- Stereoselective synthesis of Z alkenyl halides via Julia olefination
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Julia olefination between α-halomethyl sulfones and a variety of aldehydes afforded alkenyl halides in good to excellent yields with high E/Z stereoselectivities. Sulfones were readily prepared in two or three steps from commercially available reagents in good yields. Optimization revealed that the nature of the solvent, the base, and the additive were crucial to obtain the desired alkenyl halides.
- Lebrun, Marie-Eve,Le Marquand, Paul,Berthelette, Carl
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- Synthesis of some derivatives of pyrimido[5,4-e]tetrazolo[5,1-c][1,2,4]triazine; a novel heterocyclic system
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Several new derivatives of pyrimido[5,4-e]tetrazolo[5,1-c][1,2,4]triazine have been synthesised through the reaction of 5-hydrazinyl-1H-tetrazole with 5-bromo-2,4-dichloro-6-methylpyrimidine in CHCl3 solution at ambient conditions. Further trea
- Noorolahian, Negin,Shiri, Ali
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- Metal-Free Aminomethylation of Aromatic Sulfones Promoted by Eosin Y
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A metal-free α-aminomethylation of heteroaryls promoted by eosin Y under green light irradiation is reported. A large variety of α-trimethylsilylamines as precursor of α-aminomethyl radical species were engaged to functionalize sulfonyl-heteroaryls following a Homolytic Aromatic Substitution (HAS) pathway. This method has provided a range of α-aminoheteroaryl compounds including a functionalized natural product. The mechanism of this late-stage functionalization of aryls was investigated and suggests the formation of a sulfonyl radical intermediate over a reductive quenching cycle.
- Thierry, Thibault,Pfund, Emmanuel,Lequeux, Thierry
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supporting information
p. 14826 - 14830
(2021/10/01)
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- Ring Expansion Fluorination of Unactivated Cyclopropanes Mediated by a New Monofluoroiodane(III) Reagent
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Herein, we report a new strategy for carbon?carbon bond scission and intramolecular ring expansion fluorination of unactivated cyclopropanes, which was accomplished with a new hypervalent fluoroiodane(III) reagent 1. This novel method delivers medicinally relevant 4-fully substituted fluoropiperidines in moderate to high yields with excellent regio- and diastereoselectivity. Reagent 1, which has an N-acetylbenziodazole framework, was readily synthesized via three steps in 76 % overall yield and was characterized by NMR spectroscopy and X-ray crystallography. Owing to the presence of a secondary I???O bonding interaction between the λ3-iodane atom and the carbonyl oxygen of the acetyl group of the N-acetylbenziodazole framework, 1 has excellent stability and can be stored at ambient temperature for 6 months without any detectable decomposition. Density functional theory calculations and experimental studies showed that the reaction proceeds via a carbocation intermediate that readily combines with a fluoride ion to generate the product.
- Chen, Ze,Du, Feng-Huan,Hu, Ze-Nan,Jia, Meng-Cheng,Ren, Jing,Zhang, Chi
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supporting information
p. 24171 - 24178
(2021/10/08)
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- Alkylation of thiols with trichloroacetimidates under neutral conditions
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Trichloroacetimidates are displaced with thiols to form the corresponding sulfides without the need for an added acid or base by simply heating the reactants in refluxing THF. This operationally simple procedure provides the corresponding sulfides in excellent yields with only the formation of the neutral trichloroacetamide as the side product. The imidate may also be formed in situ, allowing for a direct method for the formation of sulfides from alcohols. This reaction provides a general method for the synthesis of a variety of sulfides from inexpensive and readily available alcohol starting materials.
- Duffy, Brian C.,Howard, Kyle T.,Chisholm, John D.
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supporting information
p. 3301 - 3305
(2015/03/04)
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- 1-Substituted-5-[(3,5-dinitrobenzyl)sulfanyl]-1H-tetrazoles and their isosteric analogs: A new class of selective antitubercular agents active against drug-susceptible and multidrug-resistant mycobacteria
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In this work, a new class of highly potent antituberculosis agents, 1-substituted-5-[(3,5-dinitrobenzyl)sulfanyl]-1H-tetrazoles and their oxa and selanyl analogs, is described. The minimal inhibitory concentration (MIC) values reached 1 μM (0.36-0.44 μg/mL) against Mycobacterium tuberculosis CNCTC My 331/88 and 0.25-1 μM against six multidrug-resistant clinically isolated strains of M. tuberculosis. The antimycobacterial effects of these compounds were highly specific because they were ineffective against all eight bacterial strains and eight fungal strains studied. Furthermore, these compounds exhibited low in vitro toxicity in four mammalian cell lines (IC50 > 30 μM). We also examined the structure-activity relationships of the compounds, particularly the effects on antimycobacterial activity of the number and position of the nitro groups, the linker between tetrazole and benzyl moieties, and the tetrazole itself. Relatively high variability of substituent R 1 on the tetrazole in the absence of negative effects on antimycobacterial activity allows further structural optimization with respect to toxicity and the ADME properties of the 1-substituted-5-[(3,5-dinitrobenzyl) sulfanyl]-1H-tetrazoles lead compounds.
- Karabanovich, Galina,Roh, Jaroslav,Smutny, Tomá?,Něme?ek, Jan,Vicherek, Petr,Stola?íková, Ji?ina,Vejsová, Marcela,Dufková, Ida,Vávrová, Kate?ina,Pávek, Petr,Klime?ová, Věra,Hrabálek, Alexandr
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p. 324 - 340
(2014/06/24)
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- Regioselective formal hydroamination of styrenes with 1-phenyl-1 H -tetrazole-5-thiol
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1-Phenyl-1H-tetrazole-5-thiol 1 (PT-thiol) is employed in a unique Markovnikov-selective formal hydroamination of styrenyl compounds in the presence of catalytic amounts of Ga(OTf)3. This gives rise to the formation of tetrazolothione moieties
- Savolainen, Markku A.,Han, Xinping,Wu, Jimmy
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p. 4349 - 4351
(2015/01/09)
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- Rapid, stable, chemoselective labeling of thiols with Julia- Kocienski-like reagents: A serum-stable alternative to maleimide-based protein conjugation
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Exquisite chemoselectivity for cysteine has been found for methylsulfonylphenyloxadiazole compounds under various buffer conditions. Furthermore, the resulting protein conjugates have superior stability to cysteine-maleimide conjugates in human plasma (HS
- Toda, Narihiro,Asano, Shigehiro,Barbas, Carlos F.
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supporting information
p. 12592 - 12596
(2013/12/04)
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- A facile one-pot synthesis of 1-substituted tetrazole-5-thiones and 1-substituted 5-alkyl(aryl)sulfanyltetrazoles from organic isothiocyanates
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Treatments of organic isothiocyanates (R-NCS) with NaN3 in the presence of pyridine in water at room temperature gave corresponding various organic tetrazole-thiones, [S=CN4(R)] (R = alkyl or aryl). Isolated products are obtained as white or yellow solids in good yields (76-97%). The molecular structure by X-ray diffraction study for one of products shows the proposed formation. In addition, one-pot synthesis of 1- substituted 5-alkyl(or aryl)sulfanyltetrazoles has been demonstrated. Addition of alkyl or aryl halides into the mixture of organic isothiocyanates, NaN3, and pyridine in water at room temperature exclusively formed 1- substituted 5-alkyl(or aryl)sulfanyltetrazoles (S-derivatives) in high yields.
- Han, Sam Yong,Lee, Je Woo,Kim, Hee-Jung,Kim, Yong-Joo,Lee, Soon W.,Gyoung, Young Soo
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experimental part
p. 55 - 59
(2012/03/09)
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- SH-methylation of SH-containing heterocycles with dimethyl carbonate via phase-transfer catalytic reaction
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A reaction of SH-containing heterocycles with dimethyl carbonate (DMC) in the presence of K2CO3 and tetrabutylammonium bromide (Bu4NBr) gave heteroaryl methyl thioethers in 44-93% yields. The reaction was carried out under mild conditions. This method provided a useful synthetic method for preparation of various heteroaryl methyl thioethers without the use of toxic methylic halides or dimethyl sulfate.
- Xie, Jian-Gang,Quan, Jing,Li, Shu-Bai,Zheng, Yan,Zhu, Li-Min
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experimental part
p. 871 - 878
(2011/04/22)
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- Ionic liquids - Promoted S-methylation of thiols utilizing dimethyl carbonate
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Convenient and efficient S-methylation of mercaptans or thiophenols occurs with dimethyl carbonate (DMC) in room temperature ionic liquids (RTILs) [Bmim]Cl. [Bmim]Cl can be recycled in four subsequent runs with only a gradual decrease in activity. A possible mechanism of this transformation is also discussed. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. Copyright Taylor & Francis Group, LLC.
- Xie, Jiangang,Wu, Chengyao,Christopher, Branford White,Quan, Jing,Zhu, Limin
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experimental part
p. 31 - 37
(2011/04/22)
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- Practical synthesis of β-acyl and β-alkoxycarbonyl heterocyclic sulfones
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A short and efficient synthesis for β-acyl and β-alkoxycarbonyl heterocyclic sulfones containing benzothiazol (BT) and phenyltetrazol (PT) heterocyclic core is presented here. The method seems to be general and provides the desired C-nucleophiles in very good to excellent yields from readily available starting materials.
- Pospisil, Jiri,Sato, Hitoshi
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supporting information; experimental part
p. 2269 - 2272
(2011/06/11)
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- Tetrazoles: XXXIX. Alkylation of 1-substituted tetrazole-5-thiones under conditions of phase-transfer catalysis
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Phase-transfer alkylation of tetrazole-5-thiones with methyl iodide in the system liquid-liquid occurs exclusively at the sulfur atom, regardless of the substituent on N1. Electron-donor substituents in the substrate enhance their reactivity.
- Koreneva,Farsa,Hrabalek,Koldobskii
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p. 1820 - 1823
(2007/10/03)
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- Tetrazoles. XXXI. Phase-Transfer Reactions of 1-Substituted Tetrazole-5-thiones and Their Derivatives
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Alkylation of 1-substituted tetrazole-5-thiones under conditions of phase-transfer catalysis in the two-phase system liquid-liquid proceeds regioselectively at the sulfur atom, regardless of the alkylating agent and phase-transfer catalyst. Phase-transfer oxidation of the 5-alkylthiotetrazoles thus obtained by potassium permanganate is a convenient method for preparation of 5-alkylsulfonyltetrazoles which can be used to synthesize functionally substituted tetrazoles.
- Gol'tsberg,Koldobskii
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p. 1194 - 1201
(2007/10/03)
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- Tetrazoles. XXXII. Reactions of 1-R-Tetrazole-5-Thiones and Their Derivatives under Conditions of Phase Transfer Catalysis. Selection of Phase Transfer Catalyst
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Among the six investigated catalysts of phase transfer the most effective at alkylation of 1-phenyltetrazole-5-thione and oxidation of 5-methylthio-phenyltetrazole turned out to be the benzyldimetyhyl(5-methoxycarbonylpentyl)ammonium bromide. The directio
- Gol'tsberg,Grabalek,Farsa,Krebs,Dolezhal,Koldobsky
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p. 1367 - 1369
(2007/10/03)
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