Lewis base-assisted Lewis acid-catalyzed selective alkene formation via alcohol dehydration and synthesis of 2-cinnamyl-1,3-dicarbonyl compounds from 2-aryl-3,4-dihydropyrans

Acid-catalyzed dehydration of alcohols has been widely employed for the synthesis of alkenes. However, activated alcohols when employed as substrates in dehydration reactions are often pla-gued by the lack of alkene selectivity. In this work, the reaction system can be significantly improved through enhancing the performance of Lewis acid catalysts in the dehydration of activated alcohols by combining with a Lewis base. Observations of the reaction mechanism revealed that the Lewis base component might have changed the reaction rate order. Although both the principal and side reaction rates decreased, the effect was markedly more observed on the latter reaction. Therefore, the selectivity of the dehydration reaction was improved. On the basis of this observation, a new route to synthesize 2-cinnamyl-1,3-dicarbonyl compounds was developed by using 2-aryl-3,4- di-hydropyran as a starting substrate in the presence of a Lewis acid/Lewis base combined catalyst system.

6-氟-4-羟基-3-氧代-3,4-二氢喹喔啉-1(2 H)-羧酸叔丁酯的合成、晶体结构及抗肿瘤活性研究

喹喔啉类化合物由于具有显著的生物活性而被广泛应用于医药、化工领域,特别是抗癌药物研发领域。本文通过四步反应法首次合成了6-氟-4-羟基-3-氧代-3,4-二氢喹喔啉-1(2 H)-羧酸叔丁酯,经溶液结晶法获得其单晶体。晶体学分析表明,该化合物属单斜晶系,空间群C2/c,晶胞常数a=1.28663(10)nm,b=2.25249(17)nm,c=1.01564(7)nm,Z=8,ρ_(c)=1.359 g·cm^(-3),R=0.0538,R_(w)=0.1406。在B3LYP/6-311+G(2d,p)模式下使用密度泛函理论(DFT)计算了该化合物的最佳结构,与X射线单晶衍射确定的晶体结构基本一致。抗肿瘤活性研究表明其有良好的抗肿瘤作用。此外,通过DFT计算了分子的静电势和前沿分子轨道。

Formation of Hybrid Ring Structure of Cyanurate/Isocyanurate in the Reaction be-tween 2,4,6-Tris(4-Phenyl-Phenoxy)-1, 3,5-Triazine and Phenyl Glycidyl Ether

Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.

Crystal Structure and Theoretical Studies of Tetrahytrate(1-H-1,2,4-triazole-3,5-dicarboxylicacid)nickel

A new compound, [Ni（Hdctrz）（H2O）4]（1, H3dctrz = 1-H-1,2,4-triazole-3,5-dicarboxylic acid）, has been successfully synthesized via slow evaporation. The structure of 1 was characterized by FT-IR, elemental analysis and single-crystal X-ray diffraction. Compound 1 crystallizes in monoclinic, space group P21/c with a = 6.871（1）, b = 11.468（1）, c = 12.178（1） A, b = 101.291（1）o, V = 941.01（16） A3, Z = 4, C4H9N3O8Ni, Mr = 285.85, Dc = 2.018 g·cm–3, m = 2.10 mm–1, F（000） = 584, GOOF = 1.025, the final R = 0.0515 and wR = 0.2125 for 1404 observed reflections（I 〉 2s（I））. The crystal structure is assembled by a slightly distorted {NiNO5} octahedral geometry and hydrogen bonds viz. N–H…O, O–H…O, C–O…π and π···π weak interactions. A rare π···π interaction from triazolate and carboxylate is affirmed through the molecular orbitals（MO） of three adjacent Ni CN molecules. The 3D Hirshfeld surface analysis was employed to gain additional insight into the interactions responsible for the packing of compound 1. Quantitative examination of 2D fingerprint plots revealed, amongst others, the dominating participation of O···H, N···H and π···π interactions in the molecular packing.

Synthesis, Crystal Structure and Antitumor Activity of (E)-1-(7-Methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5- yl)-3-(2-methoxyphenyl)-2-(1H-1,2,4-triazol-1-yl)propenol

The title compound, （E）-1-（7-methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl）- 3-（2-methoxyphenyl）-2-（1H-1,2,4-triazol-1-yl）propenol （3a）, was synthesized by the Aldol con- densation reaction of 1-（7-methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl）-2-（1,2,4-triazol- 1-yl）ethanone with 2-methoxybenzaldehyde and then reduced with NaBH4, and its crystal structure was determined by single-crystal X-ray diffraction： monoclinic system, space group P21 with a = 6.2002（3）, b = 12.8452（7）, c = 13.2257（7） ？, Z = 2, V = 1031.23（9） ？3, Mr = 407.46, Dc = 1.312 Mg/m3, S = 1.054, μ = 0.091 mm-1, F（000） = 432, the final R = 0.0353 and wR = 0.0769 for 3161 observed reflections （I 〉 2σ（I））. X-ray analysis displays that the title compound adopts an E configuration for the C（7）=C（8） double bond and S configuration for the chirality center with the specific rotation of –63.75°. Furthermore, the stability of the crystal was maintained through the intermolecular hydrogen bond O（1）–H？？？N（3）. The antitumor assay exhibits that the title compound 3a （E configuration） has a good antitumor activity against the Hela cell line with the IC50 value of 36.9 μM, which is better than that of 3b （Z configuration）.

Syntheses and Characterization of Two New Alkaline Earth Metal-organic Topological Frameworks with 3-Amino-1H-1,2,4-triazole-5-carboxylate

Two new alkaline earth metal coordination polymers constructed from the deriva-tive of 1,2,4-triazole are presented herein,namely,{[Sr（AmTAZAc）2（H2O）]}（1） and {[Ba（AmTAZAc）2（H2O）]}（2）（AmTAZAc = 3-amino-1H-1,2,4-triazole-5-carboxylate）,which have been synthesized by using the layering method and structurally characterized by elemental analysis,IR,and single-crystal X-ray diffraction.Complexes 1 and 2 are isostructural,and both crystallize in the orthorhombic system,space group Fdd2.X-ray structural analysis shows that 1 or 2 has an intriguing 3-D infinite network of（318.438.510） topology based on a 2-D sheet structure of（4,4） net.The result shows that noncovalent interactions play an important role in strengthening the whole structures of the compounds.

Syntheses, Characterization and Biological Activity of Coordination Compounds of 3-Hydroxy-2-methyl-4<i>H</i>-pyran-4-one and Its Mixed Ligand Complexes with 1,2-Diaminocyclohexane

Coordination compounds of 3-hydroxy-2-methyl-4H-pyran-4-one with iron(III), cobat(III) and chromium(III) were synthesized with M:L (1:2). Mixed ligand coordination compounds of 3-hydroxy-2-methyl-4H-pyran-4-one and 1,2-diaminocyclohexane using the same metal ions were also synthesized M:L1:L2 (1:1:1) where L1 is 3-hydroxy-2-methyl-4H-pyran-4-one and L2 is 1,2-diaminocyclohexane. The coordination compounds obtained were characterized using electronic and infrared spectral analyses, magnetic susceptibility and percentage metal analysis. They were also evaluated for their cytotoxic and antioxidant activities. The result obtained suggested that octahedral geometry was obtained for all the compounds, as a result of additional two molecules of the solvent coordinated to the metal ions. Both the primary and secondary ligands coordinated in a bidentate fashion. The synthesized compounds exhibited moderate cytotoxicity, although none was as active as the standard. The cobalt(III) mixed ligand complex elicited the highest activity. The synthesized compounds all exhibited good to moderate antioxidant activity.

2-取代-1,3-二硫杂环戊烷香料的合成和香气评价

以醛／酮与1，2-乙二硫醇或1，2-丙二硫醇在对甲苯磺酸催化下反应，合成了10种2-取代-1，3-二硫杂环戊烷，产率62．8％～87．8％；其中，2-正丙基-1，3-二硫杂环戊烷产率达87．8％，纯度99．5％。经元素分析、FTIR、GC-MS和’HNMR确定了10种产物的结构。香气评价结果表明：合成的2-正丙基-1，3-二硫杂环戊烷具有花香、肉汤香气，可用于食品香精和调味料中；其余9种2-取代-1，3-二硫杂环戊烷具有肉香、葱蒜香和萝卜香。

Synthesis, Crystal Structure and Fungicidal Activity of (Z)-3,3-Dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one O-2-Chlorobenzyl Oxime Nitrate

The title compound has been synthesized by the reaction of 3,3-dimethyl-1-（1H-1,2,4-triazol-1-yl）butan-2-one oxime with 2-chlorobenzyl chloride, and then treated with 65～68% HNO3. Its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 14.5481（8）, b = 9.3351（5）, c = 13.1911（7） , β = 98.9450（10）°, Z = 4, V = 1769.67（17） 3, Mr = 369.81, Dc = 1.388 g/cm3, S = 1.06, μ = 0.247 mm-1, F（000） = 776, the final R = 0.0352 and wR = 0.0960 for 3069 observed reflections （I 2σ（I））. X-ray crystal structure presents the intramolecular N–H…O hydrogen bond. The packing is nearly parallel without π-π stacking interactions between two adjacent phenyl rings and stabilized by Van der Waals force. The preliminary bioassay shows that the title compound possesses fungicidal activity against Gibberella zeae at the dosage of 25 mg/L.

Synthesis,Crystal Structure and Plant Growth Regulatory Activity of 1-(3-Amino-[1,2,4]triazol-1-yl)-3,3-dimethyl-butan-2-one

The title compound 1-（3-amino-[1,2,4]triazol-1-yl）-3,3-dimethyl-butan-2-one（3） was synthesized by Hofmann-alkylation reaction of 1-chloro-3,3-dimethyl-butan-2-one（1） and ~1H-[1,2,4]triazol-3-ylamine（2） with equal amount of K_2CO_3 as acid acceptor. The structure of compound 3 was characterized by ~1H NMR, 13 C NMR, HRMS and single-crystal X-ray diffraction. The compound crystallizes in the monoclinic system, space group P21/n with a = 5.7227（8）, b = 27.924（4）, c = 6.2282（7） ？, β = 101.892（11）°, V = 973.9（2） ？~3, Z = 4, T = 180.00（10） K, μ（MoKα） = 0.087 mm^（-1）, Dc = 1.243 g/cm^3, 3832 reflections measured（3.648≤θ≤26.022°）, 1916 unique reflections（Rint = 0.0359, Rsigma = 0.0572） used in all calculations. The final R = 0.0557（I 〉 2σ（I）） and w R = 0.1276（all data）. Bioassay showed that 3 displayed excellent activity as plant growth regulator with inducing lateral root formation and enhancing primary root elongation at 0.27 mmol/L（50 ppm） in soybeen（He Feng-50）. Good water solubility was found with 50 mg in 1 m L of water. Therefore, application of 3 in agriculture is more environmentally friendly due to cosolvent-free condition, and results in improved abiotic-stress tolerance by affecting the root growth. And furthermore, it can be used as a precursor to investigate the function of regulating plant root growth.

Syntheses of Coordination Compounds of 2-Amino-3-Methylbutanoic Acid Their Mixed Ligand Complexes and Antibacterial Activities

Coordination compounds of 2-amino-3-methylbutanoic acid were synthesized with chromium(III) and oxovanadium(IV) ions. M:L;1:2. Adducts of these complexes using 1,10-phenantroline and ethylenediamine were further synthesized, M:L, (1:2). These compounds were characterized using electronic, infra-red spectrophotometry, magnetic susceptibility measurement and percentage metal analyses. The zones of inhibition and minimum inhibitory concentrations of the compounds against eight microbes were studied. The results obtained indicated an octahedral geometry for the Cr(III) complexes, indicative of additional coordination of two water molecules. On the other hand a square pyramid geometry was obtained for the binary oxovanadium complex and its 1,10-phenantroline adduct. However, for the oxovanadium ethylenediamine adduct a distorted octahedral geometry was proposed. The result for the antibacterial studies indicated that both mixed ligand complexes of 1,10-phenantroline exhibited good antibacterial activity, and in some cases better activity than the standard, streptomycin.

1甲-基-3,5二-硝基-1,2,4三-唑的合成及表征

以双氰胺、二盐酸肼为起始原料,经缩合环化、重氮化硝化、甲基化等三步反应合成1-甲基-3,5-二硝基-1,2,4-三唑（MDNT）,总收率为16.75%。精制后,熔点95~96℃,纯度大于99%,用核磁氢谱（1H NMR）、红外光谱（IR）、元素分析对其结构进行了表征。同时,改善了3,5-二氨基-1,2,4-三唑（DAT）的萃取工艺,改用热的甲醇萃取,DAT收率由89.0%提高到96.5%。用差示扫描量热法（DSC）研究了MDNT的热分解性质。结果表明,MDNT的热分解分为两个阶段,分别为95.7℃和230.2℃,它的熔化热为16.505 kJ.mol-1,分解热为112.582 kJ.mol-1。

2,6-双-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑吡啶类衍生物的合成及抗菌活性

芳香羧酸酯化、肼解、成盐、环化成3-芳基-4-氨基-5-巯基-1,2,4-三唑与2,6-吡啶二甲酸在相转移催化剂四丁基碘化铵和POCl3作用下,高产率制得8种标题化合物,并利用IR、1HNMR、MS和元素分析对目标化合物的结构进行了表征。初步的抗菌实验表明,部分目标化合物表现出较好的抑菌活性。

3,5-二硝基-1,2,4-三唑盐的制备

以双氰胺与二盐酸肼为原料,经缩合环化、重氮化、硝化得到3,5-二硝基-1,2,4-三唑(DNT)的水溶液,通过碳酸氢钠及硝酸银分别得到DNT的钠盐及银盐,得率分别为67.2%、33.6%。精制后,钠盐m.p.139～141℃,银盐m.p.235～238℃并通过红外光谱(IR)对其结构进行了表征。

“点击”化学合成1-苄基-4-三氟甲基-5-苯甲醇基-1,2,3-三氮唑

溴化苄和叠氮化钠为原料,通过叠氮化反应制得叠氮苄,反应收率达73.6%。2,3-二溴-1,1,1-三氟丙烷为原料,通过烯化、炔基化制得1-苯基-4,4,4-三氟-2-丁炔-1-醇,反应收率达75.5%。1-苯基-4,4,4-三氟-2-丁炔-1-醇和叠氮苄,在[Cp*RuCl2]n催化下通过1,3-偶极环加成反应首次合成了标题化合物,反应收率达到89.2%。产物结构经IR、1HNMR、19FNMR、13CNMR、ESI-MS和元素分析确证。

1-取代苄基-4-乙酰基-5-甲基-1,2,3-三唑的合成

以取代溴苄为原料,经取代和1,3-偶极环加成反应,得到1-取代苄基-4-乙酰基-5-甲基-1,2,3-三唑。实验表明,以无水碳酸钾为碱催化剂,乙腈和乙醇等体积混合为反应溶剂,物料配比n(取代苄基叠氮)∶n(乙酰丙酮)=1∶1.2,反应时间约为2 h,产品收率92%。目标化合物的结构得到1H NMR、MS和IR证实。

酸性离子交换树脂催化4-芳基-1H-1,2,3-三唑的合成

以酸性离子交换树脂Amberlite IR-120为催化剂,硝基烯烃和叠氮化钠为原料合成了一系列4-芳基-1 H-1,2,3-三唑衍生物。与常规方法相比,该法高效、反应条件温和且底物兼容性好。另外,催化剂通过过滤即可实现回收,重复使用6次后活性略有降低。

Gapped Spin-1/2 Spinon Excitations in a New Kagome Quantum Spin Liquid Compound Cu_3Zn(OH)_6FBr

We report a new kagome quantum spin liquid candidate CuaZn（OH）6FBr, which does not experience any phase transition down to 50inK, more than three orders lower than the antiferromagnetic Curie-Weiss temperature （-200 K）. A clear gap opening at low temperature is observed in the uniform spin susceptibility obtained from 19F nuclear magnetic resonance measurements. We observe the characteristic magnetic field dependence of the gap as expected for fractionalized spin-1/2 spinon excitations. Our experimental results provide firm evidence for spin fractionalization in a topologically ordered spin system, resembling charge fraetionalization in the fractional quantum Hall state.

含苯磺酰胺功能团的1,2,3-三唑类化合物的合成

以4-乙炔基苯磺酰胺和有机叠氮化合物为原料,以CuI-抗坏血酸钠为催化剂,通过1,3-二极环加成反应高产率地合成了一组标题化合物。目标化合物的结构1HNMR、13CNMR和元素分析予以确证。

PEG介质中2-[4-氨基-5-(2-苯并呋喃基)-4H-1,2,4-均三唑-3-巯基]-N-苯乙酰胺的合成

3-(2-苯并呋喃基)-4-氨基-5-巯基-1,2,4-三唑与氯乙酰苯胺衍生物在PEG-400介质中发生取代反应,制得相应的1,2,4-三唑-3-巯基-苯乙酰胺,产物结构经IR、NMR及元素分析进行了表征.结果表明,该方法具有产率高、污染少、操作简单、环境友好等优点.