WITH HINDERED PIPERIDINE MONOMER OVER A HIGH ACTIVITY SUPPORTED ZIEGLER-NATTA CATALYST 被引量:2
5
作者 杨汉飚 吕起镐 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1997年第2期146-153,共8页
Copolymerization of propylene and hindered piperidine monomers was carried out over a high activity supported Ziegler-Natta catalyst, using Al(C2H5)(3) as cocatalyst. Factors which affect the copolymerization were stu... Copolymerization of propylene and hindered piperidine monomers was carried out over a high activity supported Ziegler-Natta catalyst, using Al(C2H5)(3) as cocatalyst. Factors which affect the copolymerization were studied, The copolymers exhibited high light stability without adding extra light stabilizers. A self-stabilized polypropylene was prepared. 展开更多
关键词 Ziegler-Natta catalyst propylene copolymerization hindered piperidine chemically bound stabilizer self-stabilized polypropylene
下载PDF
New Crystal Structure of Molecular Complex 1-Piperidine Carboxylate-Piperidinium-H_2O Studied by X-Ray Single Crystal Diffraction 被引量:1
6
作者 JIANG Huiming ZHANG Shubiao +1 位作者 JIN Rongchao MA Yunhua 《Wuhan University Journal of Natural Sciences》 CAS 2007年第6期1099-1104,共6页
Piperidine absorbs CO2 and H2O in air to form a molecular complex: piperidium-l-piperidinecarboxylate-H2O. The structure of the complex was characterized by X-ray single crystal diffraction. The crystal structure was... Piperidine absorbs CO2 and H2O in air to form a molecular complex: piperidium-l-piperidinecarboxylate-H2O. The structure of the complex was characterized by X-ray single crystal diffraction. The crystal structure was determined to be triclinic, space group P1^-with a=0.648 6(8) nm, b=0.809 200) nm, c= 1.357 1(16) nm, a=96.96706)°, β =102.506(15)°,γ=104.202 05)°, Z=2. The complex is stabilized via five hydrogen bonds between the three components, N-O electrostatic interaction and O-O interaction (electron transfer) betweenl-piperidinecarboxylate and H2O. Due to electron transference of carbamate ion, the oxygen atom in water molecule is strongly negatively charged and the O-H bond is considerably shorter than that of the free molecule of water. The formation of the molecular complex is a reversible process and will decompose upon heating. The mechanism of formation and stabilization is further investigated herein. 展开更多
关键词 piperidine molecular complex hydrogen bond electron transfer single crystal
下载PDF
Synthesis,Crystal Structure and Bioactivity of N-Phenethyl-4-hydroxy-4-phenyl Piperidine Hydrochloride 被引量:1
7
作者 王海峰 薛思佳 +3 位作者 祝俊 杨定荣 金甲 方治坤 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第6期742-746,共5页
A novel compound N-phenethyl-4-hydroxy-4-phenyl piperidine hydrochloride (C19H24ClNO·H2O) has been synthesized and structurally characterized by elemental analysis, IR, ^1H NMR spectra and single-crystal X-ray ... A novel compound N-phenethyl-4-hydroxy-4-phenyl piperidine hydrochloride (C19H24ClNO·H2O) has been synthesized and structurally characterized by elemental analysis, IR, ^1H NMR spectra and single-crystal X-ray diffraction. The crystal belongs to orthorhombic, space group P212121 with a = 8.6306(8), b = 11.0464(10), c = 19.3221(18)A^°, V = 1842.1(3)A^°^3, Z = 4, Dc =1.211 g/cm^3,μ = 0.217 mm^-1, Mr= 335.86, F(000) = 720, S = 0.973, R = 0.0420 and wR = 0.1009 for 3627 unique reflections with 3157 observed ones (I 〉 2σ(I)). In the crystal, the dihedral angles made by piperidine ring with two benzene rings are 84.8(6) and 62.5(7)°, respectively. Intermolecular O-H…O and O-H…Cl hydrogen bonds involving water molecules form chains along the b axis, which stabilizes the crystal structure. The preliminary bioactivity tests indicated that the title compound has good effect of cellular growth inhibition to K562 cells and potential bioactivity of anti-leukemia. 展开更多
关键词 crystal structure piperidine derivatives SYNTHESIS bioactivity
下载PDF
Study of the distribution profile of piperidine alkaloids in various parts of Prosopis juliflora by the application of Direct Analysis in Real Time Mass Spectrometry(DART-MS) 被引量:1
8
作者 Shachi SINGH Sanjay Kumar VERMA 《Natural Products and Bioprospecting》 CAS 2012年第5期206-209,共4页
Direct Analysis in Real Time Mass Spectrometry(DART-MS)was applied to identify and study the distribution profile of piperidine alkaloids in different parts of Prosopis juliflora,without isolation and separation of th... Direct Analysis in Real Time Mass Spectrometry(DART-MS)was applied to identify and study the distribution profile of piperidine alkaloids in different parts of Prosopis juliflora,without isolation and separation of the compounds by standard chromatographic techniques.With the help of DART-MS,chemical fingerprint of raw plant parts were generated,which revealed the presence of piperidine alkaloids in leaf,pod and flower.A comparative study of the distribution pattern,showed variation in the presence and distribution of these alkaloids in various parts of P.juliflora.The leaves and pod displayed the largest alkaloid pattern with a total of 12 different alkaloids in each part,whereas only 4 alkaloids were present in flower.Alkaloids:julifloridine,prosopine,prosopinine and prosafrinine were ubiquitously distributed in all the alkaloid rich plant parts.Juliprosopine was pre-eminet alkaloid in leaf,whereas pod and flower displayed copious amounts of julifloridine. 展开更多
关键词 DART-MS chemical fingerprint Prosopis juliflora piperidine alkaloids juliprosopine julifloridine
下载PDF
NMR and FT-IR Analysis of New Molecular Complex 1-Piperidine-carboxylate-Piperidinium-H_2O
9
作者 JIANG Huiming ZHANG Shubiao JIN Rongchao 《Wuhan University Journal of Natural Sciences》 CAS 2008年第1期93-97,共5页
Piperidine absorbs CO2 and H2O contents in air to form a molecular complex: piperidium-1-piperidinecarboxylate-H2O. The structure of the complex was characterized by FT-IR and NMR. The complex is stabilized via five ... Piperidine absorbs CO2 and H2O contents in air to form a molecular complex: piperidium-1-piperidinecarboxylate-H2O. The structure of the complex was characterized by FT-IR and NMR. The complex is stabilized via five hydrogen bonds between the three components, N…O electrostatic interaction and O…O interaction (electron transfer) betweenl-piperidinecarboxylate and H2O. Through electron transfer from the carbamate ion, the oxygen atom in water molecule is strongly negatively charged and the O-H bond is considerably shorter than that of free water molecule. The formation of the molecular complex is a reversible process and will decompose upon heating. The mechanism of formation and stabilization is further investigated herein. 展开更多
关键词 piperidine molecular complex NMR FT-IR hydrogen bond electron transfer
下载PDF
SYNTHESIS AND LIGHTFASTNESS PROPERTIES OF DYES CONTAINING HINDERED PIPERIDINE RESIDUES AS INTERNAL STABILIZING GROUPS
10
作者 戴瑾瑾 John Griffiths 《Journal of China Textile University(English Edition)》 EI CAS 1991年第4期24-33,共10页
The representative azo and anthraquinone dyes containing an insulated hindered piperidinegroup were synthesized.The effect of these pendent groups on lightfastness properties of the dyeswas studied,both in ethyl aceta... The representative azo and anthraquinone dyes containing an insulated hindered piperidinegroup were synthesized.The effect of these pendent groups on lightfastness properties of the dyeswas studied,both in ethyl acetate solution and on cellulose acetate and polyester films.The differ-ent trend of fading rates of azo dyes and anthraquinone dyes in solution and on substrates suggestsdifferent fading mechanisms operating in each case. 展开更多
关键词 LIGHTFASTNESS SYNTHESIS DYES hindered piperidine group intra-molecular stabilized DYE
下载PDF
Organic-inorganic Hybrid Materials Based on Piperidine Derivatives and Semi-conductive Metal Iodine
11
作者 裴亮昌 魏振宏 +2 位作者 张秀秀 尧娇娇 蔡琥 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2019年第9期1494-1502,共9页
Reactions of piperidine derivatives 4-(aminomethyl)piperidine(4-AMPD) and 1-methylpiperidin-4-amine(1-MPDA) with semi-conductive metal iodine SbI3 and PbI2 in concentrated HI aqueous solution afforded two one-dimensio... Reactions of piperidine derivatives 4-(aminomethyl)piperidine(4-AMPD) and 1-methylpiperidin-4-amine(1-MPDA) with semi-conductive metal iodine SbI3 and PbI2 in concentrated HI aqueous solution afforded two one-dimensional(1 D) chain compounds [(4-AMPD)SbI5]n(1), [(1-MPDA)SbI5]n(2) and a two-dimensional(2 D) single layered organicinorganic hybrid material [(1-MPDA)PbI4]n(3), which were confirmed by X-ray single-crystal diffraction, infrared(IR) spectroscopy and powder X-ray diffraction(PXRD). Simultaneously, compounds 1~3 exhibit strong emission peaks at 600 nm for 1 and 2 and 570 nm for 3, which were originated from their inorganic moieties. 展开更多
关键词 ORGANIC-INORGANIC hybrid piperidine DERIVATIVES semi-conductive METAL IODINE FLUORESCENT property
下载PDF
Asymmetric Syntheses of Pharmaceutically Interesting Piperidines
12
作者 LIU Liang-Xian Wei Bang-Guo HUANG Pei-Qiang 《合成化学》 CAS CSCD 2004年第z1期23-23,共1页
关键词 CHIRAL Synthon piperidine (+)-L-733 060 (+)-CP-99 994 febrifugine isofebrifugine
下载PDF
Mechanistic Study on the Monofunctional Binding of Hydrolysis Products of Non-planar Heterocyclic Complexes Trans-[PtCl_2NH_3(piperidine)] and Trans-[PtCl_2(piperidine)_2] to DNA Purine Bases
13
作者 陈鋆晖 周立新 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第10期1536-1546,共11页
The monofunctional substitution reactions between trans-[PtCl(H2O)(NH3)(pip)]+,trans-[Pt(H2O)2(NH3)(pip)]2+,trans-[PtCl(H2O)(pip)2]+,trans-[Pt(H2O)2(pip)2]2+ (pip = piperidine) and adenine/gu... The monofunctional substitution reactions between trans-[PtCl(H2O)(NH3)(pip)]+,trans-[Pt(H2O)2(NH3)(pip)]2+,trans-[PtCl(H2O)(pip)2]+,trans-[Pt(H2O)2(pip)2]2+ (pip = piperidine) and adenine/guanine nucleotides are explored by using B3LYP hybrid functional and IEF-PCM salvation models. For the trans-[Pt(H2O)2(NH3)(pip)]2+ and trans-[PtCl(H2O)(NH3)(pip)]+ complexes,the computed barrier heights in aqueous solution are 13.5/13.5 and 11.6/11.6 kcal/mol from trans-Pt-chloroaqua complex to trans/cis-monoadduct for adenine and guanine,and the corresponding values are 20.7/20.7 and 18.8/18.8 kcal/mol from trans-Pt-diaqua complex to trans/cis-monoadduct for adenine and guanine,respectively. For trans-[PtCl(H2O)(pip)2]+ and trans-[Pt(H2O)2(pip)2]2+,the corresponding values are 21.5/21.3 and 19.4/19.4 kcal/mol,and 26.0/26.0 and 20.7/20.8 kal/mol for adenine and guanine,respectively. Our calculations demonstrate that the barrier heights of chloroaqua are lower than the corresponding values of diaqua for adenine and guanine. In addition,the free energies of activation for guanine in aqueous solution are all smaller than that for adenine,which predicts a preference of 1.9 kcal/mol when trans-[PtCl(H2O)(NH3)(pip)]+ and trans-[Pt(H2O)2(NH3)(pip)]2+ are the active agents and ~1.9 and ~ 5.3 kcal/mol when trans-[PtCl(H2O)(pip)2]+ and trans-[Pt(H2O)2(pip)2]2+ are the active agents,respectively. For the reaction of trans-Pt-chloroaqua (or diaqua) to cis-monoadduct,we obtain the same transition-state structure as from the reaction of trans-Pt-chloroaqua (or diaqua) to trans-monoadduct,which seems that the trans-Pt-chloroaqua (or diaqua) complex can generate trans-or cis-monoadduct via the same transition-state. 展开更多
关键词 DFT trans-[PtCl2NH3(piperidine)] and trans-[PtCl2(piperidine)2] DNA bases transition state activation energy
下载PDF
Design,synthesis and biological estimation of 1-(benzoxazole-2-yl)piperazine and 4-(benzoxazole-2-yl)piperidine derivatives as potentialα_1-AR antagonists 被引量:1
14
作者 Jia Bin Li Lin Xia +2 位作者 Bin Wu Tao Wang Zhen Zhou Jiang 《Chinese Chemical Letters》 SCIE CAS CSCD 2008年第10期1193-1195,共3页
1-(benzoxazole-2-yl ) 的二个系列 piperazine (哌啶加重的 8a 鈥搃) 和 4-(benzoxazole-2-yl )(10a 鈥搃) 被设计,综合并且为他们的伪 1 评估了 -AR 对抗活动。在 vitro 的生物试金显示 10h 显示出稍微更强壮的伪 1 -AR 对抗活动到... 1-(benzoxazole-2-yl ) 的二个系列 piperazine (哌啶加重的 8a 鈥搃) 和 4-(benzoxazole-2-yl )(10a 鈥搃) 被设计,综合并且为他们的伪 1 评估了 -AR 对抗活动。在 vitro 的生物试金显示 10h 显示出稍微更强壮的伪 1 -AR 对抗活动到我们的铅混合物的 1。 展开更多
关键词 BPH α1-AR 苯并 哌啶 拮抗物 哌嗪
下载PDF
Anodic Cyanation of 1-(1-Methoxycarbonyl ethyl) piperidine
15
作者 PingZHAO YingWuYIN 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第9期1043-1046,共4页
Aminonitriles were prepared efficiently from anodic cyanation of ?amino ester. The effect of different solvents and electrolytes was studied. The other byproducts were analyzed.
关键词 Aminonitriles 1-(1-methoxycarbonylethyl) piperidine anodic cyanation electrolysis.
下载PDF
新型哌啶-4-醇衍生物的合成及生物活性
16
作者 孙海洋 杨晓宁 +2 位作者 李晖 王佳毅 宋恭华 《农药学学报》 CAS CSCD 北大核心 2023年第2期329-339,共11页
发现具有新作用方式的农药对于现代作物保护至关重要。本研究以哌啶醇和邻苯二酚为起始原料,经5步反应制备得到了一系列新型的哌啶-4-醇衍生物,并通过核磁共振氢谱、碳谱和高分辨质谱确认其结构。生物活性测试结果表明,部分目标化合物在... 发现具有新作用方式的农药对于现代作物保护至关重要。本研究以哌啶醇和邻苯二酚为起始原料,经5步反应制备得到了一系列新型的哌啶-4-醇衍生物,并通过核磁共振氢谱、碳谱和高分辨质谱确认其结构。生物活性测试结果表明,部分目标化合物在25 mg/L质量浓度下表现出良好的根结线虫Meloidogyne incognita抑制活性。此外,在500 mg/L质量浓度下,大部分化合物对黏虫Pseudaletia separata Walker表现出因拒食效应所致的体重减轻。 展开更多
关键词 哌啶-4-醇 杀线虫活性 黏虫 拒食效应
下载PDF
通过TEMPO增强脱氢和OH吸附促进中性电解质中5-羟甲基糠醛的电催化氧化
17
作者 王洪芳 徐雷涛 +6 位作者 吴景程 周鹏 陶沙沙 逯宇轩 吴贤文 王双印 邹雨芹 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第3期148-156,共9页
生物质衍生物的电催化转化为可持续能源的增值利用提供了一条绿色高效的途径.例如,由5-羟甲基糠醛(HMF)氧化可得到生物基聚酯前驱体2,5-呋喃二甲酸(FDCA),对于缓解化石资源带来的能源危机和环境问题具有重要意义.目前,HMF的电催化氧化... 生物质衍生物的电催化转化为可持续能源的增值利用提供了一条绿色高效的途径.例如,由5-羟甲基糠醛(HMF)氧化可得到生物基聚酯前驱体2,5-呋喃二甲酸(FDCA),对于缓解化石资源带来的能源危机和环境问题具有重要意义.目前,HMF的电催化氧化通常在强碱性(pH>13.5)溶液中进行,但是容易产生难以分离的腐殖质,影响FDCA的工业利用.另外,强碱性介质还存在腐蚀安全隐患、设备维护成本高等问题.中性反应条件有助于改善上述问题,但是缺乏亲电氧物种(例如OH-),HMF和催化剂的活化困难,难以得到高附加值产物FDCA.目前,针对中性介质中HMF的电催化氧化研究少有报道,急需明晰中性介质中HMF的催化机理,并开发中性条件下具有高活性的催化剂体系.本文利用均相催化剂2,2,6,6-四甲基哌啶-1-氧基(TEMPO)和Co_(3)O_(4)电极,对HMF进行中性条件下电催化氧化,1.55 VRHE条件下反应1.5 h,以接近100%转化率获得产物FDCA,产率大于99%.而在无TEMPO的条件下,HMF在Co_(3)O_(4)电极上转化率小于2%.原位红外等实验测试及理论计算结果表明,低电位(1.10 VRHE)下形成的TEMPO+阳离子的活化能显著减低HMF,通过脱氢作用选择性生成中间产物2,5-二甲酰基呋喃(DFF),对调控HMF的氧化路径、促进中性介质电催化氧化起到关键作用.原位X射线光电子能谱和电化学阻抗等结果发现,TEMPO存在时,1.35 V后,在含有高价态Co^(3+)/^(4+)的Co_(3)O_(4)电极上出现更多的水以及OH吸附物种,并导致HMF的氧化电流密度以及FDCA的转化率显著增加.理论计算结果表明,TEMPO自由基与水分子存在较强的氢键作用,有利于促进水活化提供OH.然而,低电位(1.25 V)以Co_(3)O_(4)为电极,或高电位(1.55 V)以泡沫镍为电极,即使添加TEMPO,电极上没有出现相应的OH吸附行为和电化学活性提升现象.因此,活性的Co_(3)O_(4)电极对于协同水的解离形成OH具有重要作用,二者共同作用下,水活化解离形成Co^(3+)/^(4+)-(OH)_(ads)活性中心.在中性溶液中,亲电氧物种OHads提供氧源,促进DFF等甲酰基中间体进一步氧化转化为FDCA.综上,本文加深了对中性介质中HMF的电催化氧化机制的理解,对设计类似电催化剂体系有借鉴作用. 展开更多
关键词 5-羟甲基糠醛 电催化氧化 2 2 6 6-四甲基哌啶-1-氧基 中性电解 中性电解质 生物质电催化
下载PDF
(4-羟基-3-甲氧基苯基)(2-甲基哌啶-1-基)甲酮的合成
18
作者 于芳蕾 吉彦彬 +1 位作者 徐小娜 张娟 《化学工程师》 CAS 2023年第6期9-13,共5页
本文报道了(4-羟基-3-甲氧基苯基)(2-甲基哌啶-1-基)甲酮(1a)的合成。以4-羟基-3-甲氧基苯甲酸(2)和2-甲基哌啶(3)为原料,经缩合反应得到目标化合物(1a)。并考察该反应工艺,确定适宜的反应条件为:物料比为n(3)∶n(2)=1.8∶1、反应溶剂为... 本文报道了(4-羟基-3-甲氧基苯基)(2-甲基哌啶-1-基)甲酮(1a)的合成。以4-羟基-3-甲氧基苯甲酸(2)和2-甲基哌啶(3)为原料,经缩合反应得到目标化合物(1a)。并考察该反应工艺,确定适宜的反应条件为:物料比为n(3)∶n(2)=1.8∶1、反应溶剂为N,N-二甲基甲酰胺、反应温度为40℃、反应时间为2h。在该条件下,产物(1a)收率达到88.6%。对该反应工艺的拓展应用发现,该条件同样适用于4-羟基-N,3-二甲氧基-N-甲基苯甲酰胺(1b)的合成,收率达到90.3%。产物结构经过^(1)H NMR和^(13)C NMR表征确证。 展开更多
关键词 哌啶衍生物 Weinreb酰胺 缩合反应 合成
下载PDF
Continuous microflow visible-light photocatalytic N-formylation of piperidine and its kinetic study
19
作者 Yangyang Xu Fang Zhao Xuhong Guo 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第1期285-289,共5页
N-formylation of amines,a class of synthetically important reactions,is typically conducted using metal catalysts that are relatively expensive or not readily available and usually needs harsh conditions to increase t... N-formylation of amines,a class of synthetically important reactions,is typically conducted using metal catalysts that are relatively expensive or not readily available and usually needs harsh conditions to increase the reaction efficiency.Here,an efficient continuous microflow strategy was developed for the gas-liquid visible-light photocatalytic N-formylation of piperidine,which achieved a reaction yield of 82.97%and a selectivity of>99%at 12 min using cheap organic dye photocatalyst under mild reaction conditions.The influence of essential parameters,including light intensity,temperature and equivalents of the gas,additive and photocatalyst,on the reaction yield was systematically studied.Furthermore,kinetic investigations were conducted,exhibiting the dependence of reaction rate and equilibrium yield of N-formylpiperidine on light intensity,temperature and photocatalyst equivalent.The microflow photocatalytic approach established in this work,which realized a markedly higher space-time yield than the conventional batch method(37.9 vs.0.212 mmol h-1 L-1),paves the way for the continuous,green and efficient synthesis of N-formamides. 展开更多
关键词 MICROFLOW Visible-light photocatalysis N-FORMYLATION piperidine KINETICS
原文传递
手性哌啶并咪唑啉二酮类化合物的除草活性研究 被引量:1
20
作者 张帆 刘克 +2 位作者 杨辉斌 崔东亮 李斌 《世界农药》 CAS 2023年第3期43-48,共6页
以2-(2-氟-4-氯-5-炔丙氧基苯基)-四氢咪唑并[1,5-a]吡啶-1,3(2H,5H)-二酮(a)为先导化合物,对苯环1-位N杂环手性以及5-位取代基进行变化,合成了12个手性哌啶并咪唑啉二酮类化合物,测试了其对百日草和苘麻生长的抑制率,并对其构效关系进... 以2-(2-氟-4-氯-5-炔丙氧基苯基)-四氢咪唑并[1,5-a]吡啶-1,3(2H,5H)-二酮(a)为先导化合物,对苯环1-位N杂环手性以及5-位取代基进行变化,合成了12个手性哌啶并咪唑啉二酮类化合物,测试了其对百日草和苘麻生长的抑制率,并对其构效关系进行了研究。结果表明(R)-2-(4-氯-2-氟-5-炔丙氧基苯基)四氢咪唑[1,5-a]吡啶-1,3(2H,5H)-二酮(R-1)对百日草活性较好,(S)-2-(4-氯-2-氟-5-炔丙氧基苯基)四氢咪唑[1,5-a]吡啶-1,3(2H,5H)-二酮(S-1)对苘麻活性较好,与先导化合物a相当,为发现高除草活性PPO抑制剂提供指导。 展开更多
关键词 哌啶并咪唑啉二酮 手性 构效关系 除草活性 PPO抑制剂
下载PDF
上一页 1 2 32 下一页 到第
使用帮助 返回顶部