935-07-9Relevant academic research and scientific papers
Aryl Pyrazoles from Photocatalytic Cycloadditions of Arenediazonium
Cardinale, Luana,Neumeier, Michael,Majek, Michal,Jacobi Von Wangelin, Axel
supporting information, p. 7219 - 7224 (2020/10/02)
A photocatalytic synthesis of 1,5-diaryl pyrazoles from arenediazoniums and arylcyclopropanols is reported. The reaction proceeded under mild conditions (rt, 20 min) with catalytic [Ru(bpy)3]2+ under blue-light irradiation and exhibited compatibility with several functional groups (e.g., I, SF5, SO2NH2, N3, CN) and perfect levels of regiocontrol. Mechanistic studies (luminescence spectroscopy, CV, DFT, radical trapping, quantum yield determination) documented an initial oxidative quenching of the excited photocatalyst and the operation of a radical-chain mechanism.
Polyaromatic hydrocarbon derivatized azo-oximes of cobalt(iii) for the ligand-redox controlled electrocatalytic oxygen reduction reaction
Dinda, Soumitra,Roy, Syamantak,Patra, Sarat Chandra,Bhandary, Subhrajyoti,Pramanik, Kausikisankar,Ganguly, Sanjib
, p. 3737 - 3747 (2020/03/17)
A pair of ligands HLPyr1a and HLAnc1b (Pyr = pyrene, Anc = anthracene) incorporating π-electron-rich polycyclic aromatic hydrocarbons (PAHs), viz. pyrene and anthracene moieties respectively, in conjunction with electron-poor azo-oxime groups was synthesized. The tris complexes [CoIII(LPyr)3] 2a and [CoIII(LAnc)3] 2b were also prepared and structurally authenticated by X-ray diffraction. They exhibit significant redox and optoelectronic properties, which were analyzed by density functional theory (DFT) and time dependent density functional theory (TD-DFT). Theoretical investigation further revealed that the coordinated ligands act as superior electron reservoirs in comparison to the free ligands and transfer electrons through the PAH moieties. This property was smartly exploited to scrutinize the aptitude of the cobalt(iii) complexes for the electrocatalytic oxygen reduction reaction (ORR). The catalytic process proceeds via a 4-electron transfer pathway to form hydroxide ions in alkaline medium. The role of the PAHs in the complexes 2a and 2b in providing a pool of electrons was further emphasized via substituting them with phenyl groups, as in [CoIII(LPh)3] 2c, when the catalytic ORR activity was significantly diminished. Moreover, the activity was completely lost when the PAHs were replaced by methyl groups, as in [CoIII(LMe)3] 2d.
Shaken, not stirred: a schools test for aldehydes and ketones
Plater, M John
, p. 104 - 107 (2019/11/22)
A schools test for aldehydes and ketones in water at room temperature using test tubes has been developed in this laboratory using either phenylhydrazine hydrochloride or phenylhydrazine hydrochloride with NaOAc . 3H2O. The role of one equivalent of a strong or weak acid which catalyses the reaction is discussed.
The use of enaminones and enamines as effective synthons for MSA-catalyzed regioselective synthesis of 1,3,4-tri- And 1,3,4,5-tetrasubstituted pyrazoles
Duan, Liancheng,Zhou, Hui,Gu, Yucheng,Gong, Ping,Qin, Mingze
supporting information, p. 16131 - 16137 (2019/11/03)
In the present work, an efficient regioselective synthesis of 1,3,4-tri- and 1,3,4,5-tetrasubstituted pyrazoles via a methanesulfonic acid (MSA)-catalyzed reaction of hydrazones with enaminones or enamines is reported. Mechanistically, the formation of the title compounds involves the [2+3] cycloaddition of hydrazones with enaminones or enamines followed by aromatization with acid and oxygen. This convenient method under mild conditions with various hydrazones, enaminones, and enamines was well-tolerated to afford products in good to excellent yields. Compared with the literature methods, this strategy has advantages such as materials that are available economically, metal-free catalysis, excellent regioselectivity, and high efficiency.
Oxidized single-walled carbon nanotubes (swcns-cooh) as a new catalyst for the protection of carbonyl groups as hydrazones
Borazjani, Maryam Kiani,Safaei, Hamid Reza,Panahandeh, Majid,Kiani, Ali Reza,Kiani, Masoumeh,Mofarahi, Masoud
, p. 279 - 281 (2013/12/04)
Nano-materials are considered as suitable heterogeneous catalysts for many organic reactions. Herein oxidized carbon nanotube (SWCNTs-COOH) has been reported as a heterogeneous catalyst, for protection of carbonyl groups as hydrazones in EtOH at 80 C. The reactions proceed smoothly with good to excellent yields, and the SWCNTs-COOH used can be recycled.
Indolyl and dihydroindolyl N-glycinamides as potent and in vivo active NPY5 antagonists
Wu, Lingyun,Lu, Kai,Packiarajan, Mathivanan,Jubian, Vrej,Chandrasena, Gamini,Wolinsky, Toni C.,Walker, Mary W.
scheme or table, p. 2167 - 2171 (2012/04/18)
A novel series of indolyl and dihydroindolyl glycinamides were identified as potent NPY5 antagonists with in vivo activity from screen hit 1. The dihydroindolyl glycinamide 10a significantly inhibits NPY5 agonist induced feeding at a dose of 0.1 mg/kg. The indolyl glycinamide 12c also inhibits NPY5 agonist induced feeding at a dose of 1 mg/kg. Both compounds 10a and 12c represent potential tools for further investigation into the biology of the NPY5 receptor.
Facile method for conversion of 2-(Chloroseleno)benzoyl chloride into 2-substituted 3-hydroxybenzo[b]selenophenes
Lisiak, Rafal,Mochowski, Jacek
experimental part, p. 4271 - 4281 (2009/12/31)
The easily accessible 2-(chloroseleno)benzoyl chloride has broad application in the synthesis of benzizoselenazol-3(2H)-ones and benzo[b]selenophen-3(2H)-ones. Treatment of 2-acylbenzo[b]selenophen-3(2H)-ones with nitrogen nucleophiles such as hydrazines
Electrochemical formation of methoxy- and cyano(phenylazo)alkanes from aldehyde and ketone phenylhydrazones
Okimoto, Mitsuhiro,Takahashi, Yukio,Kakuchi, Toyoji
, p. 2057 - 2063 (2007/10/03)
Several aldehyde and ketone phenylhydrazones were electrooxidized in MeOH. Electrooxidation in the presence of KI or tetraethylammonium p-toluenesulfonate as the supporting electrolyte afforded the corresponding methoxy(phenylazo)alkanes, whereas electrooxidation in the presence of KI, NaCN, and HOAc afforded the cyano(phenylazo)alkanes.
Synthesis of indomethacin analogues for evaluation as modulators of MRP activity
Maguire, Anita R.,Plunkett, Stephen J.,Papot, Sébastien,Clynes, Martin,O'Connor, Robert,Touhey, Samantha
, p. 745 - 762 (2007/10/03)
Synthesis of a range of indomethacin analogues, required for investigation in combination toxicity assays, bearing both N-benzyl and N-benzoyl groups, is described. Copyright
ALKALINE ISOMERIZATION OF PHENYLHYDRAZONES TO ALKYLPHENYLDIIMIDES
Kuznetsov, M.A.,Suvorov, A.A.
, p. 1684 - 1691 (2007/10/02)
When solutions pf phenylhydrazones in tri- or tetraethylene glycol are heated in the presence of the corresponding sodium glycolate, they undergo isomerization to alkylphenyldiimidates.There is a marked decrease in the isomerization rate in the transition from the hydrazones of aldehydes to the hydrazones of ketones.With the phenylhydrazones of ketones the reaction takes place almost unambiguously, but in the case of hydrazones of aldehydes it is complicated to an appreciable extent by side processes such as indolization and aminonitrile cleavage.
