- Synthesis of a stereochemically defined 1,2-diazetine N,N′-dioxide and a study of its thermal decomposition
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(Chemical Equation Presented) Diazetine dioxide 1a has been synthesized in a single step via oxidation of meio-2,3-diphenyl-1,2-ethanediamine with dimethyldioxirane, albeit in low yield (7%). Thermal decomposition of 1a afforded predominantly either trans-stilbene or diphenyl glyoxime depending on solvent, temperature, and the presence of an amine catalyst. Reaction in chloroform at 69°C favored elimination of NO and formation of trans-stilbene. The stereospecific formation of trans-stilbene suggests a mechanism of decomposition in which C-N bond cleavage leads to a diradical intermediate stabilized by the phenyl group. Bond rotation followed by cleavage of the second C-N bond accounts for the trans-stilbene. At 25 °C in chloroform, while trans-stilbene was still the major product, some diphenyl glyoxime was also observed (4% yield). However, la as a solution in chloroform in the presence of Et3N, or 1a as a solution in DMSO-d6, afforded predominantly diphenyl glyoxime. These results are interpreted in terms of two closely competing reactions subject to the effects of entropic contributions.
- Breton, Gary W.,Oliver, Lindsey H.,Nickerson, Justine E.
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- Oxidation of: O -dioxime by (diacetoxyiodo)benzene: Green and mild access to furoxans
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Furoxan has been widely used in the field of high energy density materials because of its excellent properties such as high density, high standard enthalpy of formation and high nitrogen content. However, its existing synthesis methods are still restricted by the problems of difficult substrate preparation and manual handling of hazardous reagents. Herein, we disclosed a mild oxidation strategy to efficiently obtain furoxan derivatives starting from readily available o-dioxime substrates. This reaction features high functional group tolerance and easy scale-up, and has excellent regioselectivity for specific nonsymmetric o-dioximes. This method greatly reduces the safety risk and simplifies the operation process, and means that diversified furoxan derivatives can be easily accessed, thus paving the way for the wide application of furoxan derivatives. This journal is
- He, Chunlin,Pang, Siping,Zhang, Qi,Zhang, Xun,Zhao, Cheng
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p. 1489 - 1493
(2022/01/31)
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- Novel riboflavin-inspired conjugated bio-organic semiconductors
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Flavins are known to be extremely versatile, thus enabling routes to innumerable modifications in order to obtain desired properties. Thus, in the present paper, the group of bio-inspired conjugated materials based on the alloxazine core is synthetized using two efficient novel synthetic approaches providing relatively high reaction yields. The comprehensive characterization of the materials, in order to evaluate the properties and application potential, has shown that the modification of the initial alloxazine core with aromatic substituents allows fine tuning of the optical bandgap, position of electronic orbitals, absorption and emission properties. Interestingly, the compounds possess multichromophoric behavior, which is assumed to be the results of an intramolecular proton transfer.
- Richtar, Jan,Heinrichova, Patricie,Apaydin, Dogukan Hazar,Schmiedova, Veronika,Yumusak, Cigdem,Kovalenko, Alexander,Weiter, Martin,Sariciftci, Niyazi Serdar,Krajcovic, Jozef
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- Green and highly selective protocol for the synthesis of oximes
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A green and efficient protocol has been developed for the synthesis of either exclusively a monoxime or exclusively a dioxime from a host of 1,2-dicarbonyl compounds on silica.
- Ghosh, Pranab,Subba, Raju
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p. 529 - 532
(2013/11/06)
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- Synthesis and characterization of 2,3,5,6-tetraphenylpyrazine-N, N-dioxide: New nitrone dimer species
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The synthesis, characterization and physical properties of 2,3,5,6-tetraphenylpyrazine-N,N-dioxide presently are reported. A specific reduction mechanism of an oxime using zinc with NH4Cl to yield hydroxylamine was performed. This was followed by a condensation reaction with sulfuric acid that leads to 2,3,5,6-tetraphenylpyrazine-N,N-dioxide. The product was characterized by means of IR, UV,1H-NMR and13C-NMR spectroscopy which were complemented by theoretical computations. The Japan Institute of Heterocyclic Chemistry.
- Essa, Ali Hashem,Al-Shamkhani, Zeki A. Nasir,Jalbout, Abraham F.,Hameed, Ali Jameel
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experimental part
p. 2235 - 2242
(2011/04/17)
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- Titanium(III) Chloride Mediated Reduction of 1-Nitro-2-phenylethenes
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The reaction of 1-nitro-2-phenylethenes (β-nitrostyrenes) with aqueous titanium(III) chloride afforded substituted pyrroles in addition to the expected reduction products, oximes and carbonyl compounds. 2-Substituted 1-nitro-2-phenylethenes yielded divinylamine derivatives instead of pyrroles.The reaction mechanism has been rationalized by taking account of the electron transfer from titanium(III) species to the nitro olefines, followed by protonation, dimerization, cyclization, and/or hydrolysis.
- Sera, Akira,Fukumoto, Shoji,Tamura, Masako,Takabatake, Kiyoshi,Yamada, Hiroaki,Itoh, Kuniaki
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p. 1787 - 1791
(2007/10/02)
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