The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Pál Sohár - One of the best experts on this subject based on the ideXlab platform.
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A useful ring transformation route to novel thiazepino[7,6-b]indoles from monochloro-β-lactam-fused 1,3-thiazino[6,5-b]indoles, analogues of cyclobrassinin
Tetrahedron, 2017Co-Authors: Peter Csomos, Lajos Fodor, Antal Csámpai, Pál SohárAbstract:Abstract The Staudinger ketene-imine cycloaddition reactions of cyclobrassinin phytoalexin analogues 2-aryl-4,9-dihydro-1,3-thiazino[6,5-b]indoles with chloroacetyl chloride as a ketene source were investigated under different conditions. Both β-lactam ring formation and the N-chloroacetylation of the indole moiety took place. The indole N-chloroacetyl group can be easily removed by treatment in the presence of silica gel in methanol at reflux temperature. The selective β-lactam formation can be also achieved in certain cases under milder Staudinger conditions. The treatment of azeto[2,1-b]thiazino[6,5-b]indole-1-one derivatives with sodium ethoxide in ethanol provided the novel thiazepino[7,6-b]indole ring systems in a one-step ring transformation. The structures of the new ring systems were determined by means of IR and NMR spectroscopy.
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novel indole syntheses by ring transformation of β lactam condensed 1 3 benzothiazines into indolo 2 3 b 1 4 benzothiazepines and indolo 3 2 c isoquinolines
Tetrahedron, 2012Co-Authors: Peter Csomos, Antal Csámpai, L Fodor, Pál SohárAbstract:Abstract ortho-Nitrophenyl-substituted condensed 1,3-benzothiazines proved to be a useful core unit in indole syntheses under non-reductive conditions. Thus, the treatment of ortho-nitro-2-aryl-2a-chloro-4H-azeto[2,1-b][1,3]benzothiazin-1-ones with sodium methoxide in methanol provided indolo-1,4-benzothiazepines via a novel rearrangement. Through the sulfur extrusion reaction of indolo[2,3-b][1,4]benzothiazepines, further alkaloid-type indole derivatives, indolo[3,2-c]isoquinolines, were obtained. The structures of the new ring systems were determined by means of NMR spectroscopy.
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A Convenient Synthesis of 1,4-Benzothiazepinesfrom 1,3-Benzothiazines via the Ring Transformation of β-Lactam-Condensed1,3-Benzothiazine Derivatives
Synthesis, 2010Co-Authors: Lajos Fodor, Peter Csomos, Antal Csámpai, Pál SohárAbstract:A convenient synthesis was devised for rare 2,3-disubstituted 4,5-dihydro-1,4-benzothiazepines from 2-aryl-4H-1,3-benzothiazines. The Staudinger reaction of 1,3-benzothiazines obtained with chloroacetyl chloride selectively furnished trans-monochloroβ-lactam-condensed thiazines. The ring expansion of azeto[2,1-b][1,3]benzothiazin-1-one derivatives with sodium methoxide afforded 1,4-benzothiazepines as the sole product in good yields. The structures of the new molecules were proved by means NMR and IR spectroscopy.
Koichi Komatsu - One of the best experts on this subject based on the ideXlab platform.
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the reaction of fullerene c 60 with 4 6 dimethyl 1 2 3 triazine formation of an open cage fullerene derivative
Journal of Organic Chemistry, 2001Co-Authors: Yasujiro Murata, Michihisa Murata, Koichi KomatsuAbstract:A thermal reaction of fullerene C60 with 4,6-dimethyl-1,2,3-triazine (4) in o-dichlorobenzene gave azacyclohexadiene-fused fullerene derivative 5, by the reaction with intermediate Azete 11, and then, after flash chromatography over SiO2, open-cage fullerene derivative 6 having an eight-membered ring orifice on the C60 cage. Compound 6 is assumed to be formed via addition of diradical intermediate 13 to C60. Compound 6 underwent a further photochemical reaction with singlet oxygen with the cleavage of one of the double bonds at the rim of the orifice to afford triketone derivative 8 having a 12-membered ring orifice.
Yasujiro Murata - One of the best experts on this subject based on the ideXlab platform.
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the reaction of fullerene c 60 with 4 6 dimethyl 1 2 3 triazine formation of an open cage fullerene derivative
Journal of Organic Chemistry, 2001Co-Authors: Yasujiro Murata, Michihisa Murata, Koichi KomatsuAbstract:A thermal reaction of fullerene C60 with 4,6-dimethyl-1,2,3-triazine (4) in o-dichlorobenzene gave azacyclohexadiene-fused fullerene derivative 5, by the reaction with intermediate Azete 11, and then, after flash chromatography over SiO2, open-cage fullerene derivative 6 having an eight-membered ring orifice on the C60 cage. Compound 6 is assumed to be formed via addition of diradical intermediate 13 to C60. Compound 6 underwent a further photochemical reaction with singlet oxygen with the cleavage of one of the double bonds at the rim of the orifice to afford triketone derivative 8 having a 12-membered ring orifice.
Peter Csomos - One of the best experts on this subject based on the ideXlab platform.
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A useful ring transformation route to novel thiazepino[7,6-b]indoles from monochloro-β-lactam-fused 1,3-thiazino[6,5-b]indoles, analogues of cyclobrassinin
Tetrahedron, 2017Co-Authors: Peter Csomos, Lajos Fodor, Antal Csámpai, Pál SohárAbstract:Abstract The Staudinger ketene-imine cycloaddition reactions of cyclobrassinin phytoalexin analogues 2-aryl-4,9-dihydro-1,3-thiazino[6,5-b]indoles with chloroacetyl chloride as a ketene source were investigated under different conditions. Both β-lactam ring formation and the N-chloroacetylation of the indole moiety took place. The indole N-chloroacetyl group can be easily removed by treatment in the presence of silica gel in methanol at reflux temperature. The selective β-lactam formation can be also achieved in certain cases under milder Staudinger conditions. The treatment of azeto[2,1-b]thiazino[6,5-b]indole-1-one derivatives with sodium ethoxide in ethanol provided the novel thiazepino[7,6-b]indole ring systems in a one-step ring transformation. The structures of the new ring systems were determined by means of IR and NMR spectroscopy.
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novel indole syntheses by ring transformation of β lactam condensed 1 3 benzothiazines into indolo 2 3 b 1 4 benzothiazepines and indolo 3 2 c isoquinolines
Tetrahedron, 2012Co-Authors: Peter Csomos, Antal Csámpai, L Fodor, Pál SohárAbstract:Abstract ortho-Nitrophenyl-substituted condensed 1,3-benzothiazines proved to be a useful core unit in indole syntheses under non-reductive conditions. Thus, the treatment of ortho-nitro-2-aryl-2a-chloro-4H-azeto[2,1-b][1,3]benzothiazin-1-ones with sodium methoxide in methanol provided indolo-1,4-benzothiazepines via a novel rearrangement. Through the sulfur extrusion reaction of indolo[2,3-b][1,4]benzothiazepines, further alkaloid-type indole derivatives, indolo[3,2-c]isoquinolines, were obtained. The structures of the new ring systems were determined by means of NMR spectroscopy.
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A Convenient Synthesis of 1,4-Benzothiazepinesfrom 1,3-Benzothiazines via the Ring Transformation of β-Lactam-Condensed1,3-Benzothiazine Derivatives
Synthesis, 2010Co-Authors: Lajos Fodor, Peter Csomos, Antal Csámpai, Pál SohárAbstract:A convenient synthesis was devised for rare 2,3-disubstituted 4,5-dihydro-1,4-benzothiazepines from 2-aryl-4H-1,3-benzothiazines. The Staudinger reaction of 1,3-benzothiazines obtained with chloroacetyl chloride selectively furnished trans-monochloroβ-lactam-condensed thiazines. The ring expansion of azeto[2,1-b][1,3]benzothiazin-1-one derivatives with sodium methoxide afforded 1,4-benzothiazepines as the sole product in good yields. The structures of the new molecules were proved by means NMR and IR spectroscopy.
Lajos Fodor - One of the best experts on this subject based on the ideXlab platform.
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A useful ring transformation route to novel thiazepino[7,6-b]indoles from monochloro-β-lactam-fused 1,3-thiazino[6,5-b]indoles, analogues of cyclobrassinin
Tetrahedron, 2017Co-Authors: Peter Csomos, Lajos Fodor, Antal Csámpai, Pál SohárAbstract:Abstract The Staudinger ketene-imine cycloaddition reactions of cyclobrassinin phytoalexin analogues 2-aryl-4,9-dihydro-1,3-thiazino[6,5-b]indoles with chloroacetyl chloride as a ketene source were investigated under different conditions. Both β-lactam ring formation and the N-chloroacetylation of the indole moiety took place. The indole N-chloroacetyl group can be easily removed by treatment in the presence of silica gel in methanol at reflux temperature. The selective β-lactam formation can be also achieved in certain cases under milder Staudinger conditions. The treatment of azeto[2,1-b]thiazino[6,5-b]indole-1-one derivatives with sodium ethoxide in ethanol provided the novel thiazepino[7,6-b]indole ring systems in a one-step ring transformation. The structures of the new ring systems were determined by means of IR and NMR spectroscopy.
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A Convenient Synthesis of 1,4-Benzothiazepinesfrom 1,3-Benzothiazines via the Ring Transformation of β-Lactam-Condensed1,3-Benzothiazine Derivatives
Synthesis, 2010Co-Authors: Lajos Fodor, Peter Csomos, Antal Csámpai, Pál SohárAbstract:A convenient synthesis was devised for rare 2,3-disubstituted 4,5-dihydro-1,4-benzothiazepines from 2-aryl-4H-1,3-benzothiazines. The Staudinger reaction of 1,3-benzothiazines obtained with chloroacetyl chloride selectively furnished trans-monochloroβ-lactam-condensed thiazines. The ring expansion of azeto[2,1-b][1,3]benzothiazin-1-one derivatives with sodium methoxide afforded 1,4-benzothiazepines as the sole product in good yields. The structures of the new molecules were proved by means NMR and IR spectroscopy.
