- A Convenient 1,3-Dipolar Cycloaddition Reaction for the Synthesis of Spirooxindoles and Some Other Spirocompounds Containing the 1,3,4-Oxadiazole Moiety
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A series of spiro[indoline-3,2′-[1,3,4]oxadiazol]-2-ones were prepared from the reaction of isatin derivatives and hydrazonoyl chlorides through the 1,3-dipolar cycloaddition reaction. This method has some important aspects, such as mild reaction condition, easy purification, and high yield of products. Also, the synthesis of spiro[acenaphthylene-1,2′-[1,3,4]oxadiazol]-2-one and spiro[[1,3,4]oxadiazole-2,9′-phenanthren]-10′-one were studied under the same condition. The structures were confirmed spectroscopically (IR,1H- and13C-NMR, and EI-MS) and by elemental analyses. A plausible mechanism for this reaction is proposed.
- Alizadeh, Abdolali,Moafi, Leila
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- A CO2-Catalyzed Transamidation Reaction
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Transamidation reactions are often mediated by reactive substrates in the presence of overstoichiometric activating reagents and/or transition metal catalysts. Here we report the use of CO2as a traceless catalyst: in the presence of catalytic amounts of CO2, transamidation reactions were accelerated with primary, secondary, and tertiary amide donors. Various amine nucleophiles including amino acid derivatives were tolerated, showcasing the utility of transamidation in peptide modification and polymer degradation (e.g., Nylon-6,6). In particular,N,O-dimethylhydroxyl amides (Weinreb amides) displayed a distinct reactivity in the CO2-catalyzed transamidation versus a N2atmosphere. Comparative Hammett studies and kinetic analysis were conducted to elucidate the catalytic activation mechanism of molecular CO2, which was supported by DFT calculations. We attributed the positive effect of CO2in the transamidation reaction to the stabilization of tetrahedral intermediates by covalent binding to the electrophilic CO2
- Yang, Yang,Liu, Jian,Kamounah, Fadhil S.,Ciancaleoni, Gianluca,Lee, Ji-Woong
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p. 16867 - 16881
(2021/11/18)
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- Regioselective Decarboxylative Cycloaddition Route to Fully Substituted 3-CF3-Pyrazoles from Nitrilimines and Isoxazolidinediones
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1,4-Diaryl-5-carboxamido substituted 3-trifluoromethylpyrazoles are obtained with exclusive regioselectivity under transition-metal-free conditions. This decarboxylative [3+2] cycloaddition protocol was enabled by employing trifluoromethyl nitrilimines as 1,3-dipoles, and isoxazolidinediones as CO2-masked alkynyl dipolarophiles. The applicability of this method is further manifested by its compatibility with difluoromethyl, alkyl, aryl, and heteroaryl nitrilimines, as well as the preparation of 4-carboxylic amido analogue of drug Celebrex. (Figure presented.).
- Tian, Yu-Chen,Li, Jun-Kuan,Zhang, Fa-Guang,Ma, Jun-An
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supporting information
p. 2093 - 2097
(2021/03/15)
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- HYDRAZIDE DERIVATIVES AND THEIR SPECIFIC USE AS ANTIBACTERIAL AGENTS BY CONTROLLING ACINETOBACTER BAUMANNII BACTERIUM
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The present invention relates to compounds of the following general formula (I): or a pharmaceutically acceptable salt and/or solvate thereof, their use as a drug, in particular as antibacterial agent, notablyforpreventingand/or treating disorders associa
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Page/Page column 45-46
(2020/09/08)
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- Copper-Catalyzed Tandem Dehydrocyanation and [3+2] Cyclo-addition Reactions of Phenacylmalononitriles: Regioselective Synthesis of Functionalized 4-Benzoyl-5-cyanopyrazoles under Mild Conditions
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A novel copper-catalyzed [3+2] cycloaddition reaction with concomitant in situ generation of benzoylacrylonitriles and nitrile imines from phenacylmalononitriles and hydrazonoyl chlorides, respectively, is reported. The reaction was performed using copper(I) chloride as catalyst and N-methylimidazole as a clean complexing agent/weak base to afford the functionalized 4-benzoyl-5-cyanopyrazoles in moderate to good yields and excellent regioselectivity under ambient conditions. This method provides rapid access to a wide range of highly functionalized 4-benzoyl-5-cyanopyrazoles.
- Khaledian, Omid,Yavari, Issa
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p. 1379 - 1386
(2020/04/27)
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- A formal [3+2] cycloaddition reaction of: N -methylimidazole as a masked hydrogen cyanide: Access to 1,3-disubstitued-1 H -1,2,4-triazoles
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N-Methylimidazole (NMI) can act as a masked HCN in the synthesis of 1,3-disubstitued-1H-1,2,4-triazoles via a formal cycloaddition reaction of hydrazonoyl chloride with NMI. The product was proved to be formed via an initial nucleophilic substitution of hydrazonoyl chloride with NMI following cyclization and two sequential C-N bond cleavages. This journal is
- Yavari, Issa,Khaledian, Omid
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supporting information
p. 9150 - 9153
(2020/10/02)
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- Intramolecular Diels-Alder and [3+2] Cycloaddition Reactions in the One-Pot Synthesis of Epoxypyrrolo[3,4-g]indazoles
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A one-pot approach for the synthesis of epoxypyrrolo[3,4- g ]indazoles is presented. The first step was initiated by a three-component reaction of an isocyanide, a dialkyl acetylenedicarboxylate, and 2-furancarboxylic acid, and led to 1,3-dioxoepoxyisoindole, followed by the addition of hydrazonoyl chloride through a [3+2]-cycloaddition reaction in the second step. The key step in the formation of final compound involves a bicyclization strategy through intramolecular Diels-Alder (IMDA) reaction.
- Alizadeh, Abdolali,Amir Ashjaee Asalemi, Kaveh,Halvagar, Mohammadreza
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supporting information
p. 2936 - 2944
(2019/07/22)
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- [3+2]-cycloaddition of in situ generated nitrile imines and acetylene for assembling of 1,3-disubstituted pyrazoles with quantitative deuterium labeling
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A novel synthetic methodology for the preparation of 1,3-disubstituted pyrazoles from in situ generated nitrile imines and acetylene is reported. The reactions are performed in a simple two-chamber reactor. One part of the reactor is loaded with hydrazonoyl chloride precursors of active nitrile imine species and a base. The other part is used to generate acetylene from CaC2 and water. Partitioning of the reactants improves the yields of desired pyrazoles up to 99% and simplifies their isolation to a simple procedure of solvent evaporation. The approach requires no complex equipment and utilizes inexpensive, safe, and easy to handle calcium carbide as a starting material. A model deuterium incorporation is carried out according to the developed methodology, producing a series of novel 4,5-dideuteropyrazoles with excellent deuterium enrichment. Theoretical calculations on reaction mechanism and characterization of possible intermediate structures were performed.
- Voronin, Vladimir V.,Ledovskaya, Maria S.,Gordeev, Evgeniy G.,Rodygin, Konstantin S.,Ananikov, Valentine P.
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p. 3819 - 3828
(2018/04/14)
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- Synthesis of Spirobidihydropyrazole through Double 1,3-Dipolar Cycloaddition of Nitrilimines with Allenoates
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The double 1,3-dipolar cycloaddition of allenoates with nitrilimines has been achieved under mild reaction conditions, affording a variety of spirobidihydropyrazoles in moderate to excellent yields with excellent diastereoselectivities. The reaction diastereoselectively constructs double dihydropyrazole moieties and two chiral centers including a spiro carbon center.
- Liu, Honglei,Jia, Hao,Wang, Bo,Xiao, Yumei,Guo, Hongchao
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supporting information
p. 4714 - 4717
(2017/09/23)
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- KOt-Bu promoted homocoupling and decomposition of N'-aryl acylhydrazines: synthesis of unsymmetric N',N'-diaryl acylhydrazines
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The KOt-Bu promoted homocoupling and decomposition of N'-aryl acylhydrazines has been achieved. The method allows for a novel and efficient synthesis of unsymmetric N',N'-diaryl acylhydrazines under mild reaction conditions. The reaction probably proceeds via the generation of N'-centered acylhydrazine radicals and the subsequent homolytic aromatic substitution.
- Wang, Wei-Juan,Zhang, Ting,Duan, Li-Jun,Zhang, Xue-Jing,Yan, Ming
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p. 9073 - 9080
(2015/11/09)
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- Synthesis of 4′-[3-methyl-5-thioxo-1H-1,2,4-triazol-4(5H)-yl]- 2′,5′-diphenyl-2′,4′-dihydro spiro[indolin-3,3′[1, 2,4]triazol]-2-one derivatives
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In this paper 1,3-dipolar cycloaddition reaction has been studied. An efficient synthesis of 4′-[3-methyl-5-thioxo-1H-1,2,4-triazol-4(5H)-yl]- 2′,5′-diphenyl-2′,4′-dihydro spiro(indolin-3,3′[1, 2,4]triazol)-2-one derivatives using triethylamine in MeCN at room temperature is reported. The structures of the obtained compounds were confirmed by means of elemental analysis, MS and spectral (IR, 1H, and 13C NMR) methods.
- Bazian, Atiye,Taheri, Milad,Alavi, Haniyeh
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p. 586 - 592
(2014/05/20)
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- Synthesis and antifungal activities of New pyrazole derivatives via 1,3-dipolar cycloaddition reaction
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A series of cycloadducts - pyrazoles via 1,3-dipolar cycloaddition reactions of generated nitrilimines with N-(4-chloro-2-fluorophenyl)maleimide were described. The novel compounds synthesized were characterized by 1H NMR, MS, and elemental analysis. The fungicidal tests showed that most of the title compounds exhibit significant fungicidal activities against Corynespora cassiicola.
- Zhang, Chuan-Yu,Liu, Xing-Hai,Wang, Bao-Lei,Wang, Su-Hua,Li, Zheng-Ming
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scheme or table
p. 489 - 493
(2011/02/21)
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- A facile synthesis of acylhydrazines from acylbenzotriazoles
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Acylbenzotriazoles were found to react with substituted hydrazines and aqueous hydrazine under very mild conditions, thus affording a facile synthesis of three types of acylhydrazines in moderate to excellent yields.
- Wang, Xiaoxia,Yu, Hongping,Xu, Peifang,Zheng, Renwei
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p. 595 - 597
(2007/10/03)
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- 1,3-Diarylcycloalkanopyrazoles and diphenyl hydrazides as selective inhibitors of cyclooxygenase-2
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Novel 1,3-diarylcycloalkanopyrazoles 1, and diphenyl hydrazides 2 were identified as selective inhibitors of cyclooxygenase-2. The 1,3-diaryl substitution pattern of the pyrazole ring in 1 differentiates these compounds from most of the known selective COX-2 inhibitors that contain two aryl rings at the adjacent positions on a heterocyclic or a phenyl ring. Similarly, the two phenyl rings in 2 are also separated by three atoms. SAR of both phenyl rings in 1 and 2, and the aliphatic ring in 1 will be discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.
- Sui, Zhihua,Guan, Jihua,Ferro, Michael P.,McCoy, Kathy,Wachter, Michael P.,Murray, William V.,Singer, Monica,Steber, Michele,Ritchie, Dave M.,Argentieri, Dennis C.
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p. 601 - 604
(2007/10/03)
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- THE USE OF 2,2,2-TRICHLORO-1-ARYLETHANONES AS BENZOYLATING AGENTS
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The preparation of several amides and hydrazides from the reaction of the title compounds with different nitrogen nucleophiles is shown to be a general high-yield conversion of synthetic utility.
- Rebelo, Ricardo Andrade,Rezende, Marcos Caroli,Nome, Faruk,Zucco, Cesar
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p. 1741 - 1748
(2007/10/02)
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