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151.
J. Alberto Guevara-Salazar Delia Quintana-Zavala Hugo A. Jiménez-Vázquez José Trujillo-Ferrara 《Monatshefte für Chemie / Chemical Monthly》2011,10(1):827-836
Abstract
We have carried out the synthesis and characterization of some hexahydroisoindolyl benzoic acids and their corresponding ethyl esters by a multicomponent reaction (MCR) between aminobenzoic acids or aminobenzoates, maleic anhydride, and isoprene in the absence of catalysts. According to additional experiments, the MCR takes place by sequential formation of N-arylmaleamic acids from the aminobenzoic acids or aminobenzoates and maleic anhydride, Diels–Alder adducts of the acids and isoprene, and finally the imides. The 1H NMR data (coupling constants) of the adducts suggested that the preferred conformation of the corresponding cyclohexene rings is a syn-boat, a fact supported by a density functional theory (DFT) conformational analysis and DFT calculations of the spin–spin coupling constants of the corresponding conformers. Our MCR synthetic methodology was tested successfully in the synthesis of other adducts, for which cyclopentadiene and other anilines were employed. 相似文献152.
Adrian Woiczechowski-Pop Delia Gligor Attila Bende Codruta Varodi Elena Bogdan Anamaria Terec 《Supramolecular chemistry》2013,25(1-2):52-58
The synthesis and the structure of a new cryptand with 1,3,5-triphenylbenzene caps and pyridine rings in the chains are reported. The formation of a host–guest assembly between the investigated cryptand and pyrene was predicted by molecular modelling and confirmed by the electrochemical investigations by cyclic voltammetry using graphite electrodes. 相似文献
153.
154.
Heterometallic Complexes with Gold(I) Metalloligands: Self‐Assembly of Helical Dimers Stabilized by Weak Intermolecular Interactions and Solvophobic Effects
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Dr. Verónica Cámara Dr. Natalia Barquero Dr. Delia Bautista Dr. Juan Gil‐Rubio Prof. Dr. José Vicente 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(5):1992-2002
New gold(I) alkynyl metalloligands bpylC?CAuL, bpyl′C?CAuPPh3, and PPN[Au(C?Cbpyl′)2] (bpyl or bpyl′=2,2′‐bipyridin‐5‐yl or ?4‐yl, respectively; L=PMexPh3?x (x=1–3), P(C6H3Me2‐3,5)3, PCy3, XyNC) have been synthesized. Ligands bpylC?CH and metalloligands bpylC?CAuL (L=PPh3, PMePh2, PCy3, CNXy) react with MX2 (M=Fe, Zn, X=ClO4; M=Co, X=BF4) to give complexes [M(bpylC?CZ)3]X2 (Z=H or AuL). In most cases, these complexes are mixtures of fac and mer isomers in a statistical distribution, in both CH2Cl2 and MeCN. However, for L=PPh3, the fac isomer is dominant in MeCN. NMR and ESI‐MS studies, together with the crystal structure of [Co(bpylC?CAuPPh3)3](BF4)2, suggest that this solvent dependence is originated by the formation of helical dimers between two fac complexes in MeCN. These dimers are stabilized by solvophobic effects and multiple intermolecular interactions. Complex [Fe(Ph3PAuC?CbpdiylC?CAuPPh3)3](ClO4)2 (bpdiyl=2,2′‐bipyridin‐5,5′‐diyl) was obtained by reaction of three diauro diethynylbipyridines and Fe(ClO4)2. 相似文献
155.
Jan Stanek Loren B. Andreas Kristaps Jaudzems Diane Cala Daniela Lalli Andrea Bertarello Tobias Schubeis Inara Akopjana Svetlana Kotelovica Kaspars Tars Andrea Pica Serena Leone Delia Picone Zhi‐Qiang Xu Nicholas E. Dixon Denis Martinez Mlanie Berbon Nadia El Mammeri Abdelmajid Noubhani Sven Saupe Birgit Habenstein Antoine Loquet Guido Pintacuda 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(50):15730-15735
156.
Didem Giray Dilgin Delia Gligor H. İsmet Gökçel Zekerya Dursun Yusuf Dilgin 《Mikrochimica acta》2011,173(3-4):469-476
A new approach is described for the photoelectrocatalytic oxidation of Reduced ß-Nicotinamide Adenine Dinucleotide (NADH). It is based on a glassy carbon electrode (GCE) modified with a film of poly-Neutral Red (poly-NR) that is obtained by electropolymerization. Electrochemical measurements revealed that the modified electrode displays electrocatalytic and photo-electrocatalytic activity towards oxidation of NADH. If irradiated with a 250-W halogen lamp, the electrode yields a strongly increased electrocatalytic current compared to the current without irradiation. Amperometric and photo-amperometric detection of NADH was performed at +150 mV vs. Ag/AgCl/KClsat and the currents obtained are linearly related to the concentration of NADH. Linear calibration plots are obtained in the concentration range from 1.0 μM to 1.0 mM for both methods. However, the slope of the current-NADH concentration curve of the photo-electrocatalytic procedure was 2-times better than that obtained without irradiation. Figure
A poly-Neutral Red modified glassy carbon electrode (poly-NR/GCE) was prepared by electropolymerization process. This modified electrode displays electrocatalytic and also photoelectrocatalytic activity towards oxidation of NADH. Compared with electrocatalytic oxidation of NADH, the current response was increased about 2.0 times in the photoelectrocatalytic oxidation process. 相似文献
157.
Millán A Campaña AG Bazdi B Miguel D de Cienfuegos LA Echavarren AM Cuerva JM 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(14):3985-3994
The allylation, crotylation and prenylation of aldehydes and ketones with stable and easily handled allylic carbonates is promoted by a Ti/Pd catalytic system. This Ti/Pd bimetallic system is especially convenient for the allylation of ketones, which are infrequent substrates in other related protocols, and can be carried out intramolecularly to yield five- and six-membered cyclic products with good stereoselectivities. In addition, Ti/Pd-mediated reductions and Würtz-type dimerisation reactions can be readily carried out from allyl carbonates and carboxylates. 相似文献
158.
A reliability system subject to shocks producing damage and failure is considered. The source of shocks producing failures is governed by a Markovian arrival process. All the shocks produce deterioration and some of them failures, which can be repairable or non-repairable. Repair times are governed by a phase-type distribution. The number of deteriorating shocks that the system can stand is fixed. After a fatal failure the system is replaced by another identical one. For this model the availability, the reliability, and the rate of occurrence of the different types of failures are calculated. It is shown that this model extends other previously published in the literature. 相似文献
159.
160.