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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 335 (1993), S. 351-358 
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ring Transformations of Heterocyclic Compounds. I. 2-Amino-benzophenones and 7-Oxo-hepta-2,4-dienenitriles by Reaction of 2,4,6-Triarylpyrylium Salts with 4-Nitrobenzyl Cyanide2,4,6-Triarylpyrylium salts 1 react with 4-nitrobenzyl cyanide in the presence of sodium acetate, triethylamine or triethylamine/acetic acid to give 7-oxo-hepta-2,4-dienenitriles 2. With stronger bases such as sodium methanolate or ethanolate a ring transformation of the salts 1 occurs giving rise to 2-amino-benzophenones 3 which can also be obtained by cyclization of the nitriles 2. Under the same conditions the 3-methyl-2,4,6-triphenylpyrylium salt 4 forms the 4-methyl-7-oxo-hepta-2,4-dienenitrile 5 by regioselective addition of the 4-nitrobenzyl cyanide at C-2 or it is converted to the 2-amino-5-methyl-benzophenone 6. The ring transformation of the pyrylium salts 1/4 by 4-nitrobenzyl cyanide represents a new and simple method for the preparation of 2-amino-benzophenones. - Spectroscopic data of the novel compounds are discussed; the structure of 5 was confirmed by a single crystal X-ray analysis.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 337 (1995), S. 46-49 
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The hitherto unknown stereochemistry of N,N,N′,N′-tetrasubstituted 2-arylthioacrylamides 1 has been determined by X-ray crystal analysis and systematic NMR-investigations. Provided that the 2-aryl group lacks ortho substituents, compounds 1 exist predominantly as Z-isomers. In contrast, the major isomer has an E-s-trans configuration if the 2-aryl group is ortho-substituted. Substitution of the 3-amino group of 1 by glycinates, giving 3-aminothioacrylamides 2, generally preserves the original stereochemistry.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1693-1698 
    ISSN: 0044-2313
    Keywords: Tris(trimethylsilyl)methaneselenenyl halides ; Tris(trimethylsilyl)methaneselenyl chalcogenides ; 1H, 13C, 77Se n.m.r. sprectra ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tris(trimethylsilyl)methaneselenenyl Halides and Chalcogenides.Ditrisyldiselenide (1) (trisyl = TSi = (Me3Si)3C) reacts with SOCl2, Br2 and I2 to provide trisylselenenyl halides TSiSeX (2: X = Cl; 3: X = Br, 4: X = I). Insertion of S and Se into the Se—Se bond of 1 to yield (TSiSe)2Sn (5: n = 1; 6: n = 2) and (TSiSe)2Sen (7: n = 1; 8: n = 2) was catalysed by iodine. 5 was isolated in pure state and examined by X-ray diffraction. Triselenide 7 can be cleaved by I2 in CS2 to give 4 and Se2I2 (9). From 2 with Me3SiCN and Me3SiNCS, the new selenenyl pseudohalides TSiSeCN (10) and TSiSeSCN (11) were prepared. The compounds were characterised by 1H, 13C- and 77Se n.m.r. spectra.
    Notes: Ditrisyldiselenid (1) (Trisyl  -  Tsi  -  (Me3Si)3C—) reagiert mit SOCl2, Br2 und I2 zu Trisylselenenylhalogeniden TSiSeX (2: X = Cl; 3: X = Br, 4: X = I). Die Einschiebung von Schwefel und Selen in die Se—Se-Bindung von 1 zu (TSiSe)2 Sn (5: n = 1; 6: n = 2) bzw. (TSiSe)2Sen (7: n = 1; 8: n = 2) läßt sich mit Iod katalysieren. 5 wurde in reiner Form isoliert und durch Röntgenstrukturanalyse untersucht. Das Triselenid 7 wird durch Iod in CS2 zu 4 und Se2I2 (9) gespalten. Aus 2 lassen sich mit Me3SiCN bzw. Me3SiNCS das Trisylselenocyanat TSiSeCN (10) bzw. Trisylselenenylthiocyanat TSiSeSCN (11) gewinnen. 1H, 13C- und 77Se-NMR Spektren von 1 - 11 sind im Einklang mit den Strukturvorschlägen.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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