立方氮化铝纳米晶的溶剂热合成及其对二甲苯催化性质的研究

低温 (2 80℃ )条件下 ,通过二甲苯中AlCl3 和NaN3 的反应制备出了AlN纳米微粒。 70 0℃退火 4 8h后 ,得到了纯的立方相AlN纳米晶。通过XRD、FTIR和定域电子衍射分析 ,验证了立方相AlN纳米晶的生成。经XRD和TEM分析 ,纳米晶的平均粒度约为 3nm。色质联 (GC MS)检测结果显示 ,由于AlN纳米颗粒对二甲苯的催化作用 ,使二甲苯发生聚合和杂化环反应 ,得到了二联苯、萘、蒽、三甲基咔唑及咔唑胺等多环芳烃。作为对比实验 ,分别研究了NaN3 和AlCl3 对二甲苯的催化性能 。

Recent advances in heterogeneous catalytic hydrogenation and dehydrogenation of N-heterocycles

The selective hydrogenation of quinolines to 1,2,3,4-tetrahydroquinolines(py-THQ) and its derivatives has attracted a considerable amount of attention as they show great versatility in many pharmaceuticals, agrochemicals, and fine chemicals. Over the past few decades, great breakthroughs have been achieved in the controlled synthesis of efficient heterogeneous catalysts used for the selective hydrogenation of functionalized quinoline compounds, which allow one to correlate the structure-property relationships. In this review, we will summarize the recent significant progress achieved in this field covering the synthetic strategies, microstructural and chemical features, catalytic performance, and internal relationships. State-of-the-art noble metal-based single(Pd, Pt, Ru, Rh, Ir and Au) and bi/multi-metallic catalysts(RuCu, AuPd, and PdNi) are first introduced, followed by a summary of earth-abundant metal-based catalysts(Co, Fe, Ni, and Cu). Finally, the dehydrogenation of N-heterocycles is introduced to form a reversible hydrogenation/dehydrogenation system for H2 storage, which can be employed in a liquid organic hydrogen system. Furthermore, the reaction mechanism and future research direction in these areas are also discussed. This review will deepen our understanding of the catalytic transformation of N-heterocycles and provide guidance for researchers on the rational design of catalysts.

H4SiW6Mo6O40-Doped Polyaniline-Synthesis, characterization and catalytic properties of acetals and ketals

A new environmental friendly catalyst, HaSiWrMo6O40/PAn was prepared and identified by means of FT-IR, XRD and TG/DTA. The optimum conditions have been found, that was, mass ratio of m（PAn）： m（HaSiW6Mo6On.） was 1：1.25, volume of methanol was 20 mL, and the reflux reaction time was 2h. The structural identity of Keggin units was preserved after the incorporation into polyaniline matrix. H4SiW6Mo6040/PAn was used as catalyst in catalytic synthesis of acetals and ketals. Effects of n（aldehyde（ketone ））： n（glycol）, catalyst dosage and reaction time on yield were investingated. Optimal conditions were： n（aldehyde（ketone））： n（glycol）=1.0： 1.5; mass fraction of catalyst to reactants, 0.5%; reaction time, 1.0 h and cyclohexane as water-stripped reagent, 15 mL. Under these conditions, yields of actels and ketals were 31.9%-91.6%.

Synthesis of Some More New Sulfur-containing Heterocyclic Compounds as Biocidal Agents- Part II： Synthetic of 2-thioxo thiazole/thia diazole and 3-thioxo-1,3,4-triazole Derivatives

Some new 2-thioxo thiazole, 2-thioxo 1,3,4- thiadiazole and 3-thioxo-1,3,4-triazole derivatives （3-17） have been synthesized through ring closure reactions ofdithioic formic acid hydrazones 2 with functional reagents in different medium. Former structures of the products have been established by the help of elemental and spectral analysis. Most of the obtained targets showed a moderate activity towards some microbes in comparison with two antibiotics Pipercillin and Mycostatine.

Efficient approach to thiazolidinones via a one-pot three-component reaction involving 2-amino-1-phenylethanone hydrochloride,aldehyde and mercaptoacetic acid

A highly efficient three-component reaction has been developed for the synthesis of thiazolidinones involving the reaction of 2-amino-l-phenylethanone hydrochloride with an aromatic aldehyde and mercaptoacetic acid in the presence of diisopropylethylamine in a single pot.Critically,this reaction exhibited excellent chemoselectivity,with the nitrogen atom of the 2-amino-l-phenylethanone component reacting selectively with the aromatic aldehyde to give the corresponding Schiff base.Nucleophilic attack at the carbon of the Schiff base by the sulfur atom of mercaptoacetic,followed by a cyclocondensation reaction between the nitrogen and the carboxylic acid moiety afforded the desired thiazolidinones,which were fully characterized by spectroscopic techniques.

Cascade Cross-Coupling/[3,3]-Sulfonium Rearrangement of Alkynyl Sulfoxides and Ynamides/Ynol Ethers to Construct Tetrasubstituted Furans

A transition-metal-free strategy for the synthesis of tetrasubstituted furans is reported.Promoted by boron trifluo-ride diethyl etherate,the reaction of alkynyl sulfoxides with ynamides/ynol ethers proceeded via a cascade process including cross-coupling of the two reactants,[3,3]-sulfonium rearrangement,and 5-exo-dig heterocyclization,leading to tetrasubstituted furan products.The resultant α-alkylthio groups can be used for further functionalization,such as to introduce other alkyl/aryl groups.

The applications of hypervalent iodine(Ⅲ) reagents in the constructions of heterocyclic compounds through oxidative coupling reactions

Hypervalent iodine(Ⅲ)reagents have been vastly used in many useful organic transformations.In this review article,we highlight the strategies that used the common hypervalent iodine(Ⅲ)reagents as oxidants to synthesize the heterocyclic compounds,based on the patterns of bond formation during the construction of the heterocyclic backbones.

Survey of recent advances of in the field of π-conjugated heterocyclic azomethines as materials with tuneable properties

This account gives an overview of our recent work in the area of conjugated azomethines derived from 2-aminothiophenes.It will be presented that mild reaction conditions can be used to selectively prepare symmetric and unsymmetric conjugated azomethines.It further will be demonstrated that azomethines consisting of various 5-membered aryl heterocycles lead to chemically,reductively,hydrolytically,and oxidatively robust compounds.The optical and electrochemical properties of these materials can be tuned contingent on the degree of conjugation,type of aryl heterocycle,and by including various electronic groups.The end result is materials having colors spanning 250 nm across the visible spectrum.These colors further can be tuned via electrochemical or chemical doping.The resulting doped states have high color contrasts from their corresponding neutral states.The collective opto-electronic properties and the means to readily tune them,make thiophenoazomethine derivatives interesting materials for potential use in a gamut of applications.

Zinc-assisted synthesis of imidazolium-tetrazolate bi-heterocyclic zwitterions with variable alkyl bridge length

Zinc halide-complexed alkyl-bridged bi-heterocycles were obtained as zwitterions from the Click reaction of a series of N-cyanoalkyl-N-alkylimidazolium halide ionic liquids with sodium azide. Reaction optimization showed fast reaction times and milder conditions compared to conventional Click syntheses from neutral nitriles.

Binaphthyl-bridged bis-imidazolinium salts as N-heterocyclic carbene ligand precursors in the palladium-catalyzed Heck reaction

Two new bis-imidazolinium salts (4a, 4b) have been synthesized as precursors of N-heterocyclic carbenes (NHCs) from the commercially available (R)-2,2′-dihydroxy-1,1′-binaphthalene. The two bis-imidazolinium salts were used as efficient precursor of NHC ancillary ligands in the palladium-catalyzed Heck reaction. Good to excellent yields and high stereoselectivities were obtained with ethyl acrylate, acrylonitrile, and acrylamide as starting materials. The structure of bis-imidazolinium salt 4b was further characterized by single crystal X-ray diffraction analysis.