21719-59-5Relevant academic research and scientific papers
Divergent construction of pyrazoles via Michael addition of n -arylhydrazones to 1,2-diaza-1,3-dienes
Mantenuto, Serena,Mantellini, Fabio,Favi, Gianfranco,Attanasi, Orazio A.
, p. 2014 - 2017 (2015)
The base (NaH)-promoted Michael addition of N-arylhydrazones (AHs) with 1,2-diaza-1,3-dienes (DDs) produces unprecedented β-azohydrazone adducts. Strategically, the use of AHs as acyl anion equivalents (d1 synthon) and DDs as α-electrophiles (a
From Phenylhydrazone to 1H-1,2,4-Triazoles via Nitrification, Reduction and Cyclization
Hao, Liqiang,Wang, Guodong,Sun, Jian,Xu, Jun,Li, Hongshuang,Duan, Guiyun,Xia, Chengcai,Zhang, Pengfei
supporting information, p. 1657 - 1662 (2020/03/19)
Herein we report an annulation of phenylhydrazone via a tandem nitrification, reduction, cyclization protocol employing cobalt nitrate and 1,2-dichloroethane to produce substituted 1H-1,2,4-triazoles. Notably, 1,2-dichloroethane serves both the solvent and a hydrogen source for transfer hydrogenation. This methodology works under mild conditions, providing a direct approach for the synthesis of 1H-1,2,4-triazoles. (Figure presented.).
Stereospecific copper(II)-catalyzed tandem ring opening/oxidative alkylation of donor-acceptor cyclopropanes with hydrazones: Synthesis of tetrahydropyridazines
Mishra, Manmath,De, Pinaki Bhusan,Pradhan, Sourav,Punniyamurthy, Tharmalingam
, p. 10901 - 10910 (2019/09/13)
Aerobic copper(II)-catalyzed tandem ring opening and oxidative C-H alkylation of donor-acceptor cyclopropanes with bisaryl hydrazones is accomplished to produce tetrahydropyridazines, in which copper(II) plays dual role as a Lewis acid as well as redox catalyst. The reaction is stereospecific, and optically active cyclopropanes can be reacted with high optical purities (89-98% enantiomeric excess). The substrate scope, functional group tolerance, dual role of the copper(II) catalyst, and the use of air as an oxidant are the important practical features. A product bearing a 3-bromoaryl group can be subjected to Pd-catalyzed Suzuki coupling with boronic acid in high yield.
Fe+3-montmorillonite K10 as an Efficient Reusable Heterogeneous Catalyst for the Grind Mediated Synthesis of 14-aryl-14H-dibenzo [a,j]xanthenes
Fekri, Leila Z.,Nikpassand, Mohammad,Fard, Hajar S.,Marvi, Omid
, p. 135 - 142 (2016/03/01)
Background: Xanthenes are an important class of organic compounds and have also received significant attention due to their wide range of pharmacological activities such as antibacterial, antiviral, antiinflammatory activities, antagonists for the paralyzing action of zoxazolamine and efficiency in photodynamic therapy, a well-known method for controlling the localized tumors. Natural sources are also rich of xanthene compounds. Popularly known pigments, santalin have been isolated from plant species. Furthermore, these compounds can be emerged as pH-sensitive fluorescent materials for visualization of biomolecules, in laser technologies and as dyes. There are several reports in the literature for the synthesis of xanthenes such as alkylations of heteroatoms, cyclodehydrations, cyclocondensations between 2-hydroxyaromatic aldehydes and 2- tetralone, trapping of benzynes by phenols and intramolecular phenyl-carbonyl coupling reactions of benzaldehydes and acetophenones bearing tethered carbonyl chains in the presence of hexamethylphosphoramide and SmI2. Other methods for the synthesis of xanthenes include the reaction of formamide with β-naphthol, carbon monoxide, and 1- hydroxymethyl-naphthalen-2-ol. Methods: procedure a: A mixture of substituted benzaldehyde, 2-naphtol and Fe+3-montmorillonite K10 was mixed. After completion of the reaction, the product was solved in CHCl3 (3×10 mL) and insoluble catalyst was removed by filtration. The organic phase including the product and chloroform was evaporated under vacuum. The resulting crude material was purified by recrystallization from EtOH to afford pure products. procedure b: A mixture of substituted benzaldehyde, phenylhydrazine and Fe+3-montmorillonite K10 were added to a mortar and the mixture was pulverized with a pestle. After completion of the reaction, 2-naphtol was added to the consulting mixture and pulverized with a pestle. The organic phase including the product and chloroform was evaporated under vacuum. The resulting crude material was purified by recrystallization from EtOH to afford pure products. Results: As part of our going interest for the development of efficient and environmentally friendly procedures for the synthesis of heterocyclic and pharmaceutical compounds, we wish to report the first grind mediated synthesis of some derivatives of xanthenes using catalytic amount of Fe+3-montmotillonite. Conclusion: In conclusion, we have investigated the Fe+3-montmorillonite K10 under grinding as a mild and efficient catalyst for the synthesis of substituted 14-aryl-14H-dibenzo [a,j]xanthenes. The remarkable advantages offered by this method are: catalyst is inexpensive, non-toxic, easy handling and reusability, simple work-up procedure, short reaction time, high yields of product with better purity and green aspect by avoiding toxic catalyst and hazardous solvent.
A Single Electron Transfer (SET) Approach to C-H Amidation of Hydrazones via Visible-Light Photoredox Catalysis
Zhang, Muliang,Duan, Yingqian,Li, Weipeng,Xu, Pan,Cheng, Jian,Yu, Shouyun,Zhu, Chengjian
supporting information, p. 5356 - 5359 (2016/11/02)
The reductive single electron transfer (SET) umpolung amination of aldehyde-derived hydrazones has been developed through visible-light-promoted photoredox catalysis. The ideal transformation of hydrazones into the corresponding hydrazonamide through selective carbon-hydrogen (C-H) bond functionalization represents one of the most step- and atom-economical methods. This SET umpolung strategy features mild conditions and a remarkably broad substrate scope, offering an entirely new substrate class to direct C-H amination.
Ytterbium(III) perfluorooctanoate catalyzed one-pot, three-component synthesis of fully substituted pyrazoles under solvent-free conditions
Shen, Li,Cao, Song,Liu, Nianjin,Wu, Jingjing,Zhu, Longjie,Qian, Xuhong
experimental part, p. 1341 - 1344 (2009/04/06)
A convenient one-pot synthesis of fully substituted pyrazoles via three-component condensations of phenylhydrazine, aldehydes, and 1,3-dicarbonyl compounds using ytterbium perfluorooctanoate [Yb(PFO)3] as catalyst under solvent-free conditions is described. The reusable catalyst can be easily prepared and was efficient for the reaction. A possible mechanism is suggested. Georg Thieme Verlag Stuttgart.
