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Shunyi Wang - One of the best experts on this subject based on the ideXlab platform.
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cascade trisulfur Radical Anion s3 addition electron detosylation process for the synthesis of 1 2 3 thiadiazoles and isothiazoles
Journal of Organic Chemistry, 2018Co-Authors: Bei-bei Liu, Hui-wen Bai, Huan Liu, Shunyi WangAbstract: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.
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Cascade Trisulfur Radical Anion (S3•–) Addition/Electron Detosylation Process for the Synthesis of 1,2,3-Thiadiazoles and Isothiazoles
2018Co-Authors: Bei-bei Liu, Hui-wen Bai, Huan Liu, Shunyi WangAbstract: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
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the involvement of the trisulfur Radical Anion in electron catalyzed sulfur insertion reactions facile synthesis of benzothiazine derivatives under transition metal free conditions
Chemical Science, 2016Co-Authors: Jiajia Cao, Shunyi WangAbstract:An efficient and practical synthesis of benzothiazine by K2S initiated sulfur insertion reaction with enaminones via electron catalysis is developed. This protocol provides a new, environment-friendly and simple strategy to construct benzothiazine derivatives via formation of two C–S bonds under transition metal-free, additive-free and oxidant-free conditions. K2S not only provides the sulfur insertion source, but also ignites the reaction through the formation of a trisulfur Radical Anion and electrons in DMF.
Muralee Murugesu - One of the best experts on this subject based on the ideXlab platform.
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strong ferromagnetic exchange coupling in a niii4 cluster mediated through an air stable tetrazine based Radical Anion
Chemical Communications, 2017Co-Authors: Maykon A Lemes, Gabriel Brunet, Amelie Pialat, Liviu Ungur, Ilia Korobkov, Muralee MurugesuAbstract:A planar tetradentate 3,6-bis(2-pyrimidyl)-1,2,4,5-tetrazine (BpymTz) templating chelate affords the formation of an unprecedented BpymTz˙- Radical Anion bridged {Ni} complex. Detailed magnetic measurements performed on the isolated air stable [Ni(BpymTz˙-)Cl6(DMF)8]Cl·0.5(H2O) compound reveal strong ferromagnetic NiII-BpymTz˙- interactions with a coupling constant of J = 98.84 cm-1.
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strong ferromagnetic exchange coupling in a ni cluster mediated through an air stable tetrazine based Radical Anion
Chemical Communications, 2017Co-Authors: Maykon A Lemes, Gabriel Brunet, Amelie Pialat, Liviu Ungur, Ilia Korobkov, Muralee MurugesuAbstract:A planar tetradentate 3,6-bis(2-pyrimidyl)-1,2,4,5-tetrazine (BpymTz) templating chelate affords the formation of an unprecedented BpymTz˙- Radical Anion bridged {Ni} complex. Detailed magnetic measurements performed on the isolated air stable [Ni(BpymTz˙-)Cl6(DMF)8]Cl·0.5(H2O) compound reveal strong ferromagnetic NiII-BpymTz˙- interactions with a coupling constant of J = 98.84 cm-1.
Kunio Awaga - One of the best experts on this subject based on the ideXlab platform.
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transition metal complexes and Radical Anion salts of 1 10 phenanthroline derivatives annulated with a 1 2 5 tiadiazole and 1 2 5 tiadiazole 1 1 dioxide moiety multidimensional crystal structures and various magnetic properties
Molecules, 2014Co-Authors: Yoshiaki Shuku, Kunio AwagaAbstract:Advances in the molecular variety and the elucidation of the physical properties of 1,10-phenanthroline annulated with 1,2,5-thiadiazole and 1,2,5-thiadiazole 1,1-dioxide moieties have been achieved, and are described herein. A 1,2,5-thiadiazole compound, [1,2,5]thiadiazolo[3,4-f][1,10]phenanthroline (tdap), was used as a ligand to create multidimensional network structures based on S•••S and S•••N intermolecular interactions. A 1,2,5-thiadiazole 1,1-dioxide compound, [1,2,5] thiadiazolo[3,4-f][1,10]phenanthroline, 1,1-dioxide (tdapO2), was designed to create a stable Radical Anion, as well as good network structures. Single crystal X-ray structure analyses revealed that transition metal complexes of tdap, and Radical Anion salts of tdapO2 formed multidimensional network structures, as expected. Two kinds of tdap iron complexes, namely [Fe(tdap)2(NCS)2] and [Fe(tdap)2(NCS)2]•MeCN exhibited spin crossover transitions, and their transition temperatures showed a difference of 150 K, despite their similar molecular structures. Magnetic measurements for the tdapO2 Radical Anion salts revealed that the magnetic coupling constants between neighboring Radical species vary from strongly antiferromagnetic (J = −320 K) to ferromagnetic (J = 24 K), reflecting the differences in their π overlap motifs.
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monovalent and mixed valent potassium salts of 1 2 5 thiadiazolo 3 4 f 1 10 phenanthroline 1 1 dioxide a Radical Anion for multidimensional network structures
Inorganic Chemistry, 2011Co-Authors: Yoshiaki Shuku, Rie Suizu, Kunio AwagaAbstract:A novel phenanthlorine derivative, [1,2,5]thiadiazolo[3,4-f][1,10]phenanthroline 1,1-dioxide (tdapO2), was prepared to act as a Radical-Anion building block for coordination polymers. The crystal structures and magnetic properties of the monovalent and mixed-valent Radical-Anion salts K·tdapO2 and K·(tdapO2)2 were elucidated and confirm the possibility of tdapO2 to act as a bridging ligand and its capability to exhibit magnetic ordering at 15 K.
Mario Fontana - One of the best experts on this subject based on the ideXlab platform.
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reactivity of hypotaurine and cysteine sulfinic acid toward carbonate Radical Anion and nitrogen dioxide as explored by the peroxidase activity of cu zn superoxide dismutase and by pulse radiolysis
Free Radical Research, 2014Co-Authors: Baseggio A Conrado, Laura Pecci, M Dangelantonio, Armida Torreggiani, Mario FontanaAbstract:AbstractHypotaurine and cysteine sulfinic acid are known to be readily oxidized to the respective sulfonates, taurine and cysteic acid, by several oxidative agents that may be present in biological systems. In this work, the relevance of both the carbonate Anion and nitrogen dioxide Radicals in the oxidation of hypotaurine and cysteine sulfinic acid has been explored by the peroxidase activity of Cu,Zn superoxide dismutase (SOD) and by pulse radiolysis. The extent of sulfinate oxidation induced by the system SOD/H2O2 in the presence of bicarbonate (CO3•– generation), or nitrite (•NO2 generation) has been evaluated. Hypotaurine is efficiently oxidized by the carbonate Radical Anion generated by the peroxidase activity of Cu,Zn SOD. Pulse radiolysis studies have shown that the carbonate Radical Anion reacts with hypotaurine more rapidly (k = 1.1 × 109 M−1s−1) than nitrogen dioxide (k = 1.6 × 107 M−1s−1). Regarding cysteine sulfinic acid, it is less reactive with the carbonate Radical Anion (k = 5.5 × 107 M−...
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reactivity of hypotaurine and cysteine sulfinic acid toward carbonate Radical Anion and nitrogen dioxide as explored by the peroxidase activity of cu zn superoxide dismutase and by pulse radiolysis
Free Radical Research, 2014Co-Authors: Baseggio A Conrado, Laura Pecci, M Dangelantonio, Armida Torreggiani, Mario FontanaAbstract:Hypotaurine and cysteine sulfinic acid are known to be readily oxidized to the respective sulfonates, taurine and cysteic acid, by several oxidative agents that may be present in biological systems. In this work, the relevance of both the carbonate Anion and nitrogen dioxide Radicals in the oxidation of hypotaurine and cysteine sulfinic acid has been explored by the peroxidase activity of Cu,Zn superoxide dismutase (SOD) and by pulse radiolysis. The extent of sulfinate oxidation induced by the system SOD/H2O2 in the presence of bicarbonate (CO3(•-) generation), or nitrite ((•)NO2 generation) has been evaluated. Hypotaurine is efficiently oxidized by the carbonate Radical Anion generated by the peroxidase activity of Cu,Zn SOD. Pulse radiolysis studies have shown that the carbonate Radical Anion reacts with hypotaurine more rapidly (k = 1.1 × 10(9) M(-1)s(-1)) than nitrogen dioxide (k = 1.6 × 10(7) M(-1)s(-1)). Regarding cysteine sulfinic acid, it is less reactive with the carbonate Radical Anion (k = 5.5 × 10(7) M(-1)s(-1)) than hypotaurine. It has also been observed that the one-electron transfer oxidation of both sulfinates by the Radicals is accompanied by the generation of transient sulfonyl Radicals (RSO2(•)). Considering that the carbonate Radical Anion could be formed in vivo at high level from bicarbonate, this Radical can be included in the oxidants capable of performing the last metabolic step of taurine biosynthesis. Moreover, the protective effect exerted by hypotaurine and cysteine sulfinate on the carbonate Radical Anion-mediated tyrosine dimerization indicates that both sulfinates have scavenging activity towards the carbonate Radical Anion. However, the formation of transient reactive intermediates during sulfinate oxidation by carbonate Anion and nitrogen dioxide Radical may at the same time promote oxidative reactions.
Jay L Zweier - One of the best experts on this subject based on the ideXlab platform.
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reactivity of superoxide Radical Anion with cyclic nitrones role of intramolecular h bond and electrostatic effects
Journal of the American Chemical Society, 2007Co-Authors: Frederick A Villamena, Christopher M Hadad, Shijing Xia, John K Merle, Robert Lauricella, Beatrice Tuccio, Jay L ZweierAbstract:Limitations exist among the commonly used cyclic nitrone spin traps for biological free Radical detection using electron paramagnetic resonance (EPR) spectroscopy. The design of new spin traps for biological free Radical detection and identification using EPR spectroscopy has been a major challenge due to the lack of systematic and rational approaches to their design. In this work, density functional theory (DFT) calculations and stopped-flow kinetics were employed to predict the reactivity of functionalized spin traps with superoxide Radical Anion (O2•-). Functional groups provide versatility and can potentially improve spin-trap reactivity, adduct stability, and target specificity. The effect of functional group substitution at the C-5 position of pyrroline N-oxides on spin-trap reactivity toward O2•- was computationally rationalized at the PCM/B3LYP/6-31+G(d,p)//B3LYP/6-31G(d) and PCM/mPW1K/6-31+G(d,p) levels of theory. Calculated free energies and rate constants for the reactivity of O2•- with model n...
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theoretical and experimental studies of the spin trapping of inorganic Radicals by 5 5 dimethyl 1 pyrroline n oxide dmpo 2 carbonate Radical Anion
Journal of Physical Chemistry A, 2006Co-Authors: Frederick A Villamena, Edward J Locigno, Antal Rockenbauer, Christopher M Hadad, Jay L ZweierAbstract:The carbon dioxide Radical Anion (CO2•-) is known to be generated in vivo through various chemical and biochemical pathways. Electron paramagnetic resonance (EPR) spin trapping with the commonly us...
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theoretical and experimental studies of the spin trapping of inorganic Radicals by 5 5 dimethyl 1 pyrroline n oxide dmpo 1 carbon dioxide Radical Anion
Journal of Physical Chemistry A, 2006Co-Authors: Frederick A Villamena, Edward J Locigno, Antal Rockenbauer, Christopher M Hadad, Jay L ZweierAbstract:The carbon dioxide Radical Anion (CO2•-) is known to be generated in vivo through various chemical and biochemical pathways. Electron paramagnetic resonance (EPR) spin trapping with the commonly us...