2299-73-2Relevant academic research and scientific papers
Ruthenium(ii)-catalysed 1,2-selective hydroboration of aldazines
Gunanathan, Chidambaram,Pradhan, Subham,Thiyagarajan, Subramanian
supporting information, p. 7147 - 7151 (2021/08/30)
Herein, an efficient and simple catalytic method for the selective and partial reduction of aldazines using ruthenium catalyst [Ru(p-cymene)Cl2]2 (1) has been accomplished. Under mild conditions, aldazines undergo the addition of pinacolborane in the presence of a ruthenium catalyst, which delivered N-boryl-N-benzyl hydrazone products. Notably, the reaction is highly selective, and results in exclusive mono-hydroboration and desymmetrization of symmetrical aldazines. Mechanistic studies indicate the involvement of in situ formed intermediate [{(η6-p-cymene)RuCl}2(μ-H-μ-Cl)] (1a) in this selective hydroboration.
Synthesis and antimicrobial activity of some new coumarin and dicoumarol derivatives
El-Metwally, Souad A.,Regal, Mohsen K. A.,Shaban, Safa S.
, (2020/01/22)
PTC reaction of coumarin derivative 1 with alkyl halides afforded C4 oxygen alkylation products 2a-d in appreciative yield, whereas with phenyl isothiocyanate gives the C3 addition product 4; also, one-pot three-component PTC reactio
Synthesis and Antimicrobial Activity of Some New Coumarin and Dicoumarol Derivatives
El-Metwally, S. A.,Regal, M. K. A.,Shaban, S. S.
, p. 438 - 447 (2020/06/30)
Abstract: Phase transfer catalysis reaction of 4-hydroxy-6-methyl-2H-chromen-2-one with alkyl halides afforded C4 oxygen alkylation products of 2H-chromen-2-one derivatives in appreciative yield, whereas with phenyl isothiocyanate gives the C3 addition product of 4-hydroxy-6-methyl-2-oxo-N-phenyl-2H-chromene-3-carbothioamide, also one pot three component phase transfer reaction was investigated. Treatment of 4-hydroxy-6-methyl-2H-chromen-2-one with aromatic aldehydes in different molar ratios gives 3?arylidine and the dicoumarol derivatives. However pyrano chromene and pyrano pyridine were obtained by reaction of arylidine with ethyl acetoacetate through Michael cycloaddition reaction. The stability of pyrone ring in 3-arylidine and dicoumarol towards different nucleophilic reagents under reflux and/or fusion conditions has been studied by the action of, hydrazine hydrate, ammonium acetate, methyl amine and p-toluidine afforded compounds 1,2-bis(benzo[d][1,3]dioxol-5-ylmethylene)hydrazine, 1,2-bis(4-methoxybenzylidene)hydrazine and 2,6-bis((2,6-dihydroxy-3-methylphenyl)(hydroxy)methylene)-1-(4-methoxyphenyl)-4-(p-tolyl) piperidine-3,5-dione derivatives. The antimicrobial activity of some synthesized compounds has been investigated.
Glucose:urea:NH4Cl low melting mixture for the synthesis of symmetric azines
Theresa, Letcy V.,Shaibuna,Sreekumar
, p. 3148 - 3160 (2019/09/03)
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.
Dihydrazone compound high in affinity with Abeta protein and Tau protein, derivative thereof, and applications of dihydrazone compound and derivative
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Paragraph 0029-0031; 0047-0049, (2019/05/15)
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.
Unprecedented synthesis of symmetrical azines from alcohols and hydrazine hydrate using nickel based NNN-pincer catalyst: An experimental and computational study
Shiekh, Bilal Ahmad,Kaur, Damanjit,Godara, Sachin Kumar
, p. 19 - 23 (2019/03/02)
Azines are having widespread applications in both industry as well as synthetic chemistry. Thus new catalytic synthetic protocols are desirable as they are greener alternatives than traditional methods of synthesis. Thus, herein a novel earth abundant nickel based NNN-pincer catalyst Ni(BPEA)(Cl2) is synthesized for the first time for the direct transformation of alcohols and hydrazine hydrate into symmetrical azines. This catalytic reaction is accompanied by dehydrogenative coupling of alcohols and hydrazine hydrate and is carried out in presence of a base. Theoretical calculations supported by experimental evidence have been performed for understanding the mechanistic insights of the reaction.
Unusual synthesis of azines and their oxidative degradation to carboxylic acid using iodobenzene diacetate
Sumran, Garima,Aggarwal, Ranjana,Hooda, Mona,Sanz, Dionisia,Claramunt, Rosa M.
supporting information, p. 439 - 446 (2018/02/06)
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.
Li+-Induced fluorescent metallogel: A case of ESIPT-CHEF and ICT phenomenon
Dixit, Manish Kumar,Dubey, Mrigendra
, p. 23762 - 23772 (2018/09/29)
A fluorescent metallogel (1percent w/v) has been synthesized from non-fluorescent ingredients viz. the smallest possible low molecular weight aromatic symmetrical ligand H2SA (1) and LiOH in a chloroform and methanol mixture. The chelation of Li+ is not only responsible for the inhibition of excited state intramolecular proton transfer (ESIPT) or the origin of fluorescence through chelation enhanced fluorescence (CHEF) in 1, but also for aggregation leading to gelation. The metallogel obtained from 1/Li+ reveals a fibrous morphology while 1 with other, bigger size, alkali metal ions like Na+/K+/Cs+ demonstrates the growth of crystals with different shapes. The effect of the size of the alkali metal ion over gel formation is well explored by FTIR, UV-vis, fluorescence, average lifetime measurements, SEM and PXRD. The metallogel shows multi-stimuli responsive behaviour towards thermal and mechanical stress as well as reswelling properties. The regioisomer H2PBA (2) also shows emission upon treatment with LiOH due to the presence of intramolecular charge transfer (ICT), this is well established by various experiments. The mechanism of gel formation is well established by FTIR, 1H NMR, UV-vis, fluorescence, lifetime measurements, SEM and single crystal and powder XRD instrumental techniques. The involvement of various phenomena in gel formation has been further supported by other synthesized model compounds viz. H2MBA (3), PMO (4), H2SEA (5) and H2SPA (6). True gel phase material is proved by detailed rheological experiments.
Synthesis and Properties of New 4-Oxo-4,5-dihydro-1,3-oxazolium Perchlorates
Lukina, D. Yu.,Strelkov,Dyadyuchenko,Chigorina,Dotsenko,Kosulina
, p. 2504 - 2512 (2019/04/03)
D-Pantoic acid amide obtained by treatment of D-(–)-pantolactone with ammonia reacted with acetic anhydride in the presence of perchloric acid to give 5-[2-(acetoxy)-1,1-dimethylethyl]-2-methyl-4-oxo- 4,5-dihydro-1,3-oxazolium perchlorate. Reaction of the
Mononuclear half-sandwich iridium and rhodium complexes through C?H activation: Synthesis, characterization and catalytic activity
Yao, Zi-Jian,Li, Kuan,Li, Peng,Deng, Wei
, p. 208 - 216 (2017/07/05)
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.
