- Fluorenone Schiff base derivative complexes of ruthenium, rhodium and iridium exhibiting efficient antibacterial activity and DNA-binding affinity
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Metal precursors [(arene)MCl2]2 (arene = p-cymene, Cp?; M = Ru, Rh and Ir) on reacting with 9-fluorenone derivative ligands L1, L2 and L3 resulted in the formation of mononuclear bidentate cationic N∩N bonded complexes. The biological studies of these complexes such as antibacterial activity studies (against Gram-positive and Gram-negative bacteria) revealed significant antibacterial activity with complexes 4, 7 and 9 having the highest activity potency (in-vitro). Whilst for DNA-binding studies, the results revealed that complexes 4 and 5 displayed significant changes in their spectral features upon addition of SM-DNA, thus, indicating that these complexes bind to DNA with a significant affinity.
- Agarwal, Nipanshu,Banothu, Venkanna,Kaminsky, Werner,Kollipara, Mohan Rao,Poluri, Krishna Mohan,Shadap, Lathewdeipor
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- The Electrochemical Reduction of Fluorenone Tosylhydrazone: Evidence Consistent with Formation of the Tosyl Nitrene Anion Radical
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Fluorenone tosylhydrazone (Fl=NNHTs) undergoes one-electron reductive dehydrogenation in DMF-0.1 F (n-Bu)4NClO4 to give hydrogen and its conjugate base Fl=NN-Ts as products.Fl=NN-Ts is subsequently reduced at more negative potential to a dianion radical (Fl=NNTs dianion radical) that is stable on the cyclic voltammetric time scale.On the coulometric time scale or in the presence of added proton donors (pKa ca.29), Fl=NNTs dianion radical decomposes to give FlHNH2 and TsNH2 as the principal products.A pathway is proposed for the reaction of Fl=NNTs dianion radical which involves rate-determining proton abstraction by the nitrogen atom α to the fluorene moiety.Cyclic voltammetric and chronoamperometric data are presented which are consistent with the formation of the tosyl nitrene anion radical as a short-lived, unobserved intermediate.
- Galen, Dean A. Van,Barnes, James H.,Hawley, M. Dale
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- INTERMEDIATES IN THE DECOMPOSITION OF ALIPHATIC DIAZO-COMPOUNDS. PART 20. KINETIC STUDIES ON REDUCTIVELY INITIATED ELECTRON TRANSFER CHAIN CATALYSIS OF THE DECOMPOSITION OF 9-DIAZOFLUORENE
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The method of constant-current electrolysis (c.c.e.) at a platinum cathode has been used to investigate the kinetics of the electron transfer chain catalysis of the decomposition of 9-diazofluorene (FlN2) in CH3CN solution.Equations have been derived for various possible kinetic forms of both chain propagation and termination, and comparision with observation indicates that the chain carrier reacts with a molecule of FlN2 to propagate the chain and reacts with the solvent, or other additive such as oxygen or diethyl malonate, to terminate the chain.Interruption of the current in the experiments (i.c.c.e.) leads to a different set of equations from which it is possible to evaluate separately the rate constants for propagation and termination.The identity of the chain carrier is discussed.It is established that this is unlikely to be the diazoalkane anion radical, FlN2(-.), as previously thought.Anion-radicals derived from the product fluorenone azine are the likeliest candidates under the reaction conditions used.
- Bethell, Donald,McDowall, Linda J.,Parker, Vernon D.
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- Experimental and Computational Studies on Stepwise [3+2]-Cycloadditions of Diaryldiazomethanes with Electron-Deficient Dimethyl (E)- and (Z)-2,3-Dicyanobutenedioates
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Electron-deficient dimethyl (E)- and (Z)-2,3-dicyanobutenedioates (dimethyl dicyanofumarate and dicyanomaleate, respectively) react with diaryldiazomethanes at room temperature under spontaneous evolution of N2. The type of the products strongly depends on the structure of the diazo compound. Whereas diphenyldiazomethane and its bis(4-methoxy) derivative yield cyclopropanes, sterically crowded 5-diazo-5H-dibenzo[a,d]cycloheptane derivatives afford either the dimer of the carbene formed via N2 elimination or the adduct of the carbene onto the starting diazo compound. The course of the studied reactions is rationalized by stepwise mechanisms initiated by the formation of a C–N bond. A cascade of reactions leads to the corresponding cyclopropanes or to release of a carbene species. The formation of a pyrazole via [3+2]-cycloaddition (32CA) is observed only in reactions with (trimethylsilyl)diazomethane, which behaves similar to the parent diazomethane. The proposed mechanisms were analyzed computationally using the DFT method.
- Mlostoń, Grzegorz,Celeda, Ma?gorzata,Jasiński, Radomir,Heimgartner, Heinz
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- The decomposition of diazo-compounds induced by nucleophiles. The decomposition of 9-diazofluorene in the presence of hydroxide or alkoxide ions
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9-Diazofluorene, on treatment with stoichiometric or substoichiometric amounts of quaternary ammonium hydroxide or methoxide or of potassium t-butoxide in solution in aqueous or alcoholic dimethyl sulfoxide or acetonitrile at 30°C, decomposes with evolution of nitrogen to yield fluorenone azine [bis(fluorenylidene)hydrazine] in almost quantitative yield. Studies are reported of the identity of the minor by-products, together with an examination of the kinetics of the reactions and additional spectroscopic experiments. The general rate equation is v = k[FIN2]3/2[Nu-]1/2, where Nu- represents the nucleophile. It is concluded that the oxyanions, most probably after nucleophilic attack on 9-diazofluorene under these basic conditions to generate a new anionic species, are capable of transferring an electron to the diazo-compound. This initiates decomposition of further diazo-molecules in a process of electron-transfer chain catalysis that bears some similarities to, but has also some differences from, that encountered using cathodic initiation. In support of this interpretation it is found that reactions can be accelerated by the introduction of carbon acids (fluorene, 9-phenylfluorene) into the reaction mixtures. The nature of the initiation, propagation and termination steps of the chain mechanism are discussed.
- McDowell, Linda J.,Khodaei, M. Mehdi,Bethell, Donald
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- Tuning the rotation rate of light-driven molecular motors
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Overcrowded alkenes are among the most promising artificial molecular motors because of their ability to undergo repetitive light-driven unidirectional rotary motion around the central C=C bond. The exceptional features of these molecules render them highly useful for a number of applications in nanotechnology. Many of these applications, however, would benefit from higher rotation rates. To this end, a new molecular motor was designed, and the isomerization processes were studied in detail. The new motor comprises a fluorene lower half and a five-membered-ring upper half; the upper-half ring is fused to a p-xylyl moiety and bears a tert-butyl group at the stereogenic center. The kinetics of the thermal isomerization was studied by low-temperature UV-vis spectroscopy as well as by transient absorption spectroscopy at room temperature. These studies revealed that the tert-butyl and p-xylyl groups in the five-membered-ring upper half may be introduced simultaneously in the molecular design to achieve an acceleration of the rotation rate of the molecular motor that is larger than the acceleration obtained by using either one of the two groups individually. Furthermore, the new molecular motor retains unidirectional rotation while showing remarkably high photostationary states.
- Bauer, Jurica,Hou, Lili,Kistemaker, Jos C. M.,Feringa, Ben L.
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- A Schiff-based fluorescence sensor for the detection of Cu2+ and its application in living cells
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A novel fluorescent and colorimetric probe FL was designed and synthesized for selective Cu2+ detection in aqueous solutions. The detection limit of probe FL for Cu2+ was determined to be 1.09 μM. Furthermore, probe FL was successfully used to recognize Cu2+ in living cells, indicating its high potential in biological imaging applications.
- Chiou, Yi-Ru,Yan, Hongbin,Wan, Chin‐Feng,Yen Huang, Chi,Wu, An-Tai
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- Electrochemical Studies of the Reduction of Fluorenone Triphenylphosphazine. Formation of the Stable Dimeric Dianion, (FlN2)2(2-)
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The electrochemical reduction of fluorenone triphenylphosphazine (Fl=NN=PPh3) in N,N-dimethylformamide - 0.1 M (n-Bu)4NClO4 is initially a one-electron process which affords the corresponding anion radical.Fl=NN=PPh3(-*) is unstable on the cyclic voltammetric time scale, decomposing by nitrogen-phosphorus bond cleavage (k = 0.45 s-1 at T = 1 deg C) to give PPh3 and 9-diazofluorene anion radical (FlN2(-*)).The latter species then reacts rapidly with either FL=NN=PPh3 or FlN2(-*) to give a stable dimeric dianion.The dianion, which was shown from chronoamperometric and coulometric gas-pressure studies to have the empirical formula (FlN2)2(2-), is oxidized in successive one-electron steps to (FlN2)2 which slowly loses N2 on the cyclic voltammetric time scale to give fluorenone azine (Fl=NN=Fl).The structure of the dimeric species is considered to be the tetraazatriene Fl=NN=NN=Fl.No evidence was obtained for the formation of the carbene anion radical, Fl(-*), via the loss of N2 from FlN2(-*).
- Herbranson, Dale E.,Theisen, F. J.,Hawley, M. Dale,McDonald, Richard N.
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- Mechanochromism, Twisted/Folded Structure Determination, and Derivatization of (N-Phenylfluorenylidene)acridane
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(N-Phenylfluorenylidene)acridane (Ph-FA) compounds with electron-withdrawing and -donating substituents (H, MeO, Ph, NO2, Br, F) at the para position of the phenyl group were successfully synthesized by Barton–Kellogg reactions of N-aryl thioacridones and diazofluorene. By using the substituent on the nitrogen atom to alter the electronic properties, both the folded and twisted conformers of p-NO2-C6H4-FA could be crystallographically characterized, which enabled the charge transfer from the electron-donating acridane moiety to the electron-accepting fluorenylidene moiety to be understood. Ground-state mechanochromism, thermochromism, vapochromism, and proton-induced chromism were demonstrated between the folded and twisted conformations of the conformers. Protonation and chemical oxidation of Ph-FA gave two stable acridinium compounds, namely, the fluorenylacridinium and acridinium radical cations. The present study will contribute to the development of functional dyes and organic semiconductors.
- Matsuo, Yutaka,Wang, Ya,Ueno, Hiroshi,Nakagawa, Takafumi,Okada, Hiroshi
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supporting information
p. 8762 - 8767
(2019/05/29)
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- Reactions of hydrazones and hydrazides with Lewis acidic boranes
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The reaction of (diphenylmethylene)hydrazone or 1,4-bis-hydrazone-ylidene(phenylmethyl)benzene with Lewis acidic boranes B(2,4,6-F3C6H2)3 or B(3,4,5-F3C6H2)3 generates the Lewis acid-base adducts. Alternatively, when (9H-fluoren-9-ylidene)hydrazone is employed several products were isolated including 1,2-di(9H-fluoren-9-ylidene)hydrazone, the 2:1 borane adduct of NH2-NH2 and the 1-(diarylboraneyl)-2-(9H-fluoren-9-ylidene)hydrazone in which one ArH group has been eliminated. The benzhydrazide starting material also initially gives an adduct when reacted with Lewis acidic boranes which upon heating eliminates ArH generating a CON2B heterocycle.
- Gazis, Theodore A.,Dasgupta, Ayan,Hill, Michael S.,Rawson, Jeremy M.,Wirth, Thomas,Melen, Rebecca L.
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supporting information
p. 12391 - 12395
(2019/08/26)
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- Nickel-catalyzed synthesis of 9-monoalkylated fluorenes from 9-fluorenone hydrazone and alcohols
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A practical protocol was disclosed for the nickel-catalyzed C-alkylation of 9-fluorenone hydrazone with alcohols using t-BuOK as the base, and 9-monoalkylated fluorene derivatives were obtained in good yields under the benign conditions.
- Fan, Jiang-Tao,Fan, Xin-Heng,Chen, Yong-Jie,Gao, Cai-Yan,Yang, Lian-Ming
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supporting information
p. 2895 - 2902
(2019/08/12)
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- Trifluoromethylation and Monofluoroalkenylation of Alkenes through Radical–Radical Cross-Coupling
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The first visible-light-induced trifluoromethylation and monofluoroalkenylation of simple alkenes via a challenging radical–radical cross-coupling step was achieved. This method provided a mild, step-economical and redox-neutral route to privileged two different fluorinated difunctionalized allyl compounds. The utility of this method is illustrated by late-stage modification of medically important molecules.
- Wang, Qiang,Qu, Yi,Tian, Hao,Liu, Yuxiu,Song, Hongjian,Wang, Qingmin
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supporting information
p. 8686 - 8690
(2019/06/17)
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- INHIBITORS OF MTOR-DEPTOR INTERACTIONS AND METHODS OF USE THEREOF
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Provided herein are substituted hydrazone compounds useful as inhibitors of DEPTOR. The invention further provides pharmaceutical compositions of the compounds of the invention. The invention also provides medical uses of substituted hydrazone compounds.
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(2018/05/24)
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- POLYMERIZABLE COMPOUND AND OPTICAL ISOMER
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The present invention provides a polymerizable compound having high storage stability without causing crystal precipitation when added to a polymerizable composition. The present invention also provides a polymerizable composition containing the compound. When the filmy polymer produced through polymerization of the polymerizable composition is irradiated with UV light, it hardly discolors or peels from substrate. Further, the present invention provides a polymer produced through polymerization of the polymerizable composition and an optically anisotropic body using the polymer.
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Paragraph 0170
(2018/04/02)
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- Efficient synthesis of ferrocifens and other ferrocenyl-substituted ethylenes: Via a 'sulfur approach'
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Stable and non-odorous alkyl ferrocenyl thioketones react with bis(4-methoxyphenyl)diazomethane according to the 'two-fold extrusion' reaction principles, and tetrasubstituted ethylenes obtained thereby can be demethylated to give (Fc,2OH)-ferrocifens in good yields. The method offers an alternative approach to this class of medically relevant compounds. A similar protocol with alkyl ferrocenyl thioketones and selected diaryldiazomethanes leads to ferrocenyl-substituted ethylenes including dibenzofulvenes. These products are of potential interest for electrochemical and photophysical studies.
- Mlostoń, Grzegorz,Hamera-Fa?dyga, Róza,Celeda, Ma?gorzata,Heimgartner, Heinz
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p. 4350 - 4356
(2018/06/21)
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- Structure-activity relationship study of small molecule inhibitors of the DEPTOR-mTOR interaction
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DEPTOR is a 48 kDa protein that binds to mTOR and inhibits this kinase within mTORC1 and mTORC2 complexes. Over-expression of DEPTOR specifically occurs in the multiple myeloma (MM) tumor model and DEPTOR knockdown is cytotoxic to MM cells, suggesting it is a potential therapeutic target. Since mTORC1 paralysis protects MM cells against DEPTOR knockdown, it indicates that the protein–protein interaction between DEPTOR and mTOR is key to MM viability vs death. In a previous study, we used a yeast two-hybrid screen of a small inhibitor library to identify a compound that inhibited DEPTOR/mTOR binding in yeast. This therapeutic (compound B) also prevented DEPTOR/mTOR binding in MM cells and was selectively cytotoxic to MM cells. We now present a structure–activity relationship (SAR) study around this compound as a follow-up report of this previous work. This study has led to the discovery of five new leads – namely compounds 3g, 3k, 4d, 4e and 4g – all of which have anti-myeloma cytotoxic properties superior to compound B. Due to their targeting of DEPTOR, these compounds activate mTORC1 and selectively induce MM cell apoptosis and cell cycle arrest.
- Lee, Jihye,Shi, Yijiang,Vega, Mario,Yang, Yonghui,Gera, Joseph,Jung, Michael E.,Lichtenstein, Alan
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p. 4714 - 4724
(2017/09/29)
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- Fluorenyl salicylaldehyde buzane derivative and preparation method and application thereof
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The invention relates to the technical field of biological chemistry detection, in particular to a fluorenyl salicylaldehyde buzane derivative and a preparation method and application thereof. The compound can freely get in and out of cells and be specifically enriched at the lipid droplet positions in cells, is free of fluorescence originally and now has strong fluorescence, meanwhile, large Stokes shift is displayed under the effect of excited state intramolecular proton transfer, yellow, orange red or red fluorescence is displayed, no displacement exists basically compared with solid fluorescence outside the living body, and the probe localization position can be accurately judged, so that the cell lipid droplet, behavior and physiological process are monitored. The derivative has an extremely wide application prospect in the fields of biology, medical treatment, health and energy.
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Paragraph 0065; 0066; 0067
(2017/04/11)
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- AIE LUMINOGENS FOR VISUALIZATION AND TREATMENT OF CANCER
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The present subject matter relates to AIE luminogens for visualization and treatment of cancer, particularly AIE luminogenic probes for cancer cell visualization and discrimination, lysosome-targeting AIEgens for imaging and autophagy visualization, highly fluorescent AIE-active theranostic agents for monitoring drug distribution and having anti-tumor activity to specific cancer cells, probes comprising AIE luminogens for cancer cell imaging and staining, AIE luminogens having clusteroluminogenic features and applications thereof, and methods of preparing thereof.
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Paragraph 158; 159; 165; 166
(2017/01/09)
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- Synthesis of Cyclic Azomethine Imines by Cycloaddition Reactions of N-Isocyanates and N-Isothiocyanates
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Various nitrogen-substituted iso(thio)cyanates engage in [3 + 2]-cycloaddition reactions to form azomethine imines containing triazolone, triazole-thione, and pyrazole-thione cores. First, iminoisothiocyanates are shown to undergo aminothiocarbonylation reactions with strained alkenes, and a comparison with recently reported reactions of iminoisocyanates highlights their reduced reactivity. In contrast, amino(thio)carbonylation reactions of imines with iminoisocyanates and iminoisothiocyanates proved more efficient, providing access to triazolone and triazole-thione cores. The dipole products can be converted to valuable heterocyclic cores through simple derivatization reactions.
- Bongers, Amanda,Ranasinghe, Indee,Lemire, Philippe,Perozzo, Alyssa,Vincent-Rocan, Jean-Fran?ois,Beauchemin, André M.
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p. 3778 - 3781
(2016/08/16)
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- AZASULFURYLPEPTIDE-BASED CD36 MODULATORS AND USES THEREOF
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Novel azasulfuryl-containing peptidomimetics capable of inhibiting CD36 activity are disclosed. Use of these azasulfuryl-containing peptidomimetics for the treatment of CD36-related diseases, disorders or conditions, including TLR2-mediated inflammatory disease, disorder or condition, and methods of obtaining such azasulfuryl-containing peptidomimetics, are also disclosed.
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Page/Page column 29
(2016/03/22)
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- Hypervalent-iodine(iii) oxidation of hydrazones to diazo compounds and one-pot nickel(ii)-catalyzed cyclopropanation
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A one-pot process for the catalytic cyclopropanation of various alkenes with unsubstituted hydrazones is described. Iodosobenzene (Ph = O) was found to be a competent oxidant of hydrazones to diazo compounds. Ni(OH)2 was chosen as an effective and cheap metal catalyst. The cyclopropane products can be generated efficiently (5 min-4 h) in moderate to good yields (42-91%) under mild (80°C) and neat conditions.
- Liu, Haixuan,Wei, Yunyang,Cai, Chun
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supporting information
p. 674 - 678
(2016/01/12)
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- New applications of hetaryl thioketones for the synthesis of hetaryl-substituted ethenes via 'two-fold extrusion reaction'
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A series of aryl/hetaryl thioketones was applied for the reactions with aryl/hetaryldiazomethanes yielding, after elimination of N2, the corresponding thiiranes. The relatively unstable dihetaryldiazomethanes were generated in situ from the corresponding hydrazones by oxidation with DMSO. The obtained thiiranes were converted into tetraaryl/hetaryl-substituted ethenes in good yields by desulfurization performed with tris(diethylamino)phosphine ((Et2N)3P).
- Mlostoń, Grzegorz,Urbaniak, Katarzyna,Pawlak, Aneta,Heimgartner, Heinz
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p. 127 - 139
(2017/03/14)
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- Facile Synthesis of Isoindolinones via Rh(III)-Catalyzed One-Pot Reaction of Benzamides, Ketones, and Hydrazines
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A Rh(III)-catalyzed one-pot reaction of benzamides, ketones, and hydrazines for facile access to isoindolinones is reported. In this method, various ketones are transformed into donor-donor diazo compounds, which sequentially engage in insertion with benzamides under Rh(III) catalysis to generate N-substituted quaternary isoindolinones. (Chemical Presented).
- Zhang, Yan,Wang, Dahai,Cui, Sunliang
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supporting information
p. 2494 - 2497
(2015/05/27)
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- gem-Difluoroolefination of Diazo Compounds with TMSCF3 or TMSCF2Br: Transition-Metal-Free Cross-Coupling of Two Carbene Precursors
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A new olefination protocol for transition-metal-free cross-coupling of two carbene fragments arising from two different sources, namely, a nonfluorinated carbene fragment resulting from a diazo compound and a difluorocarbene fragment derived from Ruppert-Prakash reagent (TMSCF3) or TMSCF2Br, has been developed. This gem-difluoroolefination proceeds through the direct nucleophilic addition of diazo compounds to difluorocarbene followed by elimination of N2. Compared to previously reported Cu-catalyzed gem-difluoroolefination of diazo compounds with TMSCF3, which possesses a narrow substrate scope due to a demanding requirement on the reactivity of diazo compounds and in-situ-generated CuCF3, this transition-metal-free protocol affords a general and efficient approach to various disubstituted 1,1-difluoroalkenes, including difluoroacrylates, diaryldifluoroolefins, as well as arylalkyldifluoroolefins. In view of the ready availability of diazo compounds and difluorocarbene reagents and versatile transformations of 1,1-difluoroalkenes, this new gem-difluoroolefination method is expected to find wide applications in organic synthesis.
- Hu, Mingyou,Ni, Chuanfa,Li, Lingchun,Han, Yongxin,Hu, Jinbo
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supporting information
p. 14496 - 14501
(2015/11/27)
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- Synthesis of hydrazine and azapeptide derivatives by alkylation of carbazates and semicarbazones
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Hydrazine and azapeptide analogs were synthesized effectively by alkylation of alkylidene carbazates and semicarbazones. In comparisons of benzylidene, benzhydrylidene, and fluorenylidene tert-butyl carbazates in alkylations using bases of different pKb character, superior conversion was obtained using the fluorenone derivative. Mild alkylation conditions were found employing Et4NOH as base and used to convert fluorenylidene tert-butyl carbazate into 13 different protected hydrazines. Moreover, racemization was avoided during alkylation of fluorenylidene semicarbazide in the synthesis of aza-propargylglycinylphenylalanine tert-butyl ester, the protecting groups from which could be selectively removed.
- Garcia-Ramos, Yesica,Proulx, Caroline,Lubell, William D.
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p. 985 - 993
(2013/02/22)
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- Synthesis of dihydroindolizines for potential photoinduced work function alteration
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Seeking to immobilize photochromophores on metallic surfaces, we have synthesized four molecules which contain both a photoresponsive dihydroindolizine (DHI) core and a sulfur containing moiety, which allow for their assembly onto gold substrates. Sonogashira, Suzuki, or Ullmann couplings are employed to generate pyridines with pendant thioacetates (or disulfides). The pyridines are condensed with spiro[2-cyclopropene-1, 9′-[9H]fluorene]- 2, 3-dimethyl ester affording the targeted DHIs.
- Bartucci, Matthew A.,Wierzbicki, Patrycja M.,Gwengo, Chengeto,Shajan, Sunny,Hussain, Syed H.,Ciszek, Jacob W.
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supporting information; experimental part
p. 6839 - 6842
(2011/03/18)
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- Azine-based dimeric charge transport materials
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Improved organophotoreceptor comprises an electrically conductive substrate and a photoconductive element on the electrically conductive substrate, the photoconductive element comprising: (a) a charge transport material having the formula 1 where R1, R2, R3, and R4 comprise, each independently, an alkyl group, an alkenyl group, an aromatic group, a heterocyclic group, or a part of a ring group; X and X′ comprise, each independently, an aromatic group; Y and Y′ comprise, each independently, a (disubstituted)methylene group; and Z is a linking group; (b) a charge generating compound; and (c) an electrically conductive substrate on which said charge transport material and said charge generating compound are located. Corresponding electrophotographic apparatuses and imaging methods are also described.
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- Synthesis and Properties of 9-(Tropylidenehydrazono)fluorene and Related Compounds
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9-(Tropylidenehydrazono)fluorene (1) was obtained by a reaction between 9-fluorenone hydrazone and tropylium tetrafluoroborate. ccompanied by 9-fluorenone azine, 9-(benzylidenehydrazono)fluorene, and 9,9-ditropylfluorene. The amination of 1 occurred at the 2-position of the tropylidene moiety. The addition of tosyl isocyanate to 1 gave the [8 +2] cycloadduct at the 2,4,6-cydoheptatrien-1-imine structure.
- Minabe, Masahiro,Nozawa, Toshiya,Kurose, Tomoko,Kimura, Takao,Tsubota, Motohiro
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p. 693 - 697
(2007/10/03)
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- Characterization of 9-(p-Substituted Benzylidenehydrazono)fluorenes
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The title azine was obtained by a reaction of the corresponding fluorenone hydrazone and p-substituted benzaldehyde. The hydrazone formed from the unsymmetrical fluorenone afforded configurational isomers; the E-isomer was thermodynamically more stable than the Z-isomer. The structure of the title azines, derived from symmetrical fluorenone, was assigned to be (s-translE) form. The azines from unsymmetrical fluorenone gave isomeric mixtures due to the 9-iminofluorene moiety. The electronic spectra of these azines show an intramolecular charge transfer; the red shift beyond 250 nm is observed in the case of 9-[p-(diethylamino)benzylidenehydrazono]-2,4,7-trinitrofluorene, compared to the mother azine. 9-[p-(Pentyloxy)benzylidenehydrazono]-2,7-dinitrofluorene and some of the homologs possess a liquid-crystalline property; the phase-transition temperature of the dinitro compound is K (172 °C) M1 (185)M2 (187) I between the crystalline and liquid phases.
- Minabe, Masahiro,Takabayashi, Yutaka,Setta, Yuji,Nakamura, Hidenao,Kimura, Takao,Tsubota, Motohiro
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p. 3633 - 3638
(2007/10/03)
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- ADENOSINE DERIVATIVES, THEIR METHODS OF PREPARATION AND PHARMACEUTICAL COMPOSITIONS IN WHICH THEY ARE PRESENT
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The present invention relates to the derivatives of the formula STR1 and the corresponding enantiomers and diastereoisomers and, if appropriate, their addition salts, and to their use in therapeutics, especially in the central nervous system as analgesics, anticonvulsants, antiepileptics, anxiolytics, antidepressants and neuroprotectors, and in the cardiovascular system as antiarrhythmics, antihypertensives and platelet aggregation inhibitors.
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- Organic Reactive Intermediates: Part IX-Radical Ions as Reactive Intermediates in Redox Reactions of Triphenylphosphazines
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Two representative phosphazines namely, fluorenylidenetriphenylphosphazine (1) and diphenylmethylenetriphenylphosphazine (2) are shown to undergo oxidation and reduction involving single electron transfer to yield the corresponding cation and anion radicals, respectively.These ion radicals are unstable and decompose to give rise to a blend of other intermediates.Those which act almost certainly as principal intermediates in oxidation and reduction are carbenes and diazoalkane radical anions respectively.
- Handoo, Kishan L.,Gadru, Kanchan
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p. 412 - 417
(2007/10/02)
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- Reactivity of Carbenes and Related Compounds towards Molecular Nitrogen
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The thermal N2 exchange of a number of 15N-labelled diazo compounds was studied in solution.The compounds involved were 3-diazo-1-methylindolin-2-one (1), 9-diazafluorene (2), 5-diazo-1,3-cyclopentadiene-1,2,3,4-tetracarbonitrile (3), 2-diazo-2H-imidazole-4,5-dicarbonitrile (4), 4-diazocyclohexa-2,5-dienone (5), and the conjugate acids of 4 and 5, namely 4,5-dicyano-1H-imidazole-2-diazonium ion (6) and 4-hydroxybenzenediazonium ion (7).Only 1, 4, 6, and 7 exchange their diazo group with 'external' molecular N2.The results are explained on the hypothesis that only organic species which have an empty ? orbital and which are effective in ? electron back-donation are able to react with N2.Thus, reaction with carbenes is likely to occur only if the carbene is in the 1A2 singlet state and if its electrophilicity is high.
- Grieve, Duncan M. A.,Lewis, Graham E.,Ravenscroft, Michael D.,Skrabal, Peter,Sonoda, Takaaki,et al.
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p. 1427 - 1443
(2007/10/02)
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- Hypovalent Radicals. Chemical Trapping of Electrogenerated Diazoalkane Anion Radicals
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Diazoalkane anion radicals produced by electroreduction of diazodiphenylmethane (Ph2CN2) and 9-diazofluorene (FlN2) in the presence of certain proton donors yield the corresponding hydrazones (R2C=NNH2); formation of diphenylmethane from electroreduction of Ph2CN2 is shown to proceed by formation of the carbene anion radical Ph2C*-.
- Triebe, F. M.,Hawley, M. Dale,McDonald, Richard N.
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p. 574 - 575
(2007/10/02)
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