手性镧系位移试剂核磁共振法测定芳氧丙酸酯类除草剂对映体纯度

以Eu(hfc)3和Pr(hfc)3为手性镧系位移试剂(CLSR),比较了两种CLSR对2,4-滴丙酸甲酯的1HNMR和13C NMR谱手性分离效果,结果表明:Pr(hfc)3比Eu(hfc)3对手性中心相连的甲基具有更好的手性分离效果。首次应用Pr(hfc)3测定了盖草能、稳杀得和喹禾灵3种手性芳氧丙酸酯类除草剂的1HNMR和13CNMR谱,其1HNMR谱分离度R约为1,盖草能和喹禾灵的13C NMR谱分离度R大于1.5,说明1H NMR和13CNMR谱手性分离效果适用于对映体纯度测定。与手性色谱法相比,CLSR-NMR法测定对映体纯度具有操作简便、分析速度快的显著优势。     

核磁共振法研究固体表面上的吸附

应用JEOL FX-90Q NMR谱仪测定了吸附在NaY分子筛,氧化铝,二氧化硅上的四甲基硅烷和正己烷的核磁氢谱和碳谱.结果表明,在一些吸附体系的研究中,现有仪器适用于液体样品,以氢谱和碳谱比较发现碳谱在分辨率分方面较之氢谱有几个优点,顺磁杂质对谱线宽度有明显影响.在NaY分子筛上预先吸附氢以后再吸附乙烯,其吸附速率低于未吸附氢的样品.     

1,2-H(XPhCH2)C60衍生物中取代基团对NMR及电化学性质的影响

为了考察取代基团对C60衍生物性质的影响,分别进行了一系列1,2-H(XPhCH2)C60(X=H,o-CH3,m-CH3,p-CH3,o-Br,m-Br,p-Br)的1H NMR、13C NMR和电化学循环伏安测试。 结果表明,邻位取代基团对苄基中亚甲基氢原子和碳原子的核磁响应具有较大的影响,而取代基团位置对C60-H和C60sp3碳原子核磁响应影响较小;在循环伏安中,苄基上的-CH3和-Br基团位置对C60衍生物的氧化还原电势并未表现出显著影响,但与1,2-H(PhCH2)C60相比,所有具有CH3PhCH2-基团的化合物氧化还原电势均表现出负移,而具有BrPhCH2-基团的化合物氧化还原电势均表现出正移,表明诱导效应是影响C60衍生物性质的主要因素,因此,可通过调控衍生物的电子结构来探究其性质。     

Derivatization of fullerene dimer C120 by the Bingel reaction and a 3He NMR study of 3He@C120 monoadducts.

Cyclopropanation with diethyl bromomalonate and base (the Bingel reaction) was conducted on fullerene dimer C120 to give a mixture of "monoadducts" (45% yield) and "bisadducts" (< or =37% yield), while 18% of the C120 remained unchanged. The "monoadducts" were separated into five positional isomers, i.e., e(face), e(edge), trans-4, trans-3, and trans-2, by preparative HPLC. Assignments were made based on 1H (and 13C) NMR and confirmed by theoretical calculations of the addends' 1H NMR chemical shifts. The relative yields of these isomers were in fair agreement with those observed for the Bingel bisaddition of C60. The Bingel reaction was also carried out on the dimer C120 encapsulating 3He in one of the C60 cages. Each positional isomer of the "monoadduct" exhibited a pair of 3He NMR signals corresponding to an isomer with functionalization on the 3He-containing cage and the other isomer with functionalization on the empty cage. Using the 3He NMR spectroscopy, a pair of signals for the trans-1 isomer, which eluded detection by 1H NMR, were observed, in addition to pairs of signals for e(face), e(edge), trans-4, trans-3, and trans-2 isomers. The 3He NMR signals for isomers with functionalization on the 3He-containing cage were spread out over a 1.82-ppm range reflecting the direct effects of the addition pattern on the C60 surface. In contrast, the isomers with functionalization on the empty cage exhibited 3He NMR signals that appeared over a 0.14-ppm range, which was shown to be primarily due to changes in the diamagnetism of the functionalized cage based on theoretical calculations of 3He NMR chemical shifts for the model system in which the C60 cage encapsulating 3He was removed.     

偕双硅2,3-环氧醇区域及立体选择性环氧开环/卤代反应研究

C³-位偕双硅取代的2,3-环氧醇分别与对甲苯磺酰氯、溴素和单质碘发生C³-位区域及立体选择性环氧开环/卤代反应合成了15个新的C³-位卤代偕双硅基1,2-二醇类产物,收率64%~87%,其结构经¹H NMR, ¹³C NMR和HR-MS（ESI）表征。产物的立体结构经3-［二甲基（苯基）甲硅烷基］-3-碘-3-（三甲基甲硅烷基）丁烷-1,2-二醇(8d)的X-射线单晶衍射确证。     

3-叠氮基-4-酰氯肟基呋咱的合成及其热稳定性

以3-氨基-4-酰氨肟基呋咱为原料,经重氮化和叠氮化反应合成了新化合物3-叠氮基-4-酰氯肟基呋咱(3),总收率67％.其结构经1H NMR,13C NMR,15N NMR,IR及元素分析表征.热失重法研究结果表明,3具有良好的热稳定性.     

Studies on the Syntheses and Biological Activities of 3-Aryl-6-(1,1'-biphenyl-4-yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines

IntroductionAmongst various heterocycles 3 ,6 -disubstituted- 7H- 1 ,2 ,4- triazolo[3 ,4- b][1 ,3 ,4]thiadiazines have received considerable attentionduring the lasttwo decades as potentially biologicalactive agents[1,2 ] . A literature survey indicated thatthis kind of N - bridged heterocycles displayed awide spectrum of biological properties,such asantimicrobial[3] ,antibacterial,antifungal[4 ] ,antiinflammatory[5] ,diuretic[6 ] ,anthelmintic,andanalgesic[7] . They can also be used as the p…     

A symmetric derivative of the trimetallic nitride endohedral metallofullerene, Sc3N@C80.

The reaction of Sc3N@C80 with 6,7-dimethoxyisochroman-3-one (13C labeled) provides the first functionalized derivative of the trimetallic nitride template (TNT) endohedral metallofullerene family. The reaction mixture is dominated by a single 13C labeled monoadduct product that was purified by HPLC. The 13C labeled monoadduct was characterized by 1H NMR, 13C NMR, and MALDI-TOF mass spectrometry. The proposed structure for this novel symmetric monoadduct is consistent with derivatization at the [5,6] ring juncture on the Sc3N@C80 cage.     

RuCl3/O2催化的叔胺与2-硅氧基呋喃衍生物的偶联反应研究

在RuCl3催化下, 分子氧作氧化剂, 叔胺和2-硅氧基呋喃衍生物发生氧化脱氢形成碳碳键的偶联反应. 水解后, 以良好的收率(88%)得到了相应化合物3, 用1H NMR, 13C NMR, IR, MS和HRMS对目标产物的结构进行了表征.     

含有联苯咔唑的富勒烯C60/C70衍生物的合成、 电化学性质和双光子吸收研究

富勒烯C60/C70与肌氨酸和联苯咔唑醛的1,3-偶极环加成反应, 获得了富勒烯C60/C70-联苯咔唑衍生物3和4, 用1H NMR, 13C NMR, MALDI-TOF-MS表征其结构; 研究了化合物3和4的紫外、荧光和电化学性质; 利用激光光解、Z扫描方法研究其双光子吸收特性.     

12H-双苯并[1,3,2]-二氧磷杂八环的合成与波谱分析

通过双（2-羟基-3,5-二氯苯基）甲烷（1）与ROPXCl_2 （X = O，S）的关环 反应，合成了6-烃氧基-6-氧（硫）-2,4,8,10-四氯-12H-双苯并[1,3,2]-二氧磷杂 八环（3），3（X = 0）的收率为62%-85%，并测试了3的~1H NMR，~(13)C NMR，~ (31)P NMR以及MS。详细报道了3的~(13)C NMR中存在的远程偶合现象，并探讨了3 的质谱裂解方式。     

NMR位移试剂Eu(fod)~4^-对锍盐^1H和^1^3C NMR的影响

合成了八种新的四氟硼酸二甲基苯基锍，用元素分析和核磁共振对其结构进行了表征。研究了以CDCl~3为溶剂，NMR位移试剂Eu(fod)~4^-对所合成锍盐的^1H和^1^3C NMR的影响。结果表明，Eu(fod)~4^-是一个对锍盐非常有效的位移试剂，且Eu(fod)~4^-对二甲基苯基锍盐之甲基的^1H和^1^3C NMR的位移呈线性关系。     

手性辅基诱导的含三氟甲砜基胺的不对称合成

以(S)-叔丁基亚磺酰亚胺和苄基三氟甲基砜类化合物为原料,正丁基锂（n-BuLi）为碱,THF为溶剂, Ti(OⁱPr)₄为路易斯酸,经不对称加成反应合成了一系列含三氟甲砜基的胺类化合物(3a~3j),产率45%~78%, d/r 50 ：26 ：24：0~85 ：7 ：6 ：2,其结构经¹H NMR, ¹³C NMR, ¹⁹F NMR, FT-IR和HR-MS(ESI)确证。采用X-ray单晶衍射研究了3i的构型。结果表明：3i的C1为R构型,C2为S构型。     

含硅香原料研究(Ⅵ)——顺(反)-1-取代-3-三甲硅基环己醇的合成、13CNMR谱及其香气评定

合成并分离得到7对1-取代-3-三甲硅基环己醇的顺、反异构体,它们的结构通过¹HNMR、¹³CNMR、MS谱及GC(测其纯度)测定,利用¹³CNMR确定了各对顺、反异构体的构型.评定了各化合物的香气,大部分化合物具有甜香或甜香与木香香气,其中(反)-1-正丁基-3-三甲硅基环己醇具有甜香和木香香气,香气透发,留香持久,质量上乘.     

Lamellar structure in poly(ala-gly) determined by solid-state NMR and statistical mechanical calculations

Lamellar structure of poly(Ala-Gly) or (AG)n in the solid was examined using 13C solid-state NMR and statistical mechanical approaches. Two doubly labeled versions, [1-13C]Gly14[1-13C]Ala15- and [1-13C]Gly18[1-13C]Ala19 of (AG)15 were examined by two-dimensional (2D) 13C spin diffusion NMR in the solid state. In addition five doubly labeled [15N,13C]-versions of the same peptide, (AG) 15 and 15 versions labeled [3-13C] in each of the successive Ala residues were utilized for REDOR and 13C CP/MAS NMR measurements, respectively. The observed spin diffusion NMR spectra were consistent with a structure containing a combination of distorted beta-turns with a large distribution of the torsion angles and antiparallel beta-sheets. The relative proportion of the distorted beta-turn form was evaluated by examination of 13C CP/MAS NMR spectra of [3-13C]Ala-(AG)15. In addition, REDOR determinations showed five kinds of atomic distances between doubly labeled 13C and 15N nuclei which were also interpreted in terms of a combination of beta-sheets and beta-turns. Our statistical mechanical analysis is in excellent agreement with our Ala Cbeta 13C CP/MAS NMR data strongly suggesting that (AG)15 has a lamellar structure.     

膜荚黄芪苷元的结构

从膜荚黄芪的根中分得膜荚黄芪皂苷甲,皂苷乙和皂苷丙.膜荚黄芪皂苷甲是主要成分.药理试验有降压和抗炎作用、皂苷甲经Smith氧化降解得到膜荚黄芪苷元1.用IR,~1HNMR,~(13)C NMR,MS和化学降解证明其结构为1.根据镧系位移试剂的~1H NMR,1的C_(20)和C_(24)的构型分别确定为S和R.     

Trachylobagibberellin类似物的化学合成研究（Ⅰ）──12．16R－环赤霉低酸甲酯的合成

Ｔｒａｃｈｙｌｏｂａｇｉｂｂｅｒｅｌｌｉｎ类似物的化学合成研究（Ⅰ）──１２．１６Ｒ－环赤霉低酸甲酯的合成谢文革，崔育新，马建泰，潘鑫复（兰州大学化学系，兰州大学应用有机化学国家重点实验室，兰州，７３００００）关键词Ｔｒａｃｈｙｌｏｂａｇｉｂｂｅｒｅ...     

Amberlyst-15催化C(sp~3)—H对靛红类化合物的加成反应

以Amberlyst-15为催化剂,甲基吡啶类化合物中的C(sp~3)—H键对靛红类化合物经加成反应合成了24个3-羟基-2-吲哚酮类化合物(3a~3x),其中3u~3x为新化合物,其结构经1H NMR,13C NMR,IR和HR-MS(ESI)表征。催化剂Amberlyst-15循环使用8次,不影响反应收率。     

The structure of poly(carbonsuboxide) on the atomic scale: a solid-state NMR study

In this contribution we present a study of the structure of amorphous poly(carbonsuboxide) (C3O2)x by 13C solid-state NMR spectroscopy supported by infrared spectroscopy and chemical analysis. Poly(carbonsuboxide) was obtained by polymerization of carbonsuboxide C3O2, which in turn was synthesized from malonic acid bis(trimethylsilylester). Two different 13C labeling schemes were applied to probe inter- and intramonomeric bonds in the polymer by dipolar solid-state NMR methods and also to allow quantitative 13C MAS NMR spectra. Four types of carbon environments can be distinguished in the NMR spectra. Double-quantum and triple-quantum 2D correlation experiments were used to assign the observed peaks using the through-space and through-bond dipolar coupling. In order to obtain distance constraints for the intermonomeric bonds, double-quantum constant-time experiments were performed. In these experiments an additional filter step was applied to suppress contributions from not directly bonded 13C,13C spin pairs. The 13C NMR intensities, chemical shifts, connectivities and distances gave constraints for both the polymerization mechanism and the short-range order of the polymer. The experimental results were complemented by bond lengths predicted by density functional theory methods for several previously suggested models. Based on the presented evidence we can unambiguously exclude models based on gamma-pyronic units and support models based on alpha-pyronic units. The possibility of planar ladder- and bracelet-like alpha-pyronic structures is discussed.     

重水中固氮酶催化还原乙炔产物的^1H NMR研究

用^1HNMR研究了固氮酶在重水中催化还原乙炔的反应产物氘代乙烯.种用群对称性对^1HNMR谱图进行了归属,计算了几种可能的C`2H~2D~2结构以及C~2H~3D结构的NMR谱线频和强度,得出了理论谱.通过理论谱与实验谱的比较,表明固氮酶在重水中催化还原乙炔的产物主要以顺式结构C~2H~2D~2为主,并含有较多的单氘代烯.单氘代乙烯相对乙烯的化学位移往高场移动约4.0Hz,而双氘代乙烯向高场的位移大约是单氘代乙烯的2倍左右。