- Tailored Coumarin Dyes for Photoredox Catalysis: Calculation, Synthesis, and Electronic Properties
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High level time-dependent density functional theory (TD-DFT) computational modeling of coumarin dyes has been exploited for guiding the design of effective photocatalysts (PCs). A library of coumarins were investigated from the theoretical point of view and photophysical/electrochemical properties (absorption and emission spectra, E00, oxidation and reduction potentials) were evaluated. Comparison with literature values reported for a few candidates has been used for assessing the level of theory. On the basis of the results obtained, new strongly reducing PCs [Eox(PC.+/PC*)=?2.1 – ?2.0 V vs SCE] were discovered. Through the computational study of structure-properties relationships, a number of coumarins derivatives have been synthesized and evaluated in the pinacol coupling of aldehydes as the model reaction. The new organic photoredox catalysts show experimental photophysical and electrochemical data in accordance with the ones predicted by calculation, with excited state reduction potentials surpassing those of highly reducing transition metal-based PCs. A careful investigation of their behavior as PC has revealed crucial issues that need to be taken into consideration in the general photoredox catalysis, shedding light on the use of these PC in the pinacol, as well as, in other photoredox reactions.
- Gualandi, Andrea,Nenov, Artur,Marchini, Marianna,Rodeghiero, Giacomo,Conti, Irene,Paltanin, Ettore,Balletti, Matteo,Ceroni, Paola,Garavelli, Marco,Cozzi, Pier Giorgio
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p. 981 - 989
(2020/12/07)
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- Photoinduced Iron-Catalyzed ipso-Nitration of Aryl Halides via Single-Electron Transfer
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A photoinduced iron-catalyzed ipso-nitration of aryl halides with KNO2 has been developed, in which aryl iodides, bromides, and some of aryl chlorides are feasible. The mechanism investigations show that the in situ formed iron complex by FeSO4, KNO2, and 1,10-phenanthroline acts as the light-harvesting photocatalyst with a longer lifetime of the excited state, and the reaction undergoes a photoinduced single-electron transfer (SET) process. This work represents an example for the photoinduced iron-catalyzed Ullmann-type couplings.
- Wu, Cunluo,Bian, Qilong,Ding, Tao,Tang, Mingming,Zhang, Wenkai,Xu, Yuanqing,Liu, Baoying,Xu, Hao,Li, Hai-Bei,Fu, Hua
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p. 9561 - 9568
(2021/08/06)
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- Novel carbazole-stilbene hybrids as multifunctional anti-Alzheimer agents
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Molecules capable of engaging with multiple targets associated with pathological condition of Alzheimer's disease have proved to be potential anti-Alzheimer's agents. In our goal to develop multitarget-directed ligands for the treatment of Alzheimer's disease, a novel series of carbazole-based stilbene derivatives were designed by the fusion of carbazole ring with stilbene scaffold. The designed compounds were synthesized and evaluated for their anti-AD activities including cholinesterase inhibition, Aβ aggregation inhibition, antioxidant and metal chelation properties. Amongst them, (E)-1-(4-(2-(9-ethyl-9H-carbazol-3-yl)vinyl)phenyl)-3-(2-(pyrrolidin-1-yl)ethyl)thiourea (50) appeared to be the best candidate with good inhibitory activities against AChE (IC50 value of 2.64 μM) and BuChE (IC50 value of 1.29 μM), and significant inhibition of self-mediated Aβ1–42 aggregation (51.29% at 25 μM concentration). The metal chelation study showed that compound (50) possessed specific copper ion chelating property. Additionally, compound (50) exhibited moderate antioxidant activity. To understand the binding mode of 50, molecular docking studies were performed, and the results indicated strong non-covalent interactions of 50 with the enzymes in the active sites of AChE, BuChE as well as of the Aβ1-42 peptide. Additionally, it showed promising in silico ADMET properties. Putting together, these findings evidently showed compound (50) as a potential multitarget-directed ligand in the course of developing novel anti-AD drugs.
- Chaudhary, Bharat N.,Gandhi, Pallav M.,Joshi, Prashant D.,Kanhed, Ashish M.,Patel, Dushyant V.,Patel, Kirti V.,Patel, Kishan B.,Patel, Nirav R.,Patel, Sagar P.,Prajapati, Navnit K.,Teli, Divya M.,Yadav, Mange Ram
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- Preparation method of methyl p-aminophenylacetate
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An embodiment of the invention provides a preparation method of methyl p-aminophenylacetate and relates to the field of chemical synthesis. According to the preparation method, benzyl cyanide is adopted as a starting material and subjected to nitration, hydrolysis, esterification, reduction and other steps in sequence, and methyl p-aminophenylacetate is obtained with high yield. The preparation method adopts a reasonable route, is simple to operate, does not have quite high requirement for equipment and is suitable for large-scale industrial production, and the raw material is widely sourced.
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Paragraph 0045; 0046; 0047; 0048; 0049; 0050
(2019/01/14)
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- Development and Utilization of a Palladium-Catalyzed Dehydration of Primary Amides to Form Nitriles
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A palladium(II) catalyst, in the presence of Selectfluor, enables the efficient and chemoselective transformation of primary amides into nitriles. The amides can be attached to aromatic rings, heteroaromatic rings, or aliphatic side chains, and the reactions tolerate steric bulk and electronic modification. Dehydration of a peptaibol containing three glutamine groups afforded structure-activity relationships for each glutamine residue. Thus, this dehydration can act similarly to an alanine scan for glutamines via synthetic mutation.
- Al-Huniti, Mohammed H.,Rivera-Chávez, José,Colón, Katsuya L.,Stanley, Jarrod L.,Burdette, Joanna E.,Pearce, Cedric J.,Oberlies, Nicholas H.,Croatt, Mitchell P.
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p. 6046 - 6050
(2018/09/27)
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- Double Dehydrogenation of Primary Amines to Nitriles by a Ruthenium Complex Featuring Pyrazole Functionality
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A ruthenium(II) complex bearing a naphthyridine-functionalized pyrazole ligand catalyzes oxidant-free and acceptorless selective double dehydrogenation of primary amines to nitriles at moderate temperature. The role of the proton-responsive entity on the ligand scaffold is demonstrated by control experiments, including the use of a N-methylated pyrazole analogue. DFT calculations reveal intricate hydride and proton transfers to achieve the overall elimination of 2 equiv of H2.
- Dutta, Indranil,Yadav, Sudhir,Sarbajna, Abir,De, Subhabrata,H?lscher, Markus,Leitner, Walter,Bera, Jitendra K.
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supporting information
p. 8662 - 8666
(2018/07/09)
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- Design and synthesis of a magnetic hierarchical porous organic polymer: A new platform in heterogeneous phase-transfer catalysis
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Recyclable phase transfer catalysts containing magnetic nanoparticles (MNPs) have been known as a major trend towards sustainable catalysts. In this study, a novel class of magnetic porous polymer on the basis of calix[4]resorcinarene was synthesized starting from silica-coated Fe3O4 core-shell nanoparticles. This compound was found as an efficient phase transfer catalyst to the conversion of benzyl halides into benzyl azides and cyanides in good yields. The catalyst could be used at least for five consecutive cycles without appreciable loss in the catalytic activity.
- Mouradzadegun, Arash,Ganjali, Mohammad Reza,Mostafavi, Mahsa Alsadat
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- Preparation method of 4-aminophenylacetic acid medicine intermediate
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The invention provides a preparation method of a 4-aminophenylacetic acid medicine intermediate. The preparation method comprises 1, adding concentrated sulfuric acid, concentrated nitric acid and benzyl cyanide into a reactor, carrying out a reaction process, and carrying out crystallization, filtration, water washing and re-crystallization to obtain 4-nitrophenylacetonitrile, 2, adding a sulfuric acid solution and glacial acetic acid into the 4-nitrophenylacetonitrile, carrying out heating backflow, after the reaction, pouring the reaction mixture into a reactor with ice water so that the product is crystallized and precipitated in the ice water, carrying out suction filtration to obtain white solids, carrying out re-crystallization through distilled water and glacial acetic acid, and drying the crystals to obtain 4-nitrophenylacetic acid, 3, adding 4-nitrophenylacetic acid, ethanol and skeletal nickel into a pressure reactor according to a certain ratio, carrying out a reaction process for some time, carrying out standing cooling to the room temperature, distilling to remove solvent ethanol, cooling the solution for crystallization, filtering the crystals and drying the crystals to obtain crude products, and 4, carrying out re-crystallization on the crude products through ethanol, and carrying out decoloring through active carbon to obtain light white crystals of 4-aminophenylacetic acid. The preparation method has a low cost and less side reactions and is suitable for industrial application.
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Paragraph 0012
(2017/05/10)
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- Benzyltin pyrimidine derivatives, their preparation and their use as medicaments
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The invention relates to the field of pharmaceutical chemistry, specifically to benzyl pyrimidine derivatives (I), preparation methods thereof, medicinal compositions containing the derivatives and medical application of the derivatives, in particular, application of the derivatives as an immunosuppressant in autoimmune diseases and organ transplantation.
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Paragraph 0068; 0069
(2017/01/19)
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- NOVEL PROCESS FOR PREPARATION OF MIRABEGRON AND IT'S INTERMEDIATE
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The present invention related to a novel process for preparation of Mirabegron of formula (I) and its intermediate. I
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Page/Page column 14
(2015/11/10)
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- Design, synthesis and biological evaluation of novel sesquiterpene mustards as potential anticancer agents
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Several novel series of sesquiterpene mustards (SMs) bearing nitrogen mustard and glutathione (GSH)-reactive α-methylene-γ-butyrolactone groups were successfully prepared for the first time and showed excellent antiproliferative activities in vitro. Among them, compounds 2e and 2g displayed the highest antiproliferative properties with IC50 values ranging from 2.5 to 8.7 μM. The selectivity of these two compounds was evaluated by SRB method against human cancer and normal hepatic cells (HepG2 and L02). The induction of apoptosis and effects on the cell cycle distribution with compounds 2e and 2g were investigated by Hoechst 33,258 staining and flow cytometry, which exhibited that they could induce selective cell apoptosis and cell cycle arrest in HepG2 and L02 cells. In addition, further investigation showed that compounds 2e and 2g could obviously inhibit the proliferation of HepG2 cells by inducing significant DNA cross-linking and depleting GSH in cell media. The good cytotoxicity and selectivity of compounds 2e and 2g pointed them as promising leads for anticancer drug design.
- Xu, Yuan-Zhen,Gu, Xue-Yan,Peng, Shou-Jiao,Fang, Jian-Guo,Zhang, Ying-Mei,Huang, De-Jun,Chen, Jian-Jun,Gao, Kun
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p. 284 - 297
(2015/03/30)
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- The Concise Synthesis of Unsymmetric Triarylacetonitriles via Pd-Catalyzed Sequential Arylation: A New Synthetic Approach to Tri- and Tetraarylmethanes
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The selective synthesis of multiarylated acetonitriles via sequential palladium-catalyzed arylations of chloroacetonitrile is reported. The three aryl groups are installed via a Pd-catalyzed Suzuki-Miyaura cross coupling reaction followed by back-to-back C-H arylations to afford triarylacetonitriles in three steps with no over-arylation at any step. The triarylacetonitrile products can be converted into highly functionalized species including tetraarylmethanes. This new strategy provides rapid access to a variety of unsymmetrical tri- and tetraarylmethane derivatives from simple, readily available starting materials. (Chemical Presented)
- Nambo, Masakazu,Yar, Muhammad,Smith, Joel D.,Crudden, Cathleen M.
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supporting information
p. 50 - 53
(2015/07/28)
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- Synthesis, optical and nonlinear optical properties of new pyrazoline derivatives
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We report on synthesis and optical properties of new organic compounds based on substituted pyrazole ring. The investigated pyrazoline derivatives (PRDs) exhibit efficient broadband photoluminescence which covers nearly whole visible spectrum. The experimental results are compared to quantum chemical calculations. Amplified spontaneous emission and photodegradation measurements were performed for hybrid systems based on selected PRDs doped into poly(methyl methacrylate) matrix proving the potential utility of such systems in lasing applications. Two-photon absorption (TPA) properties were characterized by the femtosecond Z-scan technique.
- Mysliwiec,Szukalski,Sznitko,Miniewicz,Haupa,Zygadlo,Matczyszyn,Olesiak-Banska,Samoc
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- The novel usage of thiourea nitrate in aryl nitration
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Thiourea nitrate (TN) was easily prepared from thiourea and nitric acid to explore its use as a new nitration reagent. Nitrations of various aromatic compounds utilizing TN in concentrated sulfuric acid were studied. TN could convert aromatic compounds to the corresponding nitrated derivatives with various abnormal yields under mild conditions. The results suggested that the reaction mechanism might be different from those of traditional nitration reagents.
- Meng, Ge,Zheng, Mei-Lin,Zheng, A-Qun,Wang, Mei,Shi, Juan
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- A large dipole moment to promote gelation for 4-nitrophenylacrylonitrile derivatives with gelation-induced emission enhancement properties
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A series of 4-nitrophenylacrylonitrile and phenylacrylonitrile derivatives consisting of a carbazole moiety was synthesized. Some of these derivatives with longer alkyl chains and a nitro group could gelatinize some organic solvents, such as ethanol, n-butanol, ethyl acetate, and DMSO. By contrast, phenylacrylonitrile derivatives did not form gels in measured solvents. This result proved that the electron-withdrawing nitro moiety was important for gel formation because it conferred the molecules with large dipole moments, which enhanced the intermolecular interaction. Analyses by UV-vis absorption, X-ray diffraction, and scanning electron microscopy showed that the gelator molecules could self-assemble into one-dimensional nanofibers with layer packing, which further twisted into thicker fibers and formed three-dimensional networks in the gel phase. The single crystal structure of C4CNPA implied that the gelators might adopt an anti-parallel molecular stacking because of their larger ground-state dipole moment. Interestingly, the organogels had enhanced fluorescence relative to solutions at the same concentrations. This journal is the Partner Organisations 2014.
- Xue, Pengchong,Yao, Boqi,Zhang, Yuan,Chen, Peng,Li, Kechang,Liu, Baijun,Lu, Ran
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p. 7110 - 7118
(2014/10/16)
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- Metal-free, one-pot oxidative conversion of aldehydes to primary thioamides in aqueous media
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One-pot tandem reactions of a variety of aldehydes with aqueous ammonia, molecular iodine, and O,O-diethyl dithiophosphoric acid readily afford the corresponding primary thioamides. This is an inexpensive, practical, and metal-free way of accessing various thioamides from aldehydes in aqueous media. The pure products are obtained simply by filtration followed by successive washing with aqueous sodium thiosulfate and water. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.]
- Yadav, Arvind K.,Srivastava, Vishnu P.,Yadav, Lal Dhar S.
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supporting information
p. 408 - 416
(2014/01/06)
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- Ionic liquid-induced conversion of methoxymethyl-protected alcohols into nitriles and iodides using [Hmim][NO3]
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This Letter reports a one-pot efficient conversion of methoxymethyl-ethers into their corresponding nitriles and iodides using the ionic liquid, 1-methyl-3H-imidazolium nitrate ([Hmim][NO3]) under microwave irradiation. A variety of products were prepared in high yields using this method.
- Noei, Jalil,Mirjafari, Arsalan
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supporting information
p. 4424 - 4426
(2014/08/05)
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- Synthesis of novel fluorescent 2-{4-[1-(pyridine-2-yl)-1H-pyrazol-3-yl] phenyl}-2H-naphtho [1,2-d] [1,2,3] triazolyl derivatives and evaluation of their thermal and photophysical properties
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Novel 2-{4-[1-(pyridine-2-yl)-1H-pyrazol-3-yl] phenyl}-2H-naphtho [1,2-d] [1,2,3] triazolyl fluorescent derivatives were synthesized from p-nitrophenylacetic acid and 2-hydrazino pyridine through Vilsmeier-Haack and diazotization reactions. Photophysical properties were evaluated, and results show that compounds have good fluorescence quantum yields. Thermal analysis showed that they are reasonably stable. The structures of the compounds were confirmed by FT-IR, 1H NMR, 13C NMR, and mass spectral and elemental analysis.
- Padalkar, Vikas S.,Phatangare, Kiran R.,Sekar
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p. 809 - 813
(2013/08/23)
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- An A-D-A small molecule based on the 3,6-dithienylcarbazole electron donor (D) unit and nitrophenyl acrylonitrile electron acceptor (A) units for solution processed organic solar cells
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A new A-D-A small molecule (SM) based on a 3,6-dithienylcarbazole donor unit at the center and nitrophenyl acrylonitrile acceptor units as the terminal ends was synthesized by the Pd catalyzed Stille coupling reaction for application as a donor material in the organic bulk heterojunction solar cells. The SM possesses a low lying HOMO energy level at -5.34 eV and optical band gap of 1.74 eV. The photovoltaic performance of the SM was investigated with PC 60BM and PC70BM as acceptors cast from THF with 3% CN additive and without additive. The power conversion efficiency (PCE) of the organic solar cells based on SM:PC60BM cast from THF solvent reached 1.94% with a high Voc of 0.94 V, a Jsc of 6.08 mA cm -2 and FF of 0.34, where as the PCE of SM:PC70BM cast from THF solvent was 2.65% with a Voc of 0.96 V, a Jsc of 7.26 mA cm-2 and FF of 0.38%, under the illumination intensity of 100 mW cm-2. The higher PCE of the organic solar cells based on PC 70BM as an electron acceptor has been attributed to its strong absorption in the visible region than PC60BM. The PCE of the organic solar cells has been further improved to 3.76% and 4.96% for SM:PC 60BM and SM:PC70BM, respectively, cast with CN-THF solvent. The Royal Society of Chemistry 2013.
- Singh, Manjeet,Kurchania, Rajnish,Mikroyannidis,Sharma,Sharma
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p. 2297 - 2306
(2013/07/05)
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- A heterogeneous palladium catalyst hybridised with a titanium dioxide photocatalyst for direct C-C bond formation between an aromatic ring and acetonitrile
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A palladium catalyst hybridised with a titanium dioxide photocatalyst can promote cyanomethylation of an aromatic ring by using acetonitrile, where the photocatalyst activates acetonitrile to form a cyanomethyl radical before the C-C bond formation using the palladium catalyst.
- Yoshida, Hisao,Fujimura, Yuki,Yuzawa, Hayato,Kumagai, Jun,Yoshida, Tomoko
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supporting information
p. 3793 - 3795
(2013/05/22)
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- Organic bulk heterojunction solar cells based on solution processable small molecules (A-π-A) featuring 2-(4-nitrophenyl) acrylonitrile acceptors and phthalimide-based π-linkers
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A novel small molecule-based organic donor SM [(2Z,2′Z)-3,3′- (((1E,1′E)-(2-cyclohexyl-1,3-dioxoisoindoline-4,7-diyl)bis(ethene-2, 1-diyl))bis(4,1-phenylene))bis(2-(4-nitrophenyl)-acrylonitrile)] featuring 2-(4-nitrophenyl)acrylonitrile as the acceptor and a π-conjugation bridge composed of phthalimide and styryl units, with an A-π-A type structure, has been synthesized. It showed a long wavelength absorption band having an absorption maximum around 635 nm and the optical bandgap was 1.63 eV, which is lower than most reported conjugated polymers, including poly(3-hexylthiophene) (P3HT). The photovoltaic properties were investigated by constructing bulk heterojunction organic solar cell devices using SM as the electron donor and fullerene derivatives, i.e. PC60BM and PC70BM as the electron acceptors with the device architecture ITO/PEDOT:PSS/SM:PC 60BM or PC70BM/Al. The effect of the SM/fullerene derivative weight ratio and the processing solvent were carefully investigated to improve the performance of the organic solar cells. The optimized organic solar cell with SM:PC60BM and SM:PC70BM cast from THF solvent, at a weight ratio of 1:3 showed power conversion efficiencies (PCEs) of about 1.70% and 2.56%, respectively. The enhanced value of PCE for the BHJ photovoltaic device based on PC70BM is related to the better absorption of PC70BM in the visible region compared to that of PC60BM. The SM:PC70BM blends cast from a DIO-THF mixture and subsequent thermal annealing exhibited improved PCEs of 3.68% and 4.14%, respectively.
- Sharma,Mikroyannidis,Kurchania, Rajnish,Thomas, K. R. Justin
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body text
p. 13986 - 13995
(2012/08/08)
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- Application of β-cyclodextrin-polyurethane as a stationary microvessel and solid-liquid phase-transfer catalyst: Preparation of benzyl cyanides and azides in water
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Application of water tolerant heterogeneous catalyst, β-cyclodextrin- polyurethane (β-CDPU) polymer, as an efficient microvessel and polymeric host system for nucleophilic substitution reaction of benzyl halides with cyanide and azide anions in water has been described. The reactions gave only pure products, which did not require any further purification. The most important features of this method are high yields, clean reactions and that the catalyst can be recovered and recycled.
- Kiasat, Ali Reza,Nazari, Simin
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p. 102 - 105
(2013/01/15)
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- New photosensitizer with phenylenebisthiophene central unit and cyanovinylene 4-nitrophenyl terminal units for dye-sensitized solar cells
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A new low band gap photosensitizer, D, which contains 2,2′-(1,4- phenylene) bisthiophene central unit and cyanovinylene 4-nitrophenyl terminal units at both sides was synthesized. The two carboxyls attached to the 2,5-positions of the phenylene ring act as anchoring groups. Dye D was soluble in common organic solvents, showed long-wavelength absorption maximum at 620-636 nm and optical band gap of 1.72 eV. The electrochemical parameters, i.e. the highest occupied molecular orbital (HOMO) (-5.1 eV) and the lowest unoccupied molecular orbital (LUMO) (-3.3 eV) energy levels of D show that this dye is suitable as molecular sensitizer. The quasi solid state dye-sensitized solar cell (DSSC) based on D shows a short circuit current (Jsc) of 9.95 mA/cm2, an open circuit voltage (Voc) of 0.70 V, and a fill factor (FF) of 0.64 corresponding to an overall power conversion efficiency (PCE) of 4.40% under 100 mW/cm2 irradiation. The overall PCE has been further improved to 5.52% when diphenylphosphinic acid (DPPA) coadsorbent is incorporated into the D solution. This increased PCE has been attributed to the enhancement in the electron lifetime and reduced recombination of injected electrons with the iodide ions present in the electrolyte with the use of DPPA as coadsorbant. The electrochemical impedance spectroscopy (EIS) results indicated that the augment ascribes to inhibited interfacial charge recombination between the conduction band electrons and the tri-iodide ions in the electrolyte.
- Mikroyannidis,Suresh,Roy,Sharma
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experimental part
p. 5616 - 5623
(2011/06/26)
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- Low band gap conjugated small molecules containing benzobisthiadiazole and thienothiadiazole central units: Synthesis and application for bulk heterojunction solar cells
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Two novel conjugated low band gap small molecules (SMs), M1 and M2, containing benzobisthiadiazole and thienothiadiazole central units, respectively, were synthesized. Both SMs carried terminal cyanovinylene 4-nitrophenyl at both sides which were connected to the central unit with a thiophene ring. The long-wavelength absorption band was located at 591-643 nm and the optical band gap was 1.62-1.63 eV, which is lower than that of P3HT. These two SMs were investigated as electron donor materials along with PCBM or F as electron acceptors for fabrication of bulk heterojunction (BHJ) organic photovoltaic devices. F is a modified PCBM which has been previously synthesized and used as an electron acceptor for poly(3-hexylthiophene) (P3HT). The power conversion efficiency (PCE) for M1:PCBM, M1:F, M2:PCBM and M2:F was 1.05%, 2.02%, 1.23% and 2.72%, respectively. The higher PCE for the devices with M2 as the electron donor has been related to the improved hole mobility for M2. However, the improved PCE for the devices with F as the electron acceptor has been attributed to the more intense absorption of F in the visible region than that of PCBM and also to the higher open circuit voltage resulting from the higher LUMO level of F. We have also fabricated devices with M2:F cast film from mixed solvents. The PCE for the BHJ devices with the as cast and thermally annealed M2:F (mixed solvents) is 3.34% and 3.65%, respectively.
- Mikroyannidis,Tsagkournos,Sharma,Vijay,Sharma
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body text
p. 4679 - 4688
(2011/10/13)
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- Low band-gap phenylenevinylene and fluorenevinylene small molecules containing triphenylamine segments: Synthesis and application in bulk heterojunction solar cells
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Starting from triphenylamine, two low band gap small molecules, PH and FL, based on phenylenevinylene and fluorenevinylene, respectively were synthesized. They were soluble in common organic solvents such as tetrahydrofuran, chloroform and dichloromethane. Their long-wavelength absorption maximum was at 605-643 nm with optical band gap of 1.64-1.66 eV. These small molecules showed a band gap lower than that of P3HT and also have deeper HOMO level, which is beneficial for improvement of the open circuit voltage. The photovoltaic properties have been investigated using the bulk heterojunction (BHJ) active layer of PH or FL with PCBM. The device based on FL:PCBM displayed higher power conversion efficiency (PCE) (1.42%) than the device based on PH:PCBM (1.02%), when the blend films were cast from chloroform solvent. Moreover, various casting solvents were used for the BHJ solar cells based on FL:PCBM blend and their effect on the photovoltaic performance was investigated. The results indicate that high boiling point solvents lead to an enhanced self-organization of FL in the active layer, which causes an increased charge transport. Finally, we have used a modified PCBM, i.e. F as electron acceptor along with FL as electron donor, to increase the light harvesting in the wavelength region below 500 nm and the PCE is about 4.38% when the BHJ (FL:F blend) device was spin casted from mixed 1-chloronaphthalene/o-dichlorobenzene solvents. The improved PCE has been attributed to the increased light absorption and higher hole mobility in the active layer, which resulted in more balanced charge transport.
- Mikroyannidis,Kabanakis,Sharma,Sharma
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body text
p. 774 - 784
(2012/03/26)
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- Palladium-catalyzed cyanomethylation of aryl halides through domino Suzuki coupling-isoxazole fragmentation
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A one-pot protocol for the cyanomethylation of aryl halides through a palladium-catalyzed reaction with isoxazole-4-boronic acid pinacol ester was developed. Mechanistically, the reaction proceeds through (1) Suzuki coupling, (2) base-induced fragmentation, and (3) deformylation as shown by characterization of all postulated intermediates. Under optimized conditions (PdCl2dppf, KF, DMSO/H2O, 130 °C) a broad spectrum of aryl bromides could be converted into arylacetonitriles with up to 88% yield.
- Velcicky, Juraj,Soicke, Arne,Steiner, Roland,Schmalz, Hans-Guenther
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supporting information; experimental part
p. 6948 - 6951
(2011/06/19)
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- Ethylammonium nitrate (EAN)/Tf2O and EAN/TFAA: Ionic liquid based systems for aromatic nitration
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Acting as in situ sources of triflyl nitrate (TfONO2) and trifluoroacetyl nitrate (CF3COONO2), the EAN/Tf 2O and EAN/TFAA systems, generated via metathesis in the readily available ethylammonium nitrate (EAN) ionic liquid as solvent, are powerful electrophilic nitrating reagents for a wide variety of aromatic and heteroaromatic compounds. Comparative nitration experiments indicate that EAN/Tf2O is superior to EAN/TFAA for nitration of strongly deactivated systems. Both systems exhibit low substrate selectivity (K T/KB = 5-10) in (Figure presented) between values reported for covalent nitrates and preformed nitronium salts.
- Aridoss, Gopalakrishnan,Laali, Kenneth K.
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experimental part
p. 8088 - 8094
(2011/11/13)
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- Simple sensitizers of low band gap based on 4-nitro-a-cyanostilbene prepared from a one-step reaction for efficient dye-sensitized solar cells
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Two simple dyes D1 and D2 based on 4-nitro-a-cyanostilbene were conveniently synthesized from a one-step reaction. These dyes were prepared from the condensation of 4-carboxybenzaldehyde or 4-hydroxybenzaldehyde with 4-nitrobenzyl cyanide to afford 4-nitro-40-carboxy-a-cyanostilbene (D1) and 4-nitro-40-hydroxy-a-cyanostilbene (D2) respectively. Photophysical and electrochemical properties of the dyes were investigated by UV-vis spectroscopy and cyclic voltammetry. Their absorption spectra were broad with long-wavelength absorption maximum at 617-655 nm and optical band gap of 1.63 eV. These two dyes were used as sensitizers in quasi solid state dye-sensitized solar cells (DSSCs). Photovoltaic devices with D1 showed a maximum monochromatic incident photon to current efficiency (IPCE) of 70% and overall power conversion efficiency (PCE) of 4.8%, under illumination intensity 100 mW/cm2. The photovoltaic performance of the cell with D2 was lower because of less dye loading on the TiO2 surface, since it has OH anchoring group, and lower electron lifetime. Additionally, we have investigated the photovoltaic response of the DSSCs with nitrogen doped TiO2 photoanode and found that the PCE has been enhanced. The enhancement in PCE has been attributed to the increase in open circuit voltage and fill factor.
- Mikroyannidis,Tsagkournos,Balraju,Sharma
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experimental part
p. 1242 - 1249
(2011/10/12)
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- Enhanced performance of bulk heterojunction solar cells using novel alternating phenylenevinylene copolymers of low band gap with cyanovinylene 4-nitrophenyls
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Two novel low band gap soluble copolymers, P1 and P2, were synthesized and characterized. P1 consisted of alternating dihexyloxyphenylene and α-[[4-(diphenylamino) phenyl]methylene]-4-nitro-ben-zeneacetonitrile. P2 consisted of alternating dihexyloxyphenylene and α,α'-[(1,4- phenylene)dimethy-lidyne]bis(αZ,α'Z)-4-nitrobenzeneacetonitrile. These copolymers showed broad absorption curves with long-wavelength absorption maximum around 620 nm and optical band of 1.68 and 1.64 eV for P1 and P2, respectively. Both P1 and P2 were blended with PCBM to study the photovoltaic response of bulk heterojunction (BHJ) solar cells. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of both P1 and P2 are well aligned with those of PCBM acceptor. This allows efficient photoinduced charge transfer and high open circuit voltage, leading to an overall power conversion efficiency (PCE) of 3.15% and 2.60% for the as cast P1:PCBM-and P2:PCBM-based devices, respectively. The PCE of the devices has been further improved up to 4.06% and 3.35% for the devices based on thermally annealed P1:PCBM and P2:PCBM blends, respectively.
- Mikroyannidis,Kabanakis,Balraju,Sharma
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experimental part
p. 5544 - 5553
(2011/10/30)
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- Symmetrical molecules of low band gap with a central spacer connected via ether bond with terminal 4-nitro-α-cyanostilbene units: Synthesis and application for bulk heterojunction solar cells
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Two new soluble and symmetrical molecules M1 and M2 of low band gap with a central spacer which was connected at both sides via ether bond with terminal 4-nitro-α-cyanostilbene units were synthesized. The spacer of M1 and M2 consisted of dihexyloxyphenylene and n-hexylene, respectively. Their long-wavelength absorption maximum was at 590-640 nm. The thin film absorption onset for both molecules was located at 742 nm which corresponds to an optical band gap of 1.67 eV. We have fabricated bulk heterojunction (BHJ) photovoltaic devices using these molecules as donor and PCBM as acceptor. We have investigated the solvent vapor treatment effect of these blends on their morphology and photovoltaic properties. We found that the overall power conversion efficiency (PCE) for the devices based on the solvent vapor treated M1:PCBM and M2:PCBM blends is 3.05% and 1.90%, respectively, higher than those of pristine blends. This increase of PCE has been attributed to the increase in surface roughness of the blend and better balance in charge transport. The PCE has been further increased up to 3.57% and 2.42% with the thermally annealed solvent treated M1:PCBM and M2:PCBM blend, respectively. This increase of PCE may be attributed to the enhanced crystallinity of the blend and reduction of the space charge effect, improving the charge transport and collection efficiency.
- Mikroyannidis,Kabanakis,Sharma,Kumar, Anil,Sharma
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experimental part
p. 1631 - 1641
(2011/12/02)
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- Microwave-promoted, one-pot conversion of alkoxymethylated protected alcohols into their corresponding nitriles, bromides, and iodides using [bmim][InCl4] as a green catalyst
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The Lewis acid room temperature ionic liquid, [bmim][InCl4], was found to be an efficient and green catalyst for the highly chemoselective and one-pot conversion of MOM- or EOM-ethers into their corresponding nitriles, bromides, and iodides under microwave irradiation. The procedures are simple, rapid, and high yielding. The catalyst exhibited a remarkable reactivity and is reusable.
- Mirjafari, Arsalan,Mohammadpoor-Baltork, Iraj,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Khosropour, Ahmad Reza
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supporting information; experimental part
p. 3274 - 3276
(2010/07/18)
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- A novel practical cleavage of tert-butyl esters and carbonates using fluorinated alcohols
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Thermolytic cleavage of t-butyl esters and t-butyl carbonates was accomplished using TFE (2,2,2-trifluoroethanol) or HFIP (hexafluoroisopropanol) as solvent. Thus, a practical method to cleanly convert t-butyl esters and carbonates into the corresponding carboxylic acids, decarboxylated products, or alcohols in nearly quantitative yields was developed. The product is recovered by a simple solvent evaporation. The practicality of this methodology was demonstrated on alkyl, aryl, and heteroaromatic esters.
- Choy, Jason,Jaime-Figueroa, Saul,Lara-Jaime, Teresa
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experimental part
p. 2244 - 2246
(2010/05/18)
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- DEPROTECTION OF BOC-PROTECTED COMPOUNDS
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Organic compounds having t-butyl ester or BOC carbonate protecting groups are effectively deprotected by heating in a fluorinated alcohol solution.
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Page/Page column 3
(2010/12/29)
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- Synthesis, analgesic and anti-inflammatory activities of novel 3-(4-acetamido-benzyl)-5-substituted-1,2,4-oxadiazoles
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A series of 3-(4-acetamido-benzyl)-5-substituted-1,2,4-oxadiazoles (7a-7n) were synthesized and screened for analgesic and in vivo anti-inflammatory activities using acetic acid writhing in mice model and carrageenan-induced paw oedema method in mice, respectively. The analgesic activity of compounds 7i and 7m is superior while that of 7d, 7c, 7f and 7j is equal to the reference standard, diclofenac sodium. The anti-inflammatory activity of compounds 6, 7c, 7e, 7f, 7i, 7l, 7m and 7n is found to be superior than that of diclofenac sodium which is used as a reference, while compounds 7d and 7g are found to be equipotent with the reference compound.
- Farooqui, Mazahar,Bora, Rajesh,Patil
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scheme or table
p. 794 - 799
(2009/09/08)
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- Substituted 3-((Z)-2-(4-nitrophenyl)-2-(1H-tetrazol-5-yl) vinyl)-4H-chromen-4-ones as novel anti-MRSA agents: Synthesis, SAR, and in-vitro assessment
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In search for a new antibacterial agent with improved antimicrobial spectrum and potency, we designed and synthesized a series of novel 3-((Z)-2-(4-nitrophenyl)-2-(1H-tetrazol-5-yl) vinyl)-4H-chromen-4-ones 7a-h by convergent synthesis approach. All the synthesized compounds were assayed for their in-vitro antibacterial activities against gram-negative and gram-positive bacteria.
- Diwakar, Santosh D.,Bhagwat, Sachin S.,Shingare, Murlidhar S.,Gill, Charansing H.
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scheme or table
p. 4678 - 4681
(2009/04/08)
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- Synthesis of 3,5-disubstituted [1,2,4]-oxadiazoles
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Substituted amidoximes have been synthesized, and converted to corresponding oxadiazoles as a novel heterocyclic compounds under mild conditions in good to excellent yield.
- Bora, Rajesh O.,Farooqui, Mazahar
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scheme or table
p. 569 - 573
(2009/07/18)
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- An efficient one-step method for the conversion of β-(dimethylamino) styrenes into arylacetonitriles
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A new simple and efficient one-step method for the preparation of arylacetonitriles by reaction of β-(dimethylamino)styrenes with hydroxylamine hydrochloride in formic acid solution is described. Georg Thieme Verlag Stuttgart.
- Starosotnikov, Alexey M.,Lobach, Alexander V.,Shevelev, Svyatoslav A.
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p. 2830 - 2832
(2007/10/03)
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- Mild palladium-catalyzed selective monoarylation of nitriles
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Two new palladium-catalyzed procedures for the arylation of nitriles under less basic conditions than previously reported have been developed. The selective monoarylation of acetonitrile and primary nitriles has been achieved using α-silyl nitriles in the presence of ZnF2. This procedure is compatible with a variety of functional groups, including cyano, keto, nitro, and ester groups, on the aryl bromide. The arylation of secondary nitriles occurred in high yield by conducting reactions with zinc cyanoalkyl reagents. These reaction conditions tolerated base-sensitive functional groups, such as ketones and esters. The combination of these two methods, one with a-silyl nitriles and one with zinc cyanoalkyl reagents, provides a catalytic route to a variety of benzylic nitriles, which have not only biological significance but utility as synthetic intermediates. The utility of these new coupling reactions has been demonstrated by a synthesis of verapamil, a clinically used drug for the treatment of heart disease, by a three-step route from commercial materials that allows convenient variation of the aryl group.
- Wu, Lingyun,Hartwig, John F.
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p. 15824 - 15832
(2007/10/03)
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- Efficient conversion of tetrahydropyranyl (THP) ethers to their corresponding cyanides with triphenylphosphine/2,3-dichloro-5,6- dicyanobenzoquinone/n-Bu4 NCN
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Tetrahydropyranyl ethers were converted to their corresponding alkyl cyanides efficiently by using the triphenylphosphine/ 2,3-dichloro-5,6- dicyanobenoquinone / n-Bu4 NCN system in refluxing acetonitrile with good-to-excellent yields.
- Akhlaghinia, Batool
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p. 1783 - 1786
(2007/10/03)
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- Clay supported ammonium nitrate "clayan": A new reagent for selective nitration of arenes
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The nitration of activated, deactivated and highly functionalized arenes is described using clay-supported ammonium nitrate in the presence of perchloric acid.
- Meshram,Ganesh,Madhavi,Eshwaraiah,Yadav,Gunasekar
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p. 2497 - 2503
(2007/10/03)
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- Base-mediated reaction of quaternary ammonium salts with nitroarenes - Their useful functionalization via vicarious nucleophilic substitution (VNS)
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Ammonium ylides generated from ammonium salt 1a-e with a base react with derivatives of 3-nitropyridine 2a-c and 2-nitrothiophene (3) to form products of vicarious nucleophilic substitution (VNS) 7, 8, or 9 respectively. The products of VNS 10, 11, or 12 are also produced from the corresponding ammonium salts, a base and 4-chloro-nitrobenzene (4), nitrobenzene (5), or 1-nitronaphthalene (6), respectively. In a few products, an exchange of alkoxy group 7c or substitution of chlorine by alkoxyl 8a,b occured.
- Jonczyk, Andrzej,Kowalkowska, Anna
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p. 674 - 680
(2007/10/03)
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- A fast and mild method for the nitration of aromatic rings
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The use of N2O5 and a Fe(III) catalyst for the nitration of aromatic rings is described. This methodology is compatible with most functional groups and results in near quantitative yields in 4 min. The reaction conditions are non-oxidising: benzaldehyde and benzyl alcohols are readily nitrated with little or no oxidation (4%) occurring. The addition of the iron catalyst activates the system to such an extent that nitration of an activated aromatic ring, such as toluene, occurs quantitatively at -100°C. This high activity allows compounds with sensitive functional groups such as alkenes to be smoothly nitrated.
- Bak, Radoslaw R.,Smallridge, Andrew J.
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p. 6767 - 6769
(2007/10/03)
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- High-temperature rearrangements of 2-acylisoxazol-5(2H)-ones and related oxazoles
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2-Acyl-3-arylisoxazol-5(2H)-ones give 2-alkyl(aryl)-4-aryloxazoles in good yields at 540°C under flash vacuum pyrolysis conditions, but at higher temperatures the expected oxazoles are accompanied by increasing amounts of isomeric 2,5-disubstituted oxazoles, as well as anilides and decomposition products of the 2,4-disubstituted oxazole. The rearrangement mechanisms have been studied by the use of 13C labelled substrates and p-substituted 3-arylisoxazolones. The 2,5-disubstituted oxazoles are considered to arise from 1H-azirines, and the anilides from the nitrone ketene isomer of the acylisoxazolone.
- Clark, Adrian D.,Ha, Uyen T.,Prager, Rolf H.,Smith, Jason A.
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p. 1029 - 1033
(2007/10/03)
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- Benzylimidazolines as h5-HT(1B/1D) serotonin receptor ligands: A structure-affinity investigation
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Benzylimidazolines may represent a class of 5-HT(1D) ligands that has yet to be exploited. On the basis of a previous report that the 2- (substituted-benzyl)imidazoline α-adrenergic agonist oxymetazoline (8) binds with high affinity at calf brain 5-HT(1D) receptors, we explored the structure-affinity relationships of a series of related derivatives. Each of the aromatic substituents was removed and then reinstated in a systematic manner to determine the influence of the individual substituents on binding. It was found that all of the aromatic substituents of 8 act in concert to impart high affinity. However, although the 3-hydroxy group could be removed without significantly reducing affinity for h5-HT(1D) (i.e., human 5- HT(1Dα)) receptors, this modification reduced h5-HT(1B) (i.e., human 5- HT(1Dβ)) receptor affinity by nearly 50-fold. The 2,6-dimethyl groups also contribute to binding but seem to play a greater role for h5-HT(1B) binding than h5-HT(1D) binding. With the appropriate structural modifications, several compounds were identified that display 20- to > 100-fold selectivity for h5-HT(1D) versus h5-HT(1B) receptors. Preliminary functional data suggest that these compounds behave as agonists. Given that 5-HT(1D) agonists are currently being explored for their antimigraine action and that activation of h5-HT(1B) receptors might be associated with cardiovascular side effects, h5- HT(1D)selective agents may offer a new lead for the development of therapeutically efficacious agents.
- Law, Ho,Dukat, Malgorzata,Teitler, Milt,Lee, David K. H.,Mazzocco, Lucia,Kamboj, Raj,Rampersad, Vik,Prisinzano, Thomas,Glennon, Richard A.
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p. 2243 - 2251
(2007/10/03)
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- Thermal Isomerizations of Substituted Benzyl Isocyanides: Relative Rates Controlled Entirely by Differences in Entropies of Activation
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The absolute and relative rates of thermal rearrangments of substituted benzyl isocyanides were obtained at the temperatures between 170 and 230 °C. The relative rates are independent of temperature and exhibit excellent Hammett correlations (p+ = -0.24). The temperature studies yielded activation parameters (ΔHY? and ΔSY?) and their differential counterparts (ΔΔHY-H? and ΔΔSY-H?). The differential terms were plotted against σ+. The secondary α-deuterium kinetic isotope effects (kD/kH = 1.11) were measured at several temperatures. The rate data can be rationalized with the cyclic TS. The substituent effects on the rates are due to the entropic contributions.
- Kim, Sung Soo,Choi, Won Jung,Zhu, Yu,Kim, Jin Hyun
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p. 1185 - 1189
(2007/10/03)
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- Carboanion Reactivity: Kinetics of the Reactions of Benzyl Cyanide Anions with Aromatic Nitro-compounds
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Rate and equilibrium measurements are reported for the reactions in methanol of carbanions derived from 12 ring-substituted benzyl cyanides with 1,3,5-trinitrobenzene to give ?-adducts.Some data for reaction of the carbanions with 4-nitrobenzofuroxan were also measured.With increasing carbanion reactivity, rate constants approach a limit of just below 109 dm3 mol-1 s-1.Intrinsic reactivities of carbanions in ?-adduct forming reactions and in proton transfer reactions are compared.
- Atherton, John H.,Crampton, Michael R.,Duffield, Gaynor L.,Stevens, J. Andrew
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p. 443 - 448
(2007/10/02)
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- Substituted phenyl sulfonamides as selective β 3 agonists for the treatment of diabetes and obesity
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Substituted phenylsulfonamides are selective β 3 adrenergic receptor agonists with very little β 1 and β 2 adrenergic receptor activity and as such the compounds are capable of increasing lipolysis and energy expenditure in cells. The compounds thus have potent activity in the treatment of Type II diabetes and obesity. The compounds can also be used to lower triglyceride levels and cholesterol levels or raise high density lipoprotein levels or to decrease gut motility. In addition, the compounds can be used to reduced neurogenic inflammation or as antidepressant agents. The compounds are prepared by coupling an aminoalkylphenyl-sulfonamide with an appropriately substituted alkyl epoxide. Compositions and methods for the use of the compounds in the treatment of diabetes and obesity and for lowering triglyceride levels and cholesterol levels or raising high density lipoprotein levels or for increasing gut motility are also disclosed.
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- Proton transfer from carbon acids to carbanions. 1. Reactions of various carbon acids with the anions of substituted benzylmalononitriles in 90% Me2SO-10% water. determination of intrinsic barriers of identity reactions from the marcus relationship
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A kinetic study of the reversible deprotonation of 9-cyanofluorene (2), 1,3-indandione (3), 4-nitrophenyl-acetonitrile (4), (3-nitrophenyl)nitromethane (5), and (4-nitrophenyl)nitromethane (6) by the anions of substituted benzylmalononitrile (1-X-) in 90% Me2SO-10% water (v/v) at 20 °C is reported. Intrinsic rate constants and intrinsic barriers of these reactions have been determined by extrapolation or interpolation of Br?nsted plots whose slopes (β) are all close to 0.5. Intrinsic barriers of the identity reactions CH + C- ? C- + CH (CH = 2,3,4,and phenylnitromethane) have been estimated on the basis of the Marcus equation, coupled with either a plausible value for the identity barrier of the reaction AH+ + A ? A + AH+ (A = piperidine or morpholine) ("amine method") or a plausible value for the identity barrier of the reaction 2 + 2- ? 2- + 2 ("9-cyanofluorene method"). There are discrepancies in the identity barriers for CH + C- ? C- + CH (CH = 2, 3, 4, and phenylnitromethane) calculated by the two methods. Possible reasons for these discrepancies and the significance of the results in terms of the validity and scope of the Marcus equation are discussed.
- Bernasconi, Claude F.,Ni, Jiu Xiang
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p. 5060 - 5066
(2007/10/02)
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- Intrinsic Reactivities of Some Carbanions in ?-Adduct Forming Reactions
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Kinetic and equilibrium data are reported for nucleophilic attack in methanol at unsubstituted ringpositions of 1,3,5-trinitrobenzene, 2,4,6-trinitrotoluene and 1-chloro-2,4,6-trinitrobenzene by carbanions derived from dimethyl malonate, ethyl cyanoacetate and 4-nitro-, 4-cyano- and 2-cyanobenzyl cyanides.The results are used to determine intrinsic reactivities for the carbanions in these ?-adduct forming reactions and are discussed in terms of the electronic and solvent reorganisation occurring during reaction.
- Crampton, Michael R.,Stevens, Andrew J.
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p. 1715 - 1720
(2007/10/02)
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- CRYPTATE ACIDITY SCALES. V. EQUILIBRIUM ACIDITY OF INDICATOR CH-ACIDS IN TETRAHYDROFURAN
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A scale of equilibrium cryptate acidity in tetrahydrofuran is constructed.Its distinguishing feature is the constancy of the contribution from ionic association.A method is proposed for determination of the constants for the association of the ions into ion pairs in dimethyl sulfoxide.
- Antipin, I. S.,Gareev, R. F.,Vedernikov, A. N.,Konovalov, A. I.
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p. 1039 - 1044
(2007/10/02)
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