- A new multitalented azine ligand: Elastic bending, single-crystal-to-single-crystal transformation and a fluorescence turn-on Al(III) sensor
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We report a rare combination of two unique properties of an azine based ligand (H3L): in a solid-state crystalline material it shows highly flexible and elastic behavior which on triggering with light results in slight deviation with phase tran
- Saini, Anoop Kumar,Natarajan, Kaushik,Mobin, Shaikh M.
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- Traceless Isoprenylation of Aldehydes via N-Boc-N-(1,1-dimethylallyl)hydrazones
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A short isoprenylation protocol starting from non-conjugated N-Boc-N-(1,1-dimethylallyl)hydrazones was developed utilising Thomson's traceless bond construction. This type of [3,3]-sigmatropic rearrangement is catalysed by the Br?nsted acid triflimide and liberates only gaseous by-products. The required N-Boc-N-allylhydrazine precursor is available in three steps starting from a known diazene using biocatalytic aldol addition and Tebbe olefination as key steps. Allylhydrazones are prepared via condensation with appropriate aldehydes. Scope and limitations of the [3,3]-sigmatropic rearrangements are analysed.
- Heerdegen, Desirée,Junker, Julia,Dittrich, Sebastian,Mayer, Peter,Bracher, Franz
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- Oxidized multiwalled nanotubes as efficient carbocatalyst for the general synthesis of azines
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The carbocatalytic synthesis of azines (N-N linked diimines) by mild-oxidized multiwalled carbon nanotubes catalyst (oxMWNT) is presented. The material, just with a 5 %wt. loading, is able to carry out a smooth room-temperature metal-free condensation of
- Agnoli, Stefano,Alemán, José,Blanco, Matías,Fraile, Alberto,Valle-Amores, Miguel A.
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p. 174 - 183
(2022/02/02)
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- Reduction over Condensation of Carbonyl Compounds through a Transient Hemiaminal Intermediate Using Hydrazine
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Reduction of carbonyl moieties to the corresponding alcohol using simply hydrazine hydrate has been considerably unfeasible until now due to the well-known condensation reaction. However, herein, we report that using an excess of 20-fold equivalents, the reduction proceeds in excellent yields. 1H NMR study of the reaction and density functional theory (DFT) calculations indicate that the final fate of the hemiaminal intermediate is crucial to obtain the alcohol or the hydrazone.
- Vilches-Herrera, Marcelo,Gallardo-Fuentes, Sebastián,Aravena-Opitz, Mauricio,Yá?ez-Sánchez, Mauricio,Jiao, Haijun,Holz, Jens,B?rner, Armin,Lühr, Susan
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p. 9213 - 9218
(2020/08/14)
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- Dihydrazone compound high in affinity with Abeta protein and Tau protein, derivative thereof, and applications of dihydrazone compound and derivative
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The invention provides a dihydrazone compound high in affinity with Abeta protein and Tau protein, a derivative thereof, and applications of the dihydrazone compound and the derivative. The structureof the dihydrazone compound is represented by formula I. The dihydrazone compound can be directly taken as a fluorescence probe used for detecting neurofibrillary tangles in vivo or in tissue samples;when the dihydrazone compound is adopted in nuclear medicine imaging, appropriate radioisotopes are needed for labeling. The dihydrazone compound is especially suitable to be used for diagnosis of neurodegenerative diseases, and diagnosis of patients with diseases with Abeta plaques including Alzheimer's disease.
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Paragraph 0029-0031; 0038-0040
(2019/05/15)
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- Glucose:urea:NH4Cl low melting mixture for the synthesis of symmetric azines
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Alternate reaction media have become very important due to the problems created by the highly volatile nature of the solvents. The deep eutectic mixture is a kind of an alternate reaction medium which has emerged in recent years. Low melting mixtures were introduced by making the deep eutectic mixture more cost-effective and renewable by introducing carbohydrates into it. The properties of low melting mixtures include easiness to prepare, usage of low-cost components, biodegradability, solubility in water, easy separation from organic compounds, etc. The low melting mixtures such as glucose:urea:NH4Cl, glucose:ChCl, glucose:urea:ChCl, glycerol:urea:NH4Cl, and ethylene glycol:urea:NH4Cl were used in different ratios for the reactions. The properties such as viscosity, density, acidity, glass transition temperature, and thermal stability were studied. An unusual method for the synthesis of symmetrical azines is introduced wherein benzaldehyde and hydroxylamine are reacted in the presence of glucose:urea:NH4Cl. The method of synthesis needs only less reaction time, temperature and the product was easily separated. The products were confirmed using GC-MS and NMR techniques. The recyclability of glucose:urea:NH4Cl was studied.
- Theresa, Letcy V.,Shaibuna,Sreekumar
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p. 3148 - 3160
(2019/09/03)
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- Unusual synthesis of azines and their oxidative degradation to carboxylic acid using iodobenzene diacetate
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Reaction of 3-hydrazonobutan-2-one oxime with aromatic aldehydes resulted in the formation of 1,2-bis(arylidene)hydrazine commonly referred as azine as an unexpected product, instead of expected product 3-(aryl)methylenehydrazonobutan-2-one oxime, which were subsequently oxidized to corresponding aromatic acids with an ecofriendly oxidizing agent iodobenzene diacetate. Azines and carboxylic acids were characterized by IR and NMR (1H, 13C, HMBC, and HMQC) studies.
- Sumran, Garima,Aggarwal, Ranjana,Hooda, Mona,Sanz, Dionisia,Claramunt, Rosa M.
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supporting information
p. 439 - 446
(2018/02/06)
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- Mononuclear half-sandwich iridium and rhodium complexes through C?H activation: Synthesis, characterization and catalytic activity
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A series of mononuclear half-sandwich cyclometalated group 9 (Ir and Rh) metal complexes were synthesized in good yields through metal-mediated C?H bond activation. These air-stable C, N-chelate mode complexes have similar solid state structures. Both experimental results and DFT calculations confirmed that no binuclear complexes were generated in this reaction. The iridium complex 3a exhibited good catalytic activity for the reduction of both electron-rich and electron-poor aryl imines with low catalyst loading in the presence of formic acid/triethylamine (F/T) azeotropic mixture. All complexes were fully characterized by elemental analysis and IR and NMR spectroscopies. The structures of 1a, 1b, 2a, 3a and 4b (see chemical structure formula in Scheme 1 and Scheme 2) were further confirmed by single-crystal X-ray analysis.
- Yao, Zi-Jian,Li, Kuan,Li, Peng,Deng, Wei
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p. 208 - 216
(2017/07/05)
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- Microwave-assisted synthesis of 1-hydrazinophosphonates via the reaction of aldazines with dialkyl phosphite
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A simple, efficient, and novel method has been developed for the synthesis of 1-hydrazinophosphonic acids from aldazines. As described below, treatment of aldazines with diethyl phosphite gives the corresponding 1-hydrazinophosphonic acids in good yields. The reaction proceeds under microwave irradiation at 110°C and neutral condition without any additives such as base, acid, or catalyst. This method is easy, rapid, and gives good yields for the 1-hydrazinophosphonic acids.
- Kaboudin, Babak,Alipour, Soheil
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experimental part
p. 304 - 308
(2012/07/27)
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- Synthesis of azines in solid state: Reactivity of solid hydrazine with aldehydes and ketones
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Highly conjugated azines were prepared by solid state grinding of solid hydrazine and carbonyl compounds such as aldehydes and ketones, using a mortar and a pestle. Complete conversion to the azine product is generally achieved at room temperature within 24 h, without using solvents or additives. The solid-state reactions afford azines as the sole products with greater than 97% yield, producing only water and carbon dioxide as waste.
- Lee, Byeongno,Hyung Lee, Kyu,Cho, Jaeheung,Nam, Wonwoo,Hur, Nam Hwi
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supporting information; experimental part
p. 6386 - 6389
(2012/02/01)
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- Synthesis of functionalized diaryl alkancs from azines
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Substituted diaryl alkanes arc synthesized from bcnzalazines and acctophenone/propiophenone azines via Friedel Craft's reaction with substituted mono- and poly-nuclear aromatic hydrocarbons. Diaryl methanes/ethanes and propanes are obtained by reaction with benzalazine, N,N'-bis (I-phenyl) azine and N, N'-bis (I-propyl) azine, respectively.
- Manih, Rudolf M.,Myrboh, Bekington
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experimental part
p. 146 - 151
(2009/12/01)
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- Reaction of CBrF2-CBrF2 with hydrazones of aromatic aldehydes. Novel efficient synthesis of fluorocontaining alkanes, alkenes and alkynes
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An olefination of hydrazones of aromatic aldehydes by CBrF2-CBrF2 under copper catalysis was investigated. In situ prepared aldehydes hydrazones were converted to (3-bromo-2,2,3,3-tetrafluoropropyl)arenes by reaction with CBrF2-CBrF2 in the presence of CuCl. Subsequent elimination of HF by sodium hydroxide resulted in stereospecific formation of fluorocontaining alkenes. Elimination proceeds stereoselectively, only Z -isomers of alkenes are formed. Elimination of two molecules of HF from (3-bromo-2,2,3,3-tetrafluoropropyl)arenes by treatment with potassium tert -butoxide leads to formation of (bromodifluoromethyl)alkynes. As a result a simple and efficient transformation of aromatic aldehydes to range of various fluorinated alkanes, alkenes and alkynes was elaborated.
- Nenajdenko, Valentine G.,Varseev, Georgy N.,Korotchenko, Vasily N.,Shastin, Alexey V.,Balenkova, Elisabeth S.
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p. 1339 - 1345
(2007/10/03)
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- A novel approach to 2-chloro-2-fluorostyrenes
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A new general catalytic olefination reaction (COR) of aromatic and heteroaromatic aldehydes and ketones was applied to synthesise 2-chloro-2-fluorostyrenes. The two-stage procedure includes the transformation of carbonyl compounds into hydrazones followed by treatment with CFCl3 mediated by copper catalysis. Trichlorofluoromethane was used as a chlorofluoromethylene transfer reagent. The reaction proceeds stereoselectively and the target alkenes were obtained in high yield. A proposed mechanism for the reaction is discussed. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Nenajdenko, Valentine G.,Shastin, Alexey V.,Korotchenko, Vasily N.,Varseev, Georgy N.,Balenkova, Elisabeth S.
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p. 302 - 308
(2007/10/03)
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- A novel direct synthesis of (2,2-difluorovinyl)benzenes from aromatic aldehydes
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A novel catalytic approach to (2,2-difluorovinyl)benzenes has been developed. It was found that hydrazones of aromatic aldehydes generated in situ could be converted to the corresponding (2,2-difluorovinyl)benzenes by catalytic olefination reaction (COR) with dibromodifluoromethane in the presence of CuCl.
- Nenajdenko, Valentine G.,Varseev, Georgy N.,Korotchenko, Vasily N.,Shastin, Alexey V.,Balenkova, Elisabeth S.
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p. 115 - 118
(2007/10/03)
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- A novel approach to fluoro-containing alkenes
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A new and general one-pot transformation of aromatic aldehydes to fluorinated olefins containing -CH=C(Cl)CF3 or -CH=C(F)CClF2 moieties is described. Freons CCl3CF3 and CCl2FCClF2 were used as trifluoromethyl and difluoromethyl C2-building blocks respectively. A proposed mechanism for the reaction is discussed.
- Korotchenko, Vasily N,Shastin, Alexey V,Nenajdenko, Valentine G,Balenkova, Elisabeth S
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p. 7519 - 7527
(2007/10/03)
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- A novel synthesis of β,β-dibromostyrenes
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A new simple and efficient transformation of aromatic aldehydes to β,β-dibromostyrenes and arylbromoacetylenes is described. The olefination procedure was conducted under mild conditions and in good yields.
- Shastin,Korotchenko,Nenajdenko,Balenkova
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p. 2081 - 2084
(2007/10/03)
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- One-pot oxidation of azomethine compounds into arenecarboxylic acids
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Aromatic azomethine compounds, such as aldazines 1, aldoximes 7 and tosylhydrazones 8 oxidized with 30% hydrogen peroxide in the presence of poly(bis-1,2-phenylene) diselenide (6) as catalyst produce arenecarboxylic acids 2 mostly in high to excellent yields. The presented one-pot procedure has a synthetic value.
- Giurg,Said,Syper,Mlochowski
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p. 3151 - 3159
(2007/10/03)
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- A novel synthetic approach to dichlorostyrenes
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We found that N-unsubstituted hydrazones of aromatic aldehydes can be easily converted to the corresponding 1,1-dichlorostyrenes in the reaction with carbon tetrachloride using copper (I) chloride as catalyst. Factors affecting the route of the reaction and yields of the products were investigated. A proposed mechanism for the reaction is discussed. (C) 2000 Published by Elsevier Science Ltd.
- Shastin,Korotchenko,Nenajdenko,Balenkova
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p. 6557 - 6563
(2007/10/03)
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- Thiocarbamoylation of amine-containing compounds 6. Reactions of tetramethylthiuram disulfide with hydrazones of aromatic aldehydes
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Thiocarbamoylation of hydrazones of aromatic aldehydes with tetramethylthiuram disulfide (TMTD) afforded diarylaldazines, 4,4-dimethylthiosemicarbazide, and 5-dimethylamino-l,3,4-thiadiazole-2-thiol. In addition, the reaction of TMTD with salicylaldehyde
- Boi, Luu Van,Floria, V.
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p. 344 - 347
(2007/10/03)
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- Some aryl semicarbazones possessing anticonvulsant activities
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A number of aryl semicarbazones displayed anticonvulsant activity in the maximal electroshock (MES) and subcutaneous pentylenetetrazone (scPTZ) screens when administered intraperitoneally to mice.When given by the oral route to rats, protections was affor
- Dimmock, J. R.,Sidhu, K. K.,Tumber, S. D.,Basran, S. K.,Chen, M.,et al.
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p. 287 - 302
(2007/10/02)
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- Oxidative Transformations of Aldazines and Ketazines with Organic Peroxyacids
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Oxidation of aromatic aldazines and ketazines with various peroxycarboxylic acids was investigated.It was found that one part of azine molecule 2 was converted into carbonyl compound 1 or related acid 3 while the second part was transformed into carboxylic ester 4 related to peroxyacid used as an oxidant.It was revealed that aromatic azines could be used as a source of diazaarylmethanes and mechanisms of reactions studied were postulated. aldazines, carboxylic esters, ketazines, oxidation, peroxycarboxylic acids
- Mlochowski, J.,Giurg, M.
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p. 2333 - 2342
(2007/10/02)
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- CONDENSATION OF p-(DIMETHYLAMINO)BENZALDEHYDE WITH HYDRAZINE IN A MICELLAR MEDIUM
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The rate of the condensation of p-(dimethylamino)benzaldehyde with hydrazine in aqueous solution and the yield of the product (the amine) rise by two orders of magnitude in presence of micelles of sodium dodecyl sulfate.It was found that the micellar effect in the kinetics is manifested at the first dimolecular stage of the reaction of the aldehyde with hydrazine and is explained by the concentrating of the reactants in the micelles.The rate constants of the condensation of hydrazine with a number of substituted benzaldehydes conform to the Hammett equation with a low positive value of ρ.
- Yatsimirskii, A. K.,Yatsimirskaya, N. T.,Krivova, S. B.
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p. 752 - 757
(2007/10/02)
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