3920-15-8Relevant academic research and scientific papers
Transition Metal-Free Synthesis of Substituted Isothiazoles via Three-Component Annulation of Alkynones, Xanthate and NH4I
Li, Jian,Li, Jiaming,Ji, Xiaoliang,Liu, Qiang,Chen, Lu,Huang, Yubing,Li, Yibiao
supporting information, p. 1059 - 1068 (2020/12/15)
A protocol was described to access diverse isothiazoles with functionalization potential via transition metal-free three-component annulation of alkynones, potassium ethylxanthate (EtOCS2K) and ammonium iodide (NH4I). A sequential regioselective hydroamination/thiocarbonylation/intramolecular cyclization cascade achieved the efficient formation of consecutive C?N, C?S and N?S bonds in a one-pot process. (Figure presented.).
Synthesis of Isoselenazoles and Isothiazoles from Demethoxylative Cycloaddition of Alkynyl Oxime Ethers
Zhang, Zhu-Zhu,Chen, Rong,Zhang, Xiao-Hong,Zhang, Xing-Guo
, p. 632 - 642 (2020/12/22)
A general method for the synthesis of isoselenazoles and isothiazoles has been developed by the base-promoted demethoxylative cycloaddition of alkynyl oxime ethers using the cheap and inactive Se powder and Na2S as selenium and sulfur sources. This transformation features the direct construction of N-, Se-, and S-containing heterocycles through the formation of N-Se/S and C-Se/S bonds in one-pot reactions with excellent functional group tolerance.
Isothiazole derivative synthesis method
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Paragraph 0014; 0039-0049, (2021/01/25)
The invention relates to an isothiazole derivative synthesis method, which comprises: adopting alkynyl oxime ether as a reaction substrate, adopting sodium sulfide as a sulfur source, adopting sodiumbicarbonate as an alkali, adopting N, N-dimethylformamid
3, 5-disubstituted isothiazole compound and synthesis method and application thereof
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Paragraph 0034-0096, (2021/03/30)
The invention belongs to the technical field of organic synthesis, and discloses a 3, 5-disubstituted isothiazole compound and a synthesis method and applications thereof, the structural formula of the compound is represented by formula (II), and R1 and R2 respectively and independently represent hydrogen, a heterocyclic group, phenyl, a phenyl derivative or alkane. According to the invention, the3, 5-disubstituted isothiazole compound is synthesized by taking the acetylenic ketone compound as a raw material, heating and stirring under the condition of adding a solvent and carrying out one-pot reaction without catalysis of transition metal, and the synthesis is completed in one step without separating and purifying an intermediate in a conversion process except for a final product, so that industrial production is easy to realize, and capital and labor investment can be reduced for industrial production.
A novel and facile synthesis of 3,5-Disubstituted isothiozoles under metal free conditions using acetophenones and dithioesters
Nagaraju, Chaithra,Ashok, Swarup Hassan,Shamanth, Sadashivamurthy,Nagarakere, Sandhya C.,Sunilkumar, Makanahalli P.,Subbegowda, Rangappa Kanchugarakoppal,Mantelingu, Kempegowda
, p. 2647 - 2654 (2020/08/05)
A facile and conveniently simple new protocol is devised for the synthesis of 3,5-disubstituted and annulated isothiozoles under transition metal and catalyst free conditions utilizing easily available acetophenones, dithioesters and NH4OAc. This strategy involves C=O and C=S functionalization via sequential imine formation followed by intra molecular cyclization and aerial oxidation forming consecutive C?N and S?N bonds respectively in one pot. This protocol offers a low cost, user friendly, straight forward and widely applicable approach to 3,5-disubstituted isothiazoles.
Rhodium-Catalyzed Annulative Coupling of Isothiazoles with Alkynes through N-S Bond Cleavage
Mihara, Gen,Noguchi, Teppei,Nishii, Yuji,Hayashi, Yoshihiro,Kawauchi, Susumu,Miura, Masahiro
, p. 661 - 665 (2020/01/31)
A Rh(III)-catalyzed annulative coupling of 3,5-diarylisothiazoles and alkynes is reported. The N-S bond in the isothiazole ring acts as an internal oxidant to regenerate the Rh(III) species in combination with an external Cu(II) oxidant, and the corresponding 1:2 coupling products are obtained. The remarkable difference in the reaction outcome between isothiazoles and the relevant isoxazoles has been investigated by DFT calculations, revealing that the relative stability of the enolate intermediates dictates the product selectivity.
Cascade Trisulfur Radical Anion (S3?-) Addition/Electron Detosylation Process for the Synthesis of 1,2,3-Thiadiazoles and Isothiazoles
Liu, Bei-Bei,Bai, Hui-Wen,Liu, Huan,Wang, Shun-Yi,Ji, Shun-Jun
, p. 10281 - 10288 (2018/07/25)
Trisulfur radical anion (S3?-) mediated reactions with in situ formed azoalkenes and α,β-usaturated N-sulfonylimines for the construction of 1,2,3-thiadiazoles and isothiazoles has been developed. S3?- is in situ generated from potassium sulfide in DMF. These two approaches provide a new, safe, and simple way to construct 4-subsituted 1,2,3-thiadiazoles, 5-subsituted 1,2,3-thiadiazoles, and isothiazole in good yields. The reactions include the formation of the new C-S and N-S bonds via S3?- addition and electron detosylation under mild conditions.
A stereoselective thiocyanate conjugate addition to electron deficient alkynes and concomitant cyclization to N,S-heterocycles
Dwivedi, Vikas,Rajesh, Manda,Kumar, Ravi,Kant, Ruchir,Sridhar Reddy, Maddi
, p. 11060 - 11063 (2017/10/13)
A regio- and stereoselective thiocyanate addition to ynones is achieved using KSCN in AcOH at 70 °C. The reaction is extendable to ynals, ynesulfones, ynoic acids and ynoates. Adducts from ynones were readily transformed into thiazine-2-thione derivatives under slightly modified reaction conditions. In contrast, thiocyanated adducts from ynamides underwent an in situ decyanative amido cyclization towards isothiazolones. None of these events needed any transition metal or catalyst, attaining a high synthetic value.
The conversion of isothiazoles into pyrazoles using hydrazine
Ioannidou, Heraklidia A.,Koutentis, Panayiotis A.
experimental part, p. 7023 - 7037 (2009/12/06)
The conversion of isothiazoles into pyrazoles on treatment with hydrazine is investigated. The influence of various C-3, C-4 and C-5 isothiazole substituents and some limitations of this ring transformation are examined. When the isothiazole C-3 substituent is a good nucleofuge, 3-aminopyrazoles are obtained. However, when the 3-substituent is not a leaving group it is retained in the pyrazole product. Treatment of 4-bromo-3-chloro-5-phenylisothiazole 56 or 3-chloro-4,5-diphenylisothiazole 57 with anhydrous hydrazine at ca. 200 °C for a few minutes gives the corresponding 3-hydrazinoisothiazoles 61 and 64 respectively in high yields; the stability of these new hydrazines is investigated. 5,5′-Diphenyl-3,3′-biisothiazole-4,4′-dicarbonitrile 78 reacts with hydrazine to give 5,5′-diphenyl-3,3′-bi(1H-pyrazole)-4,4′-dicarbonitrile 79. Methylhydrazine reacts with 3-chloro-5-phenylisothiazole-4-carbonitrile 1 to give 3-(1-methylhydrazino)-5-phenylisothiazole-4-carbonitrile 83 and 3-amino-1-methyl-5-phenylpyrazole-4-carbonitrile 84. All products are fully characterised and rational mechanisms for the isothiazole into pyrazole transformation are proposed.
3,4,5-Triarylisothiazoles via C-C coupling chemistry
Christoforou, Irene C.,Koutentis, Panayiotis A.
, p. 1381 - 1390 (2008/01/03)
The regiocontrolled preparation of triarylisothiazoles is presented. 3-Halo-5-phenylisothiazole-4-carbonitriles, 1 (hal = Cl) and 18 (hal = I), are converted into the corresponding 4-bromo derivatives 5 (3-hal = Cl) and 24 (3-hal = I) via a Hunsdiecker strategy while the 4-iodo analogues 7 (3-hal = Cl) and 22 (3-hal = I) are prepared via a Hoffmann and Sandmeyer strategy. Regioselective Suzuki, Stille and Negishi reactions occur at C-4 with both the 4-bromo- and 4-iodoisothiazoles 5 and 7, the latter being more reactive than the former. 3-Iodoisothiazoles 22 and 24 fail to give regiocontrolled Suzuki, Stille or Negishi couplings, however, 4-bromo-3-iodo-5-phenylisothiazole 24 gives the regiospecific palladium catalysed Ullmann-type reaction product 3,3′-bi(4-bromo-5-phenylisothiazole) 25. Alkali hydrolysis of 3-chloro-4,5-diphenylisothiazole 8 gives the 3-hydroxy analogue 12 which is converted into 3-bromo-4,5-diphenylisothiazole 13 with POBr3. 3-Bromoisothiazole 13 reacts with phenylzinc chloride to give 3,4,5-triphenylisothiazole 17 but fails to undergo effective Suzuki or Stille couplings. 3,5-Diphenylisothiazole-4-carbonitrile 26 is converted into the 4-bromo- and 4-iodo-3,5-diphenylisothiazoles 30 and 34 both of which are effective for Suzuki and Stille couplings. A series of triarylisothiazoles are prepared in this manner and fully characterised. This journal is The Royal Society of Chemistry.
