Molbank — Open Access Journal

Abstract: A gold(I) complex with a triphenylphosphine and a monodentate N,N-dimethyldithiocarbamate ligand was synthesized and characterized by Raman spectroscopy and single crystal X-ray diffraction. DFT calculations (Gaussian 09, PBE1PBE/Lanl2dz) were undertaken for a single complex in the gas phase. The DFT-optimized structure and calculated Raman spectrum are in good agreement with the crystal structure and the experimental spectrum. Assignments of the Raman peaks are based on these DFT calculations. Frontier molecular orbitals were calculated and their nature is discussed. Full article

Structures containing 8-hydroxyquinoline scaffold are useful for anticancer drug development. The title ester (5-chloroquinolin-8-yl)-2-fluorobenzoate was prepared by the reaction of 2-fluorobenzoyl chloride with 5-chloro-8-hydroxyquinoline. The structure of the title compound was assigned by diverse spectroscopic techniques. Moreover, a crystallographic study was undertaken and its supramolecular characteristics were analyzed. Thus, the central ester fragment C8/O1/C10(O2)/C11 is almost planar with a root mean square (r.m.s.) deviation of 0.0612 Å and it makes dihedral angles of 76.35(6)° and 12.89(11)°, with quinoline and phenyl rings respectively. The structure shows C–H...X (X = halogen) non-classical hydrogen bonds. It also has a halogen…halogen distance less than the sum of the van der Waals radii (3.2171(15) Å). As a result of interactions with halogen atoms, chains of centrosymmetric dimer that form edge-fused R²₂(18) rings run parallel to the plane (100). Full article

A Friedel-Crafts–type ring-opening/intramolecular Michael addition cascade reaction of (E)-4-(3-(dimethylamino)phenyl)but-3-en-2-one with dimethyl 2-phenylcyclopropane-1,1-dicarbo-xylate catalyzed by Yb(OTf)₃ has produced a new compound, dimethyl 7-(dimethylamino)-3,4-dihydro-1-(2-oxopropyl)-4-phenylnaphthalene-2,2(1H)-dicarboxylate. This reaction provided diastereoslective trans tetralin (7:3 dr) on the cyclohexyl ring. The structure of the newly synthesized compound was determined using ¹H-, ¹³C-NMR, IR and mass spectral data. Full article

Title compound was designed to be a black quencher of pyrene fluorescence. It was made amphiphilic to serve as a membrane-bound probe. The synthesis is a two-step procedure. The first step is a Mitsunobu reaction of [{(phenyldiazenyl)phenyl}diazenyl]phenol with 1,2-O-isopropylideneglycerol. The second step is the cleavage of the isopropylidene protecting group. The title compound has the extinction coefficient 59,000 at λmax = 380 nm. The Forster distance between the title compound and the pyrene was found to be 37.8 Å. Full article

The copper complex of 5,10,15,20-tetrakis-(3,4-dibenzyloxyphenyl)porphyrin (CuTDBOPP) was synthesized and characterized with electronic absorption spectroscopy and ESI high-resolution spectrometry. In the electronic spectrum, there was a shift in the Soret band from 424 nm to 420 nm that indicated that the insertion of the metal ion was successful. Additionally, the number of Q bands decreased from four peaks to a single peak at 541 nm. The molar absorptivity of the Soret and Q band are 3.4 × 10⁵ cm⁻¹·M⁻¹ and 1.8 × 10⁵ cm⁻¹·M⁻¹, respectively. The ESI HRMS was in excellent agreement with simulated isotopic distribution spectra. CuTDBOPP was incorporated into a series of Gratzel cells where the open current voltage was recorded. Full article

The two geometric isomers of 2-(tert-butyl)-4-phenyloxetane have, for the first time, been prepared starting from the commercially available 4,4-dimethyl-1-phenylpentane-1,3-dione. The latter was reduced with NaBH₄ to give a mixture of diastereomeric syn and anti diols which were then stereospecifically cyclized into the corresponding oxetanes with an overall yield for the two steps of 69.6%. The newly synthesized stereoisomeric four-membered oxygenated heterocycles were separated by column chromatography on silica gel and fully spectroscopically characterized. Full article

The synthesis of 1H-benzo[f]isoindole derivatives was achieved by the cascade radical cyclization–cyclization reaction of the active methine substrate having an allyl group and phenyl group as different two radical acceptors. This oxidative transformation proceeded by using iron(III) chloride FeCl₃ as a mild oxidant via the intramolecular radical addition to the allyl group followed by the second radical addition to the phenyl group. Full article

N-Vinylpirrolidinone reacts with (E)-ethyl 5-hydroxy-3-(4-oxo-4H-chromen-3-yl) acrylate (1) through a domino reaction similar to that reported reaction for ethyl vinyl ether. Inverse electron demand Diels–Alder (IEDDA)–elimination-IEDDA generates isomeric tetracycles 5 and 6. The assignment of the relative stereochemistry of the products was made by comparing the proton couplings with those obtained by reaction with ethyl vinyl ether. Full article

The title compound, (Z)-4-(carbomethoxymethylene)-2-(4-fluorophenyl)-4H-benzo[d][1,3]oxazine, was synthesized in 68% isolated yield by palladium-catalyzed oxidative cyclization-methoxycarbonylation of 4-fluoro-N-(2-((trimethylsilyl)ethynyl)phenyl)benzamide. This new heterocyclic derivative was fully characterized by IR, ¹H-NMR, ¹³C-NMR spectroscopies, MS spectrometry, and elemental analysis. The Z configuration around the double bond was unequivocally established by 2D NOESY experiments. Full article

Ethyl({[acryloyl(furan-2-ylmethyl)amino]acetyl}amino)acetate was synthesized via Ugi four component (4C) reaction at ambient temperature. The protocol employs a reaction between formaldehyde, furfurylamine, acrylic acid, and ethyl 2-isocyanoacetate. The course of the reaction was found to be high yielding, and the resulting glycine ester derivative was well characterized by elemental analysis, FTIR, NMR spectroscopy, and mass spectrometric techniques. Full article

The title chalcone (E)-1-(2-aminophenyl)-3-(benzo[d][1,3]dioxol-5-yl)prop-2-en-1-one was obtained in 76% yield from a NaOH catalyzed Claisen–Schmidt condensation reaction between o-aminoacetophenone and piperonal. This product will be used as a key precursor for the development of an alternative route for the total synthesis of the alkaloid Graveoline. Single crystals of the title compound suitable for X-ray diffraction were grown via slow evaporation in ethanol at room temperature. A complete crystallographic study was performed in depth to unequivocally confirm its structure. The crystal structure of the title o-aminochalcone, C₁₆H₁₃NO₃, shows two molecules per asymmetric unit (Z = 4) and adopts an E configuration about the C=C double bond. In the title compound, the mean plane of the non-H atoms of the central chalcone fragment C—C(O)—C—C—C is as follow: [root-mean-square (r.m.s.) deviation = 0.0210 Å for A–B and 0.0493 for C–D molecules]. In the crystal, molecules are linked by N–H...O and C–H...O, hydrogen bonds forming S(6), R²₂(6) and edge-fused R⁴₄(24)rings along with C(18) chains running parallel to (110). Full article

N-[2-(Cyclohexylamino)-2-oxoethyl]-N-(4-octyloxy)phenyl-prop-2-enamide was prepared in good yield by coupling of 4(octyloxy)aniline, Cyclohexyl isocyanide, paraformaldehyde and acrylic acid by multicomponent Ugi reaction, at room temperature. The structure of the newly synthesized tripeptoid derivative was well characterized using elemental analysis, FTIR, NMR and mass spectral data. Full article

An efficient procedure to obtain the new compound 1a from ethyl acetoacetate (2a), NBS and N,N′-diethylthiourea (4a) was reported. In comparison with the traditional method to synthesize its analogues, this efficient, catalyst-free, and one-pot synthetic method is facile. The work-up procedure is easy and gives the pure target compound under milder reaction conditions in a relatively high yield of 75%. Full article