41097-38-5Relevant academic research and scientific papers
Oxidized multiwalled nanotubes as efficient carbocatalyst for the general synthesis of azines
Agnoli, Stefano,Alemán, José,Blanco, Matías,Fraile, Alberto,Valle-Amores, Miguel A.
, p. 174 - 183 (2022/02/02)
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
Traceless Isoprenylation of Aldehydes via N-Boc-N-(1,1-dimethylallyl)hydrazones
Heerdegen, Desirée,Junker, Julia,Dittrich, Sebastian,Mayer, Peter,Bracher, Franz
, p. 3680 - 3687 (2020/06/02)
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.
Reduction over Condensation of Carbonyl Compounds through a Transient Hemiaminal Intermediate Using Hydrazine
Vilches-Herrera, Marcelo,Gallardo-Fuentes, Sebastián,Aravena-Opitz, Mauricio,Yá?ez-Sánchez, Mauricio,Jiao, Haijun,Holz, Jens,B?rner, Armin,Lühr, Susan
, p. 9213 - 9218 (2020/08/14)
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.
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; 0038-0040, (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.
Electrochemical Hydrogenation with Gaseous Ammonia
Li, Jin,He, Lingfeng,Liu, Xu,Cheng, Xu,Li, Guigen
supporting information, p. 1759 - 1763 (2019/01/16)
As a carbon-free and sustainable fuel, ammonia serves as high-energy-density hydrogen-storage material. It is important to develop new reactions able to utilize ammonia as a hydrogen source directly. Herein, we report an electrochemical hydrogenation of alkenes, alkynes, and ketones using ammonia as the hydrogen source and carbon electrodes. A variety of heterocycles and functional groups, including for example sulfide, benzyl, benzyl carbamate, and allyl carbamate were well tolerated. Fast stepwise electron transfer and proton transfer processes were proposed to account for the transformation.
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.
Ligand Redox-Controlled Tandem Synthesis of Azines from Aromatic Alcohols and Hydrazine in Air: One-Pot Synthesis of Phthalazine
Chakraborty, Mou,Sengupta, Debabrata,Saha, Tanushri,Goswami, Sreebrata
supporting information, p. 7771 - 7778 (2018/06/11)
A controlled tandem synthetic route to azines from various alcohols and hydrazine hydrate by the use of a Ni(II) complex of 2,6-bis(phenylazo)pyridine as a catalyst is reported. In marked contrast to the previous report, the reaction is operative using an earth-abundant metal catalyst, milder reaction conditions, and aerobic conditions, which though are desirable but unprecedented in the literature. The catalytic reaction has a vast substrate scope including a single-step synthesis of phthalazine from 1,2-benzenedimethanol and hydrazine hydrate via intramolecular coupling. Mechanistic investigation suggests that the coordinated ligand redox controls the reaction by the use of a reversible azo (N=N)/ hydrazo (NH - NH) redox couple where the metal center is used primarily as a template.
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.
Selective Reduction of Azines to Benzyl Hydrazones with Sodium Borohydride Catalyzed by Mesoporous Silica-Supported Silver Nanoparticles: A Catalytic Route towards Pyrazole Synthesis
Charistoudi, Evangelia,Kallitsakis, Michael G.,Charisteidis, Ioannis,Triantafyllidis, Kostas S.,Lykakis, Ioannis N.
supporting information, p. 2949 - 2960 (2017/09/08)
The catalytic activity of supported silver nanoparticles on mesoporous silica was studied, for the selective reduction of azines into benzyl hydrazones using sodium borohydride as mild reducing agent. Different sizes of silver nanoparticles supported on mesoporous silica (Ag/HMS) were successfully prepared by two methods, i.e., wet impregnation followed by reduction with hydrogen at 350 °C and in situ deposition/reduction with a mixture of amines (ethanolamine and ethylenediamine). The Ag/HMS (amines) catalyst was found to promote the selective 1,2-reduction of aryl-substituted azines, compared to the corresponding 1,4-reduction that occurs in general reduction processes. This catalytic transfer hydrogenation process found to be clean, fast and quantitative (>99% yields and selectivity) towards benzyl hydrazone synthesis under mild conditions. Of great importance is that under the present catalytic conditions reducible functional groups remain intact. Formal kinetics, support the in situ formation of silver hydride species being responsible for the reduction process. The presence of protic polar methanol enhanced the catalytic activity of Ag/HMS. Based on the recycling studies the catalytic system Ag/HMS-NaBH4 was found to catalyze the selective reduction of azines nine times without significant loss of its activity. Finally, a one-pot reaction between the in situ produced benzyl hydrazones and a series of nitrostyrenes readily provided the regioselective synthesis of 1,3,5-subtituted pyrazoles, highlighting a useful synthetic application of the catalytic protocol. (Figure presented.).
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.
