A New Compound with C_2-Symmetry 3R,3'R-Dihydroxy-6,6',6,6'-tetramethyl-2R,2'R,-bis-4H-pyran

The title compound 1 was synthesized from 1.2:5,6-dianhydro-3,4-dianhydro-3,4-isopropylideneD-mannitol 2 through four steps in a total yield of 53%. The absolute configuration of this compound was confirmed by X-ray diffraction.

Synthesis of some new bis-3,4-dihydropyrimidin-2(1H)-ones by using silica-supported tin chloride and titanium tetrachloride

Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin -2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃under solvent-free conditions.

Gold （III） Complexes with Thiolactate and bis-（1,4-Sodiumthiolactate） Butane Ligands

The new ligand bis-（1,4-sodium thiolactate） butane （L）-O2CCH3S-（CH2）4SCHCH3CO2- has been prepared from the reaction of disodium salt of thiolactic acid and 1,4-dichlorobutane, while the disodium thiolactate was prepared instanteously through the reaction of thiolactic acid with NaOH. Mono and dinuclear complexes were obtained by direct reaction of the above ligands with H[AuCI4] in 1 ： 1, 2：1, 1：2, 2：2 and 3：1 ligands to metal molar ratio. The prepared complexes were characterized by elemental analysis, spectral studies FTIR （Fourier transform Infrared） and UV-Vis, magnetic measurement, conductivity measurement and IHNMR for the ligand （L） and some of the complexes. The conductance data indicate that the complexes of the formulas Na[Au（SCH3CHCOO）2], Na[Au（SCH3CHCOO）（OOCCHCH3SH）2] and [Au（L）]Cl are 1：1 electrolyte. Electronic spectra and magnetic moment values indicate the presence of square planner geometry around Au（III） ions.

KF-Al₂O₃as an Efficient and Recyclable Basic Catalyst for the Synthesis of 4<i>H</i>-Pyran-3-carboxylates and 5-Acetyl-4<i>H</i>-pyrans

KF-Al2O3 as a recyclable basic catalyst for the three-component synthesis of 4H-pyran derivatives by the reaction of aldehydes, malononitrile and active methylene dicarbonyl compounds in ethanol at room temperature is described. The protocol is environmentally benign and offers rapid access to a wide array of 4H-pyran heterocycles in good to excellent yields.

Synthesis, Reactions and Characterization of 1,1’-(1,4-Phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(ethan-1-one)

Reaction of 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile) (1) with methyl iodide afforded the 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-(methylthio)nicotinonitrile) (2). The reaction of 2 with hydrazine hydrate followed by diazotization reaction af-forded the 1,1’-(1,4-phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(e-than-1-one) (3) and 1,1’-(1,4-phenylenebis(3-(chlorodiazenyl)-6-methyl-1H-pyrazolo[3,4-b]-pyridine-4,5-diyl))bis(ethan-1-one) (4) respectively. On the other hand, reaction of 4 with malononitrile, 2-cyanoethanethioamide, ethyl acetoacetate, acetyl acetone, ethyl benzoylacetate, diethylmalonate, ethyl cyanoacetate and phenacylbromide aiming to build up pyrazolotriazine or pyrazole ring on the ring system of 4. Structures of all newly synthesized heterocyclic compounds in the present study were confirmed by considering the data of IR, 1H NMR, mass spectra as well as that of elemental analyses.

Efficient and mild cyclization procedures for the synthesis of novel 2-amino-4H-pyran derivatives with potential antitumor activity

A series of novel 2-amino-4H-pyran derivatives have been synthesized via a three-component reaction of α,β-unsaturated ketone derivatives, malononitrile, aldehydes in excellent yields, using DBU as a catalyst and ethanol as a cheap, safe, and environmentally benign solvent under mild conditions. Their antitumor activity was evaluated in three human tumor cell lines, including human colon cancer （HCT116）, human cervical cancer （Hela）. and non-small cell lung cancer （H1975）.

Synthesis and Crystal Structure of 9-(2-Hydroxy-5-nitrophenyl)-9H-dibenzo[c,h]-2,7,10-trioxanthene-1,8-dione DMF Solvate

The title compound 9-（2-hydroxy-5-nitrophenyl）-9H-dibenzo[c,h]-2,7,10-trioxan-thene-1,8-dione DMF solvate （C28H20N2O9,Mr=528.46） was synthesized and crystallized.The crystal belongs to the triclinic system,space group P1 with a=10.210（3）,b=10.698（4）,c=12.522（4）,α=92.214（6）,β=113.751（5）,γ=105.040（5）°,Z=2,V=1193.0（7）3,Dc=1.471 g·cm-3,μ（MoKα）=0.112 mm-1,F（000）=548,R=0.0444 and wR=0.1141 for 2667 observed reflections （I 〉 2σ（I））.X-ray analysis reveals that atoms C（1）,C（2）,C（3）,C（4）,C（5） and O（1） on the new 4H-pyran ring are slightly distorted,forming a half-chair conformation.

A cesium fluoride promoted efficient and rapid multicomponent synthesis of functionalized 2-amino-3-cyano-4H-pyran and spirooxindole derivatives

A rapid, one-pot and highly efficient protocol for the synthesis of pharmaceutically interesting functionalized 2-amino-3-cyano-4H-pyran and spirooxindole derivatives has been developed using commercially available Cs F as a catalyst in the reaction of malononitrile and aryl aldehydes or isatins with 1,3-cyclohexanediones. The major advantages of this methodology are excellent yield at ambient temperature, very short reaction time（5–10 min）, and use of an inexpensive catalyst.

Cetyltrimethylammonium chloride(CTAC)catalyzed one-pot synthesis of novel coumarin-4H-pyran conjugates in aqueous media

Novel fluorescent coumarin-4H-pyran conjugates were achieved by three-component reactions of various synthetic β-ketoesters with aldehydes and malononitrile in aqueous media.Besides mild reaction conditions,operational simplicity,absence of tedious separation procedures,using of inexpensive and nontoxic commercially available cationic surfactant cetyltrimethylammonium chloride（CTAC） as a catalyst are the prominent advantage of this method.

SnCl_2/nano SiO_2: A green and reusable heterogeneous catalyst for the synthesis of polyfunctionalized 4H-pyrans

A highly efficient and general method for the synthesis of polyfunctionalized 4H-pyrans is established through a one-pot multicomponent cyclocondensation of aromatic aldehydes with CH acids, malononitrile and ethyl acetoacetate using nano silica supported tin （II） chloride as a catalyst. In this method SnCl2/nano Si02 was used as green and reusable catalyst. Excellent yields, short reaction times, simple workup, and inexpensiveness and commercially availability of the catalyst are the advantages of this method.

Monolayers Langmuir-Blodgett Films of Synthetic Artificial Mimic Molecules That Resemble the Following Tetraether Lipids on Silicon Wafers

This study investigated the behavior and molecular organization of synthetic artificial mimic molecules that resemble the following tetraether lipids: di-O-hexadecyl-glycero-3-phosphatidyl-glycerol (DHGPG) and bis-4-dodecylphenyl-12-phosphate. These molecules were analyzed using Langmuir film balance, ellipsometry and atomic force microscopy. The monolayer Langmuir-Blodgett films of DHGPG and bis-4-dodecylphenyl-12-phosphate were stable on the solid surface silicon wafers. The ellipsometry and AFM results showed that monolayers Langmuir-Blodgett films of DHGPG and bis-4-dodecylphenyl-12-phosphate were present, and the thickness of the observed films varied from 1.2 - 5.0 nm.

Synthesis of 2（5H）-Furanone Derivatives with Bis-1,2,3-triazole Structure

A series of new chiral 2（5H）-furanone derivatives containing bis-l,2,3-triazole moiety were designed and syn- thesized from （5S）-5-alkoxy-3,4-dihalo-2（5H）-furanones 1, dicarboxyl amino acids 2, propargyl bromide, and or- ganic azides 5 under mild conditions via the sequential three steps, including asymmetric Michael addi- tion-elimination, substitution and no-ligand click reaction. Twelve new intermediates, including N-[5-alkoxy- 2（5H）-furanonyl] dicarboxyl amino acids 3 and their corresponding propargyl esters 4, and twelve target molecules 6 were characterized by FTIR, 1H NMR, 13C NMR, MS and elemental analysis. The influences of different syn- thetic conditions and substrates in each step were investigated. The research provides a new method and idea for the synthesis of 2（5H）-furanone compounds with polyheterocyclic structure due to the diversities of four basic unit molecules.

Michael-Addition Reaction of Malononitrile with a,β-Unsaturated Cycloketones Catalyzed by KF/Al_2O_3

A series of KF/Al2O3 catalyzed Michael-addition reactions between malononitrile and a,b-unsaturated cycloke-tones in DMF solution were studied. At room temperature, 2-cyano-3-aryl-3-(1,2,3,4-tetrahydronaphthalen- 1-one-2-yl) propionitrile derivatives were synthesized by the reaction between 2-arylmethylidene-1,2,3,4-tetra-hydronaphthalen-1-one and malononitrile. However, if the temperature was increased to 80 ℃, 2-amino-3-cyano-4- aryl-4H-benzo[h]chromene derivatives were obtained in high yields. When the a,b-unsaturated ketones were re-placed by 2,6-biarylmethylidenecyclohexanone or 2,5-biarylmethylidenecyclopentanone, another series of 2-amino- 3-cyano-4H-pyran derivatives was isolated successfully. The structures of the products were confirmed by X-ray diffraction analysis.

A luminescence molecular switch via modulation of PET and ICT processes in DCM system

A novel versatile dicyanomethylene-4H-pyran （DCM） based derivative bearing ferrocenyl group （DCM-N-Fc） is designed as modulator to construct ＂off-on＂ logic operation. The optical properties of DCM-N-Fc are characterized by absorption and steady-state fluorescence technique, showing that the fluorescence from DCM ehromophore via intramolecular charge transfer （ICT） is strongly quenched by photoinduced electron transfer （PET） process from ferrocene moiety. In contrast with the references （DCM-N and DCM-Fc）, the fluorescence of DCM-N-Fc can be triggered by oxidizing ferrocenyl unit either chemically or electrochemically, exhibiting a characteristic emission modulation at around 610 nm with an electrofluorochromic behavior. Furthermore, the free energy and the fluorescence lifetime in the PET path verify the thermodynamic feasibility. Cyclic voltammetry, absorption spectroscopy, time-resolved fluorescence as well as DFT calculation have been used to elaborate the manipulation via both PET and ICT processes.

Enhancement of open circuit voltage in organic solar cells by doping a fluorescent red dye

The open circuit voltage （Voc） of small- molecule organic solar cells （OSCs） could be improved by doping suitable fluorescent dyes into the donor layers. In this paper, 4-（dicyanomethylene）-2-t-butyl-6-（1,1,7,7- tetramethyljulolidyl-9-enyl）-4H-pyran （DCJTB） was used as a dopant, and the performance of the OSCs with different DCJTB concentration in copper phthalocyanine （CuPc） was studied. The results showed that the Voc of the OSC with 50% of DCJTB in CuPc increased by 15%, compared with that of the standard CuPc/fullerene （C60） device. The enhancement of the Voc was attributed to the lower highest occupied molecular orbital （HOMO） level in the DCJTB than that in the CuPc. Also, the light absorption intensity is enhanced between 400 and 550nm, where CuPc and C6o have low absorbance, leading to a broad absorption spectrum.