The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Takashi Hayashita - One of the best experts on this subject based on the ideXlab platform.
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preparation and electrochemical properties of novel cyclic dinuclear acetylacetonato ruthenium complexes doubly bridged with sulfur and or Disulfur
Inorganica Chimica Acta, 2011Co-Authors: Akira Endo, Hitomi Tsuboya, Natsumi Fujita, Yasuyuki Ito, Takeshi Hashimoto, Takashi HayashitaAbstract:Abstract A novel cyclic dinuclear acetylacetonato ruthenium complex doubly bridged with sulfur and/or Disulfur at the γ-position of acetylacetonato ligand has been obtained by two different synthetic methods. The molecular structure of the dinuclear complex has been determined by single crystal X-ray diffraction study. Other two cyclic dinuclear β-diketonato ruthenium complexes were also prepared in good yields by the reaction of single bridged dinuclear complexes as starting materials with Disulfur dichloride. The cyclic voltammograms of all the dinuclear complexes exhibit two one-electron reduction and oxidation waves in acetonitrile (AN) and dichloromethane (DM). The comproportionation constants (Kc) for mixed-valence state of both RuII/RuIII and RuIII/RuIV were evaluated in both solvents at 25 or −30 °C. The values of both Kc (RuII/RuIII) and log10 Kc (RuIII/RuIV) for double bridged complex are large compared to those of corresponding single bridged complexes. This fact was rationally explained by the double bridging effect caused by the spread of electronic communication and also demonstrated the usefulness of the double bridged dinuclear complexes.
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Preparation and electrochemical properties of novel cyclic dinuclear acetylacetonato ruthenium complexes doubly bridged with sulfur and/or Disulfur
Inorganica Chimica Acta, 2011Co-Authors: Akira Endo, Hitomi Tsuboya, Natsumi Fujita, Yasuyuki Ito, Takeshi Hashimoto, Takashi HayashitaAbstract:Abstract A novel cyclic dinuclear acetylacetonato ruthenium complex doubly bridged with sulfur and/or Disulfur at the γ-position of acetylacetonato ligand has been obtained by two different synthetic methods. The molecular structure of the dinuclear complex has been determined by single crystal X-ray diffraction study. Other two cyclic dinuclear β-diketonato ruthenium complexes were also prepared in good yields by the reaction of single bridged dinuclear complexes as starting materials with Disulfur dichloride. The cyclic voltammograms of all the dinuclear complexes exhibit two one-electron reduction and oxidation waves in acetonitrile (AN) and dichloromethane (DM). The comproportionation constants (Kc) for mixed-valence state of both RuII/RuIII and RuIII/RuIV were evaluated in both solvents at 25 or −30 °C. The values of both Kc (RuII/RuIII) and log10 Kc (RuIII/RuIV) for double bridged complex are large compared to those of corresponding single bridged complexes. This fact was rationally explained by the double bridging effect caused by the spread of electronic communication and also demonstrated the usefulness of the double bridged dinuclear complexes.
Oleg A. Rakitin - One of the best experts on this subject based on the ideXlab platform.
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8-(Pyrimidin-2-yl)-1,2,3,4,5,6,7,8-heptathiazocane
Molbank, 2019Co-Authors: V. A. Ogurtsov, Oleg A. RakitinAbstract:Heptasulfur imides substituted by hereterocycle may be of interest as biologically active compounds. In this communication, the reaction of pyrimidin-2-amine 1 with Disulfur dichloride was carefully investigated to give 8-(pyrimidin-2-yl)-1,2,3,4,5,6,7,8-heptathiazocane in good yield. The structure of the newly synthesized compound was established by means of elemental analysis, high resolution mass-spectrometry, 1H, 13C NMR and IR spectroscopy and mass-spectrometry.
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Abnormally Mild Synthesis of Bis(dithiolo)pyrroles from 2,5-Dimethylpyrroles
Organic letters, 2005Co-Authors: Stanislav A. Amelichev, Oleg A. Rakitin, Lidia S. Konstantinova, Rinat R. Aysin, Natalia V. Obruchnikova, Charles W. ReesAbstract:Treatment of N-substituted 2,5-dimethylpyrroles 2 with an equilibrated mixture of Disulfur dichloride and DABCO in chloroform at 0 °C gives pentathiepinopyrroles 3 in moderate yields; further react...
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Unprecedented conversion of triethylamine and Disulfur dichloride into a thienopentathiepin and a heptathiocane.
Organic letters, 2003Co-Authors: Lidia S. Konstantinova, Oleg A. Rakitin, Charles W. Rees, Ljudmila I. Souvorova, Denis G. Golovanov, Konstantin A. LyssenkoAbstract:In a remarkable cascade reaction, triethylamine is converted into the thienopentathiepin 2a and the heptathiocane 3a by a preequilibrated solution of Disulfur dichloride and DABCO in chloroform.
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New heterocyclic materials
Proceedings of The 4th International Electronic Conference on Synthetic Organic Chemistry, 2000Co-Authors: Tomás Torroba, Oleg A. Rakitin, Charles W. ReesAbstract:The preparation of new heterocyclic systems by conventional ways is normally a hard work that implies many synthetic steps and expensive starting materials. Even more, many heterocyclic systems, being predictably stable, are impossible to be prepared because the synthetic approach simply does not exist. There is a very different approach to get new heterocyclic systems that uses simple organic starting materials (tertiary amines, alicyclic oximes) bearing a nucleophilic nitrogen which generates reactive intermediates, subsequently trapped by a inorganic reagent, Disulfur dichloride (S2Cl2). In general, trapping of intermediates is followed by extensive dehydrogenation and chlorination to give new intermediates that can be trapped by selected nucleophiles on the way to stable final products.1-2 A good combination of reagents and reaction sequences permits the preparation of heterocycles that imply up to fifteen different steps all working sequentially in a one-pot reaction. The best example of this chemistry is the reaction of N-ethyldiisopropylamine (Hunig’s base), with Disulfur dichloride.3-4 The first step is a slow oxidation of the amine to an immonium salt by a combination of Disulfur dichloride and DABCO (diazabicyclo[2.2.2]octane).
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One-pot synthesis of new liquid crystalline indeno heterocyclic materials
Chemical Communications, 1999Co-Authors: Lidia S. Konstantinova, Oleg A. Rakitin, Charles W. Rees, Ljudmila I. Souvorova, Andrew J. P. White, David J. Williams, Tomás TorrobaAbstract:Disulfur dichloride converts 1-(dicyanomethylene)indane 3 into the methyleneindene 4 and the red indeno-1,2-thiazine 5; it also converts inden-3-ylacetic acid 7 into methyleneindenes 8 and 9, dithiolone 10 and the deep purple thiophenone 11; upon melting crystals of 4 and 11 are strongly birefringent and 5 exhibits thermochromicity; mechanisms are outlined for the novel transformations and X-ray crystal structures for 5 and 10 are analysed.
Akira Endo - One of the best experts on this subject based on the ideXlab platform.
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preparation and electrochemical properties of novel cyclic dinuclear acetylacetonato ruthenium complexes doubly bridged with sulfur and or Disulfur
Inorganica Chimica Acta, 2011Co-Authors: Akira Endo, Hitomi Tsuboya, Natsumi Fujita, Yasuyuki Ito, Takeshi Hashimoto, Takashi HayashitaAbstract:Abstract A novel cyclic dinuclear acetylacetonato ruthenium complex doubly bridged with sulfur and/or Disulfur at the γ-position of acetylacetonato ligand has been obtained by two different synthetic methods. The molecular structure of the dinuclear complex has been determined by single crystal X-ray diffraction study. Other two cyclic dinuclear β-diketonato ruthenium complexes were also prepared in good yields by the reaction of single bridged dinuclear complexes as starting materials with Disulfur dichloride. The cyclic voltammograms of all the dinuclear complexes exhibit two one-electron reduction and oxidation waves in acetonitrile (AN) and dichloromethane (DM). The comproportionation constants (Kc) for mixed-valence state of both RuII/RuIII and RuIII/RuIV were evaluated in both solvents at 25 or −30 °C. The values of both Kc (RuII/RuIII) and log10 Kc (RuIII/RuIV) for double bridged complex are large compared to those of corresponding single bridged complexes. This fact was rationally explained by the double bridging effect caused by the spread of electronic communication and also demonstrated the usefulness of the double bridged dinuclear complexes.
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Preparation and electrochemical properties of novel cyclic dinuclear acetylacetonato ruthenium complexes doubly bridged with sulfur and/or Disulfur
Inorganica Chimica Acta, 2011Co-Authors: Akira Endo, Hitomi Tsuboya, Natsumi Fujita, Yasuyuki Ito, Takeshi Hashimoto, Takashi HayashitaAbstract:Abstract A novel cyclic dinuclear acetylacetonato ruthenium complex doubly bridged with sulfur and/or Disulfur at the γ-position of acetylacetonato ligand has been obtained by two different synthetic methods. The molecular structure of the dinuclear complex has been determined by single crystal X-ray diffraction study. Other two cyclic dinuclear β-diketonato ruthenium complexes were also prepared in good yields by the reaction of single bridged dinuclear complexes as starting materials with Disulfur dichloride. The cyclic voltammograms of all the dinuclear complexes exhibit two one-electron reduction and oxidation waves in acetonitrile (AN) and dichloromethane (DM). The comproportionation constants (Kc) for mixed-valence state of both RuII/RuIII and RuIII/RuIV were evaluated in both solvents at 25 or −30 °C. The values of both Kc (RuII/RuIII) and log10 Kc (RuIII/RuIV) for double bridged complex are large compared to those of corresponding single bridged complexes. This fact was rationally explained by the double bridging effect caused by the spread of electronic communication and also demonstrated the usefulness of the double bridged dinuclear complexes.
Tomás Torroba - One of the best experts on this subject based on the ideXlab platform.
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New chemistry of bis[1,2]dithiolo[1,4]thiazines and bis[1,2]dithiolopyrroles
Arkivoc, 2002Co-Authors: Susana Barriga, Nuria García, Carlos F. Marcos, Ana G. Neo, Tomás TorrobaAbstract:The new long-chain or branched-chain N-alkyl bisdithiolothiazines 2a,b, 3a,c, and 4a,c have been prepared by the appropriate one-pot reaction of the corresponding N- alkyldiisopropylamines and Disulfur dichloride. The bisdithiolopyrroles 5a-f were obtained by thermal sulfur extrusion from their corresponding bisdithiolothiazines or by an alternative and faster method consisting of S-oxidation by dimethyldioxyrane and SO extrusion. The cycloadditions of a bisdithiolothiazine ketothione and benzyne or p-tolylsulfonylacetylene were studied and the new cycloadducts 7 and 9 (Z +E) were characterized.
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New heterocyclic materials
Proceedings of The 4th International Electronic Conference on Synthetic Organic Chemistry, 2000Co-Authors: Tomás Torroba, Oleg A. Rakitin, Charles W. ReesAbstract:The preparation of new heterocyclic systems by conventional ways is normally a hard work that implies many synthetic steps and expensive starting materials. Even more, many heterocyclic systems, being predictably stable, are impossible to be prepared because the synthetic approach simply does not exist. There is a very different approach to get new heterocyclic systems that uses simple organic starting materials (tertiary amines, alicyclic oximes) bearing a nucleophilic nitrogen which generates reactive intermediates, subsequently trapped by a inorganic reagent, Disulfur dichloride (S2Cl2). In general, trapping of intermediates is followed by extensive dehydrogenation and chlorination to give new intermediates that can be trapped by selected nucleophiles on the way to stable final products.1-2 A good combination of reagents and reaction sequences permits the preparation of heterocycles that imply up to fifteen different steps all working sequentially in a one-pot reaction. The best example of this chemistry is the reaction of N-ethyldiisopropylamine (Hunig’s base), with Disulfur dichloride.3-4 The first step is a slow oxidation of the amine to an immonium salt by a combination of Disulfur dichloride and DABCO (diazabicyclo[2.2.2]octane).
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One-pot synthesis of new liquid crystalline indeno heterocyclic materials
Chemical Communications, 1999Co-Authors: Lidia S. Konstantinova, Oleg A. Rakitin, Charles W. Rees, Ljudmila I. Souvorova, Andrew J. P. White, David J. Williams, Tomás TorrobaAbstract:Disulfur dichloride converts 1-(dicyanomethylene)indane 3 into the methyleneindene 4 and the red indeno-1,2-thiazine 5; it also converts inden-3-ylacetic acid 7 into methyleneindenes 8 and 9, dithiolone 10 and the deep purple thiophenone 11; upon melting crystals of 4 and 11 are strongly birefringent and 5 exhibits thermochromicity; mechanisms are outlined for the novel transformations and X-ray crystal structures for 5 and 10 are analysed.
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Cyclopenta-1,2-dithioles and cyclopenta-1,2-thiazines from new molecular rearrangements
Chemical Communications, 1996Co-Authors: Oleg A. Rakitin, Charles W. Rees, Tomás TorrobaAbstract:The cyclobutanone oxime 6 reacts with Disulfur dichloride to give two unexpected 10π pseudoazulenes in low yield: the dark blue cyclopenta-1,2-dithiole 7 and the orange cyclopenta-1,2-thiazine 8; the benzo derivative 14 of this oxime gives the analogous benzo product 15 together with the methylene indene 16 in high yield; mechanisms based on abnormal Beckman rearrangements are proposed for the formation of all of these products.
Charles W. Rees - One of the best experts on this subject based on the ideXlab platform.
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Abnormally Mild Synthesis of Bis(dithiolo)pyrroles from 2,5-Dimethylpyrroles
Organic letters, 2005Co-Authors: Stanislav A. Amelichev, Oleg A. Rakitin, Lidia S. Konstantinova, Rinat R. Aysin, Natalia V. Obruchnikova, Charles W. ReesAbstract:Treatment of N-substituted 2,5-dimethylpyrroles 2 with an equilibrated mixture of Disulfur dichloride and DABCO in chloroform at 0 °C gives pentathiepinopyrroles 3 in moderate yields; further react...
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Unprecedented conversion of triethylamine and Disulfur dichloride into a thienopentathiepin and a heptathiocane.
Organic letters, 2003Co-Authors: Lidia S. Konstantinova, Oleg A. Rakitin, Charles W. Rees, Ljudmila I. Souvorova, Denis G. Golovanov, Konstantin A. LyssenkoAbstract:In a remarkable cascade reaction, triethylamine is converted into the thienopentathiepin 2a and the heptathiocane 3a by a preequilibrated solution of Disulfur dichloride and DABCO in chloroform.
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New heterocyclic materials
Proceedings of The 4th International Electronic Conference on Synthetic Organic Chemistry, 2000Co-Authors: Tomás Torroba, Oleg A. Rakitin, Charles W. ReesAbstract:The preparation of new heterocyclic systems by conventional ways is normally a hard work that implies many synthetic steps and expensive starting materials. Even more, many heterocyclic systems, being predictably stable, are impossible to be prepared because the synthetic approach simply does not exist. There is a very different approach to get new heterocyclic systems that uses simple organic starting materials (tertiary amines, alicyclic oximes) bearing a nucleophilic nitrogen which generates reactive intermediates, subsequently trapped by a inorganic reagent, Disulfur dichloride (S2Cl2). In general, trapping of intermediates is followed by extensive dehydrogenation and chlorination to give new intermediates that can be trapped by selected nucleophiles on the way to stable final products.1-2 A good combination of reagents and reaction sequences permits the preparation of heterocycles that imply up to fifteen different steps all working sequentially in a one-pot reaction. The best example of this chemistry is the reaction of N-ethyldiisopropylamine (Hunig’s base), with Disulfur dichloride.3-4 The first step is a slow oxidation of the amine to an immonium salt by a combination of Disulfur dichloride and DABCO (diazabicyclo[2.2.2]octane).
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One-pot synthesis of new liquid crystalline indeno heterocyclic materials
Chemical Communications, 1999Co-Authors: Lidia S. Konstantinova, Oleg A. Rakitin, Charles W. Rees, Ljudmila I. Souvorova, Andrew J. P. White, David J. Williams, Tomás TorrobaAbstract:Disulfur dichloride converts 1-(dicyanomethylene)indane 3 into the methyleneindene 4 and the red indeno-1,2-thiazine 5; it also converts inden-3-ylacetic acid 7 into methyleneindenes 8 and 9, dithiolone 10 and the deep purple thiophenone 11; upon melting crystals of 4 and 11 are strongly birefringent and 5 exhibits thermochromicity; mechanisms are outlined for the novel transformations and X-ray crystal structures for 5 and 10 are analysed.
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Cyclopenta-1,2-dithioles and cyclopenta-1,2-thiazines from new molecular rearrangements
Chemical Communications, 1996Co-Authors: Oleg A. Rakitin, Charles W. Rees, Tomás TorrobaAbstract:The cyclobutanone oxime 6 reacts with Disulfur dichloride to give two unexpected 10π pseudoazulenes in low yield: the dark blue cyclopenta-1,2-dithiole 7 and the orange cyclopenta-1,2-thiazine 8; the benzo derivative 14 of this oxime gives the analogous benzo product 15 together with the methylene indene 16 in high yield; mechanisms based on abnormal Beckman rearrangements are proposed for the formation of all of these products.