59812-04-3Relevant academic research and scientific papers
Cobalt-Catalyzed, Directed Intermolecular C-H Bond Functionalization for Multiheteroatom Heterocycle Synthesis: The Case of Benzotriazine
Wu, Weiping,Fan, Shuaixin,Li, Tielei,Fang, Lili,Chu, Benfa,Zhu, Jin
supporting information, p. 5652 - 5657 (2021/08/01)
Transition-metal-catalyzed, directed intermolecular C-H bond functionalization is synthetically useful but heavily underexplored in multiheteroatom heterocycle synthesis. Herein we report a cobalt catalytic method for the formation of a three-nitrogen-bearing benzotriazine scaffold via the coupling of arylhydrazine and oxadiazolone. This synthetic protocol features a low-cost base metal catalyst, a maximum number of heteroatoms built into a heterocycle, a distinct synthetic logic for benzotriazines, a superior step economy, and a broad substrate scope.
Copper-Catalyzed Selective N-Arylation of Oxadiazolones by Diaryliodonium Salts
Soldatova, Natalia S.,Semenov, Artem V.,Geyl, Kirill K.,Baykov, Sergey V.,Shetnev, Anton A.,Konstantinova, Anna S.,Korsakov, Mikhail M.,Yusubov, Mekhman S.,Postnikov, Pavel S.
supporting information, p. 3566 - 3576 (2021/06/16)
Here, we report the method for copper-catalyzed N-arylation of diverse oxadiazolones by diaryliodonium salts under mild conditions in high yields (up to 92%) using available CuI as a catalyst. The developed method allows utilizing both symmetric and unsymmetric diaryliodonium salts bearing auxiliary groups such as 2,4,6-trimethoxyphenyl (TMP). We found that the steric effects in aryl moieties determined the chemoselectivity of N- and O-arylation of the 1,2,4-oxadiazol-5(4H)-ones. Mesityl-substituted diaryliodonium salts demonstrated the high potential as a selective arylation reagent. The structural study suggests that steric accessibility of N-atom in 1,2,4-oxadiazol-5(4H)-ones impact to arylation with sterically hindered diaryliodonium salts. The synthetic application of proposed method was also demonstrated on selective arylation of 1,3,4-oxadiazol-2(3H)-ones and 1,2,4-oxadiazole-5-thiol. (Figure presented.).
Rh(II)-Catalyzed Transannulation of 1,2,4-Oxadiazole Derivatives with 1-Sulfonyl-1,2,3-triazoles: Regioselective Synthesis of 5-Sulfonamidoimidazoles
Strelnikova, Julia O.,Rostovskii, Nikolai V.,Starova, Galina L.,Khlebnikov, Alexander F.,Novikov, Mikhail S.
, p. 11232 - 11244 (2018/09/06)
An effective method for the synthesis of fully substituted 5-sulfonamidoimidazoles by Rh(II)-catalyzed transannulation of 1,2,4-oxadiazole derivatives with N-sulfonyl-1,2,3-triazoles is reported. The reaction works well with both aromatic 1,2,4-oxadiazoles and 1,2,4-oxadiazol-5-ones providing a flexible approach to N-(alkoxy/amino)carbonyl- and N-alkyl-substituted imidazoles. Both the disclosed reactions are completely regioselective and provide the first examples of a carbenoid-mediated transformation of N,N,O-heterocycles.
Oxadiazolone-Enabled Synthesis of Primary Azaaromatic Amines
Yu, Xiaolong,Chen, Kehao,Yang, Fan,Zha, Shanke,Zhu, Jin
supporting information, p. 5412 - 5415 (2016/11/06)
Despite their tremendous synthetic and pharmaceutical utility, primary azaaromatic amines remain elusive for access based on a generally applicable C-H functionalization strategy. An oxadiazolone-enabled approach is reported for convenient entry into N-unsubstituted 1-aminoisoquinolines through Co(III)-catalyzed redox-neutral, step-, atom-, and purification-economic C-H functionalization with alkynes. A 15N labeling experiment reveals the effectiveness of both oxadiazolone N atoms as directing sites. The installed primary amine can be harnessed as a synthetically useful handle for attachment of divergent appendages.
Synthesis of 2-(2-methyltetrazol-5-yl)-2,2-dinitroacetonitrile and its reaction with substituted nitrile N-oxides
Abdelrakhim,Tyrkov,Yurtaeva
, p. 280 - 284 (2014/04/17)
A procedure of synthesis of 2-(2-methyltetrazol-5-yl)-2,2- dinitroacetonitrile has been developed and its reaction with substituted nitrile N-oxides has been investigated, proceeding by the mechanism of 1,3-dipolar cycloaddition and affording 2-methyl-5-[(1,2,4-oxadiazol-5-yl)(dinitro)methyl]- 2H-tetrazoles. The latter react with KOH in ethanol forming the potassium salt of 2-methyltetrazol-5-yldinitromethane and substituted 5-hydroxy-1,2,4- oxadiazoles.
NH-acidities and Hammett correlation of 3-para substituted phenyl-1,2,4-oxadiazol-5(4H)-ones and 1,2 λ43,5-oxathiadiazole 2-oxides in nonaqueous media
Dueruest, Nedime,Dueruest, Yasar,Goezlukaya, Emine Oezge
, p. 56 - 62 (2014/02/14)
NH acidities of some 3-(p-substitutedphenyl)-1,2,4-oxadiazol-5(4H)-ones and 4-(p-substitutedphenyl)-1,2 λ43,5-oxathiadiazole 2-oxides were determined in methanol by means of potentiometric titration with sodium methoxide. pKa values of the titl
Kinetics of base-catalysed hydrolysis and cyclisation of substituted acetamide and benzamide O-(phenoxycarbonyl)oximes
Mindl, Jaromir,Kavalek, Jaromir,Strakova, Helena,Sterba, Vojeslav
, p. 1641 - 1653 (2007/10/03)
The reaction kinetics of acetamide O-(4-nitrophenoxycarbonyl)oxime have been studied in aqueous buffers at pH 2-11. At pH > 9, the pH dependence of kobs is linear with slope 1, the cyclisation to 3-methyl-1,2,4-oxadiazol-5(4H)-one and 4-nitrophenol being the only reaction. At pH obs on pH has been used to determine the rate equation and to propose the reaction mechanism. The cyclisation kinetics of substituted benzamide O-(phenoxycarbonyl)oximes have been studied in the pH range from 9.25 to 11. The reaction mechanism has been proposed based on the ρ constants found. In the first reaction step, the proton is split off from the NH2 group; the subsequent, rate-limiting step involves simultaneous N-C bond formation and C-O bond splitting.
REACTION OF BENZAMIDE OXIME DERIVATIVES WITH CHLOROCARBONYLSULFENYL CHLORIDE
Kawashima, Etsuko,Ando, Yuko,Takada, Toyozo,Tabei, Katsumi
, p. 181 - 190 (2007/10/02)
Benzamide oxime derivatives (1) were reacted with chlorocarbonylsulfenyl chloride (2) in the presence of a base as a catalyst to afford 3-aryl-4,5-dihydro-1,2,4-thiadiazol-5-one (3), 3-aryl-4,5-dihydro-1,2,4-oxadiazol-5-one (4) and di(benzamide) O,O'-carboxime (5) derivatives in moderate yields.The reaction of N-ethyl-p-toluamide oxime (7) with 2 gave 4-ethyl-4,5-dihydro-3-(p-tolyl)-1,2,4-thiadiazol-5-one (8) and 4-ethyl-4,5-dihydro-3-(p-tolyl)-1,2,4-oxadiazol-5-one (9).
Cyclization of O-Acetoacetylbenzamide Oxime Derivatives
Tabei, Katsumi,Kawashima, Etsuko,Takada, Toyozo,Kato, Tetsuzo
, p. 336 - 340 (2007/10/02)
O-Acetoacetylbenzamide oxime derivatives (2) were prepared from benzamide oxime derivatives (1) and diketene at low temperature in almost quantitative yields.Cyclization of 2 in the presence of a strong base proceeded with elimination of acetone to afford 3-aryl-1,2,4-oxadiazolin-5-one derivatives (4) in 77-95percent yields.However, in the cases of the o-, m-, and p-nitrobenzamide oxime derivatives (2f-h), the reaction proceeded with dehydration even in the presence of a strong base to afford 5-acetonyl-3-aryl-1,2,4-oxadiazole derivatives (3f-h) in moderate yields.Possible mechanisms of these cyclization are discussed.
