樟脑酮亚胺衍生物的合成及立体结构研究

从d-樟脑出发,经六步反应合成了一种新的樟脑酮亚胺衍生物——7,7-二甲基一双环[2.2.1]-2-(苄)亚胺-10-(N-邻羟基苯基)酰胺(2)。化合物的晶体的晶胞参数a=8.6904(9),b=10.9400(16),c=20.8583(33)A;z=4.V=1983.06(o.45)A~3;属P2_12_12_1空间群。用反常散射法测定分子的绝对构型为1S,4R,并讨论了该化合物作为不对称反应合成子的立体选择性的影响因素。     

以(+)-樟脑缩苄胺作中间体对映选择合成(R)-α-取代苄胺

本文报道以(+)-樟脑作手性助剂, 苄胺为原料, 二者缩合制得的酮亚胺作中间体3,不对称合成(R)-α-取代苄胺(7)的一条有效新途径。化合物3用丁基锂去质子化提供的锂衍生物4和卤代烷反应, 以较高立体选择性产生烷基化产物6, 化合物6用醋酸羟胺转氨反应后, 获得了光学产率为4.6-90%的(R)-α-取代苄胺(7), 以肟的形式回收(+)-樟脑。     

新型(十)-樟脑酮亚胺的Pd(II)、Co(II)配合物的晶体结构研究

(+)-樟脑与6-甲基-2-氨甲基吡啶缩合得到一种新的手性双齿配体-1,7,7-三甲基-双环[2.2.1]-2-(6'-甲基-2'-氨甲基)吡啶亚胺(1), 与二价钯生成配合物2, 晶体属P21空间群, 晶胞参数为a=10.641(2), b=10.706(2), c=11.011(2)埃; β=115.63(1)°;V=1131.15(40)埃^3; Z=2, 二价钴与1生成配合物3, 晶体属PI空间群, 晶胞参数为a=7.429(2), b=7.971(3), c=16.304(5)埃; a=80.19(3), β=77.10(2), γ=83.21(2)°; V=924.25(56)埃^3; Z=2。根据晶体数据讨论了分子的结构特征, 并对配合物的红外、紫外和核磁共振谱的变化作了解释。     

新型(十)-樟脑酮亚胺的Pd(II)、Co(II)配合物的晶体结构研究

(+)-樟脑与6-甲基-2-氨甲基吡啶缩合得到一种新的手性双齿配体-1,7,7-三甲基-双环[2.2.1]-2-(6'-甲基-2'-氨甲基)吡啶亚胺(1), 与二价钯生成配合物2, 晶体属P21空间群, 晶胞参数为a=10.641(2), b=10.706(2), c=11.011(2)埃; β=115.63(1)°;V=1131.15(40)埃^3; Z=2, 二价钴与1生成配合物3, 晶体属PI空间群, 晶胞参数为a=7.429(2), b=7.971(3), c=16.304(5)埃; a=80.19(3), β=77.10(2), γ=83.21(2)°; V=924.25(56)埃^3; Z=2。根据晶体数据讨论了分子的结构特征, 并对配合物的红外、紫外和核磁共振谱的变化作了解释。     

选择性合成双[噻吩并[2,3-d]嘧啶-4(3H)-酮]

以2-氨基-4-三氟甲基-5-甲基-噻吩-3-羧酸乙酯(1)为起始原料制得膦亚胺2.在碳酸钾的催化下,膦亚胺2与芳基异氰酸酯和伯二胺的氮杂Wittig反应制得嘧啶环上2,2’取代的双[噻吩并[2,3-d]嘧啶-4(3H)-酮]3;膦亚胺2与烷基异氰酸酯和伯二胺的氮杂Wittig反应制得嘧啶环上3,3’取代的双[噻吩并[2,3-d]嘧啶-4(3H)-酮]4.化合物3的核磁共振氢谱表明关环反应在嘧啶环的2,2’位;化合物4的核磁共振氢谱表明关环反应在嘧啶环的3,3’位.对合成反应机理的推导及目标产物核磁共振氢谱数据的分析解释了此合成反应的选择性.     

含吡唑基的1,5-苯并硫氮杂衍生物的合成及晶体结构

以1-苯基-3-甲基-5-苯氧基-吡唑-4-甲醛和1-苯基-3-甲基-5-对甲苯氧基-吡唑-4-甲醛为原料, 在碱性条件下与苯乙酮(取代苯乙酮)发生羟醛缩合, 合成出10种新型含吡唑基的查尔酮; 再用此查尔酮与邻氨基硫酚在冰醋酸中反应, 合成了10种新的1,5-苯并硫氮杂, 化合物的结构经元素分析、IR和1H NMR确认, 同时测定了化合物6c的晶体结构. 化合物6c属单斜晶系(Monoclinic), 空间群P2(1)/n, 晶胞参数a=1.1793(2) nm, b=1.1907(2) nm, c=1.8726(4) nm, α=90°, β=104.71(3)°, γ=90°, M=522.04, V=2.5432(9) nm3, Dc=1.363 Mg/m3, Z=4, F(000)=1088.     

含吡唑基的1,5-苯并硫氮杂衍生物的合成及晶体结构

以1-苯基-3-甲基-5-苯氧基-吡唑-4-甲醛和1-苯基-3-甲基-5-对甲苯氧基-吡唑-4-甲醛为原料,在碱性条件下与苯乙酮(取代苯乙酮)发生羟醛缩合,合成出10种新型含吡唑基的查尔酮;再用此查尔酮与邻氨基硫酚在冰醋酸中反应,合成了10种新的1,5-苯并硫氮杂,化合物的结构经元素分析、IR和1HNMR确认,同时测定了化合物6c的晶体结构.化合物6c属单斜晶系(Monoclinic),空间群P2(1)/n,晶胞参数a=1.1793(2)nm,b=1.1907(2)nm,c=1.8726(4)nm,α=90°,β=104.71(3)°,γ=90°,M=522.04,V=2.5432(9)nm3,D=1.363Mg/m3,Z=4,F(000)=1088.     

2-(4-甲硫苯氧基)-3-(4-甲苯基)-4H-咪唑啉-4-酮衍生物的合成及杀菌活性(Ⅱ)

用烯基膦亚胺与4-甲苯基异氰酸酯、对甲硫苯酚的串联aza-Wittig反应合成了2-(4-甲硫基苯氧基)-3-(4-甲苯基)-4H-咪唑啉-4-酮衍生物.探讨了反应进行的条件和产物的波谱性质,提出了可能的环化反应机理.生成的环化产物均为新的化合物,其结构经元素分析、IR、1H NMR和MS确证.并探讨了所合成的新型杂环化合物的生物活性,结果表明部分化合物表现出良好的抑菌活性,其中3f的活性最好,在质量分数为5×10-5浓度时,对稻瘟菌和苹果轮纹菌的抑制率均达到100%.     

2-烷氧基-3H-喹唑啉-4-酮的合成与杀菌活性

研究了合成2-烷氧基-3H-喹唑啉-4-酮衍生物4的方法,该方法应用膦亚胺1与芳基异氰酸酯的氮杂Wittig反应,得到的碳二亚胺2再与醇在醇钠催化下反应,合成了12种未见文献报道的喹唑啉酮衍生物4.所得产物4的结构由NMR,MS,IR所确证.探讨了成环反应的条件以及所合成的新型杂环化合物的杀菌活性,结果表明部分化合物表现出较好的抑菌活性,如41在50 mg/L浓度时,对水稻纹枯菌的抑制率为89%.     

亲电硫试剂参与的2-芳基-3-硫代-2,3-二氢喹啉-4(1H)-酮的合成研究

本文报道了以(E)-1-(2-对甲苯磺酰胺基)-3-芳基丙-2-烯-1-酮(1)为底物与N-硫代丁二酰亚胺(2)通过亲电环化反应合成2-芳基-3-硫代-2,3-二氢喹啉-4(1H)-酮类化合物。以三氟化硼乙醚为催化剂(20 mol %),1,2-二氯乙烷为溶剂,反应温度为60 _oC,可以60-92%的收率得到一系列2-芳基-3-硫代-4(1H)-喹啉酮衍生物,化合物3a-k均未见文献报道,其结构均经过₁H NMR, ₁₃C NMR以及高分辨质谱进行确定。     

Single—Molecular Imaging of Anticoagulation Factor I From Snake Venom by Atomic Force Microscopy

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The role of orbiting resonances in the vibrational relaxation of I(2)(B,v' = 21) by collisions with He at very low energies: a theoretical and experimental study

The low-energy collisions of I(2)(B,v' = 21) with He involving collision-induced vibrational relaxation of I(2) are investigated both experimentally and by means of wave packet simulations. The theoretical cross sections exhibit a structure of peaks originated by orbiting resonances of the I(2)(B,v' = 21) - He van der Waals complex formed in the I(2) + He collisions. Such a structure has similar characteristics as the structure of peaks found in the experimental cross sections. In fact, four of the five peaks of the measured cross sections appear at positions nearly coincident with those of four of the peaks found in the theoretical cross sections. Thus this result confirms the experimental finding that enhancement of I(2) vibrational relaxation is caused by the population of I(2)(B,v' = 21) - He orbiting resonances populated upon the low-energy collisions. The possibility of using this mechanism in the vibrational cooling of diatomic molecules is discussed.     

Clarithromycin form I determined by synchrotron X‐ray powder diffraction

The structure of the metastable form I polymorph of the macrolide antibiotic clarithromycin, C₃₈H₆₉NO₁₃, was determined by a powder diffraction method using synchrotron radiation. The space group of form I is P2₁2₁2. The initial model was determined by a molecular replacement method using the structure of clarithromycin form 0 as a search model, and the final structure was obtained through Rietveld refinements. In the form I crystal structure, the clarithromycin molecules are aligned parallel along the a axis in a head‐to‐tail manner with intermolecular hydrogen bonds between the hydroxy O atoms. The dimethylamine groups of the clarithromycin molecule interdigitate between neighbouring head‐to‐tail clarithromycin alignments. The novel crystal packing found in form I provides a mechanism that describes the transformation of form 0 to form I.     

STRUCTURE OF A THYMINE-THYMINE ADDUCT FORMED BY MENADIONE PHOTOSENSITIZATION

Abstract— The structure of one of the dithymine adducts formed by near-UV photosensitization of aqueous oxygenated thymine in the presence of 2-methyl- 1, 4-naphthoquinone is reported. The compound, 6'β-hydroxy-5'β-1 - [5-methylpyrimidinyl- 2,4-dione]-5'-6'-dihydrothymine has one thymine ring (ring I) linked through the 1-nitrogen atom to the C5' atom of a second thymine, which has been hydroxylated af C6' (ring II). Crystals are monoclinic, space group 12/c, and the structure was refined to R_obs= 0.036 for 2072 unique reflections with intensities I greater than 2.33(I). Ring I is planar, whereas ring II is not. Ring I and the OH group on ring II are cis to ring II. The planar ring I and the OH group are attached, respectively, in an equatorial and axial manner to ring II (which is in the sofa conformation). The planar rings I of close-lying pairs of molecules stack parallel to each other. The structure is held together by a hydrogen-bonding system consisting of the water molecules, the NH groups, two of the C=O groups and the OH group. The chemical formula and relative configurations at C5' and C6 are established by this analysis.     

STRUCTURE AND CATALYTIC PROPERTIES OF PALLADIUM(II) (ACETYLACETONATO- κ2O,O′)BIS(TRIS(DIETHYLAMINO)PHOSPHINE) TETRAFLUOROBORATE

Journal of Structural Chemistry - The structure of complex [Pd(acac){P(NEt2)3}2]BF4 (I) is determined by XRD. In the crystal structure of I, the coordination sphere of palladium is characterized by...     

Versatility of the electronic structure of compound I in catalase-peroxidases

Catalase-peroxidases (KatGs) are bifunctional heme proteins, belonging to the family of class I peroxidases, that are able to catalyze both catalatic and peroxidatic reactions within a peroxidase-like structure. We investigated the electronic structure of reaction intermediates of the catalytic cycle of KatGs by means of density functional theory (DFT) QM/MM calculations. The outcome was that the ionization state of the KatG-specific covalent adduct (Met264-Tyr238-Trp111) affects the radical character of compound I (Cpd I). Specifically, in the optimized structures, substantial radical character is observed on the proximal Trp330 when Tyr238 is protonated, whereas when Tyr238 is deprotonated the radical localizes on the Met+-Tyr(O-)-Trp adduct. These findings are not affected by protein thermal fluctuations, although details of the spin density distribution are affected by the geometry of the active site. Calculations provide structures in good agreement with the crystal structure of BpKatG Cpd I. They also provide an explanation for the experimental findings of the mobile and catalatic-specific residue Arg426 being 100% in conformation R in the X-ray structure of BpKatG treated with organic peroxides. The role of different Cpd I forms in the catalase and peroxidase reaction pathways is discussed.     

Kristall- und Molekülstruktur von Tris(1,1-diethyl-3-benzoylthioharnstoff)silber(I)-hydrogensulfid

Crystal and Molecular Structure of Tris(1,1-diethyl-3-benzoylthiourea)silver(I) Hydrogensulfide . The crystal structure of tris(1,1-diethyl-3-benzoylthiourea)silver(I) hydrogensulfide has been determined by X-ray crystal structure analysis. The substance crystallizes monoclinic, space group P2₁/n with a = 8.181, b = 20.216, c = 25.035 Å, β = 98.21° and 4 formula units per unit cell. The structure was solved by heavy atom technique and refined to a final R value of R = 0.046. Silver(I) does not form a chelate with the ligand 1,1-diethyl-3-benzoylthiourea. Three molecules of the ligand coordinate monodentately via the S atoms while a fourth coordination position is occupied by a hydrogensulfide ion. The coordination polyhedron is a distorted tetrahedron.     

Deviation from the planarity--a large Dy3N cluster encapsulated in an Ih-C80 cage: an X-ray crystallographic and vibrational spectroscopic study

The high-yield synthesis of Dy3N@C80 (I) opens the possibility of characterizing its molecular and vibrational structures. We report on the structure determination of Dy3N@C80 (I) by X-ray crystallographic study of single crystal of Dy3N@C80.Ni(OEP).2C6H6, revealing a nearly planar Dy3N cluster encapsulated in an Ih-C80 cage. The vibrational structure of Dy3N@C80 (I) is studied by Fourier transform infrared (FTIR) and Raman spectroscopy in combination with force-field calculations. A correlation was found between the antisymmetric metal-nitrogen stretching vibration and the structure of the M3N cluster of M3N@C80 (I) (M = Y, Gd, Tb, Dy, Ho, Er, Tm). Moreover, a stronger interaction between the encaged nitride cluster and the C80 carbon cage was found in the class II M3N@C80 (I) (M = Y, Gd, Tb, Dy, Ho, Er, Tm) than in Sc3N@C80 (I). This study demonstrates that the cluster size plays the dominating role in the structure of the M3N cluster in M3N@C80 (I).     

碘掺杂双酞菁镥结构和电学性能的研究

用饱和碘蒸气掺杂双酞菁镥(Pc2LuH)得到组成为(Pc2LuH.I6)的电荷转移复合物。碘掺杂后仍保持原来Pc2LuH分子的夹心结构, 但使沿酞菁环平面方向上彼此分子间靠近。碘未取代酞菁环上的氢; 因为酞菁配位基, 特别是氮原子向碘转移的电子, 形成I3^-,这样就有了氧化态的共轭分子和还原态的I3^-分别堆砌成两个有序的分子柱, 具备了一维导体的聚集态结构, 用夹心池样品得到ρ25℃=1.58×10^2Ω.cm, ΔE=0.1eV。     

The structure of dimers and the nature of azulene chromaticity

The structure of supramolecular azulene dimers responsible for the blue coloration of its crystals and solutions has been discussed on the basis of result of optical spectroscopy and literature data. It is established that two types of these dimers (I and II) absorb the light in the red region of the visible (VIS) spectrum and differ by the mutual orientation of the molecules. Dimers I have a VIS band with a vibronic structure; the azulene molecules in dimers I match their own seven-membered rings in type (stacking structure), and five-membered rings of the molecules are separated so that the molecular C _2v axes form an obtuse angle. The spectra of dimers II do not have a vibronic structure in the VIS band. The dipole moments of the molecules in these dimers are oriented antiparallel (five-membered rings are located over (or under) seven-membered rings, forming a structure with a center of inversion). It is concluded that due to their structure, dimers I should have a certain dipole moment, while dimers II have no dipole moment.