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  • 1
    Electronic Resource
    Electronic Resource
    Organic photochemistry. XXXVIII. Photochemistry without light and the stereochemistry of the type A dienone rearrangement (1969)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 91 (1969), S. 434-445 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja01030a039
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  • 2
    Electronic Resource
    Electronic Resource
    Reactions of 2-(Organylseleno)propenenitriles with Dimethyl EthynedicarboxylateDedicated to Professor Peter Sartori on the occasion of his 65th birthday.Parts of this work were taken from the doctoral dissertation of Thomas Sturm, Gerhard-Mercator University Duisburg, 1996. (1997)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1997 (1997), S. 541-546 
    Details
    ISSN: 0947-3440
    Keywords: [3 + 2] Cycloadditions ; Organylseleno group transfer ; 2,3-Dihydroselenophenes ; Polysubstituted butadienes ; Selenium ; Alkenes ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (2-tert-Butylseleno)propenenitrile (12a) has been prepared and treated with dimethyl ethynedicarboxylate (3) and methyl propiolate (18) to give the 2,3-dihydroselenophenes 16 and 21, respectively. In contrast, 2-(ethylseleno)-, 2-(methylseleno)- and 2-(phenylseleno)propenenitrile (12b-d) tend to form polysubstituted butadienes 17b-d with 3 by net organoylseleno group transfer from 12b-d to C-2 of 3 following attachment of C-3 of 17 to C-3 of 3. Five-membered selenonium ylides are proposed as intermediates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199719970315
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  • 3
    Electronic Resource
    Electronic Resource
    Photoaddition of 2-Morpholinoacrylonitrile to Substituted 1-Acetonaphthones (1997)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1997 (1997), S. 1023-1027 
    Details
    ISSN: 0947-3440
    Keywords: Cycloadditions ; Exciplex or diradical intermediate ; 1,4-Ethanonaphthalenes ; Cyclobuta[a]naphthalenes ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Substituted 1-acetonaphthones 6b-d and 2-morpholinoacrylonitrile (2a) undergo a photocycloaddition. The type of addition ([2 + 2] vs. [4 + 2]) is dependent on the location of additional substituents. Whereas compound 6c with a methoxy group at C-2 gave only the [4 + 2]-cycloadduct 11, the formation of [2 + 2]-cycloadducts was observed with 6b, d with cyano and methoxy groups, respectively, at C-4. In the case of the 4-bromo derivative 6a, photosubstitution was observed. The endo or exo orientation of the morpholino group in the cycloadducts was determined by an X-ray crystal structure analysis for 9b, as well as by NOE signal intensity difference determination experiments for 9a and 11.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199719970535
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  • 4
    Electronic Resource
    Electronic Resource
    Notiz zur Hydroborierung von Bicyclo[3.1.0]hexen-(2)-carbonsäure-(6endo)-methylester (1969)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 102 (1969), S. 1081-1083 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19691020345
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  • 5
    Electronic Resource
    Electronic Resource
    Indoleninoxide, III. Photoisomerisierung und Acidolyse von 3,3-Dimethyl-3H-indol-1-oxiden (1976)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 109 (1976), S. 3849-3863 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Indolenine Oxides, III Photoisomerization and Acidolysis of 3,3-Dimethyl-3H-indole 1-OxidesIrradiation of the 3H-indole 1-oxides 2a,b in cyclohexane results in the formation of the very unstable 7,7a-dihydrooxazirino[a]indoles 8a,b which are transformed into the oxindoles 4a,b by a 1,2-hydrogen shift or into the 4H-3,1-benzoxazines 15a,b by ring opening between carbon atoms 2 and 3 and electrocyclic ring closure, respectively. When methanol is used as solvent for the irradiation of 2b, the main product is 2,4-di-tert-butyl-6-isopropylphenyl isocyanate (14). The course of the reaction is heavily influenced by both steric factors and solvent and is rationalized in part on the basis of a generally accepted mechanism of nitrone photolysis. Acidic methanolysis of 2a,b generates the oxindoles 4a, b as minor and the 5-Methoxy-3H-indoles 26a,b as major products. In contrast, hydrolysis of 2a with 25 p. ct. aqueous sulfuric acid affords mainly products of ring opening between C-2 and C-3.
    Notes: Bei Belichtung der 3H-Indol-1-oxide 2a,b in Cyclohexan werden die sehr instabilen 7,7a-Dihydro-oxazirino[a]indole 8a,b gebildet, die unter Wasserstoffwanderung in die Oxindole 4a,b bzw. unter Öffnung der Bindung zwischen C-2 und C-3 in die 4H-3,1-Benzoxazine 15a,b übergehen. Wird 2b in Methanol belichtet, ist 2,4-Di-tert-butyl-6-isopropylphenylisocyanat (14) Hauptprodukt. Der Reaktionsablauf, der stark von sterischen Einflüssen und vom Lösungsmittel abhängt, wird teilweise auf der Basis allgemein akzeptierter Vorstellungen über den Verlauf der Photolyse von Nitronen erklärt. Die saure Methanolyse von 2a,b liefert neben den Oxindolen 4a,b die 5-Methoxy-3H-indole 26a, b als Hauptprodukte, bei der Hydrolyse von 2a in 25 proz. wäßriger Schwefelsäure werden dagegen Produkte der Ringöffnung zwischen C-2 und C-3 erhalten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19761091213
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  • 6
    Electronic Resource
    Electronic Resource
    Photochemie aromatischer Nitroverbindungen, II. Lichtinduzierter intramolekularer Ringschluß von o-Nitro-tert.-butylbenzol (1971)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 104 (1971), S. 1035-1042 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemistry of Aromatic Nitro Compounds, II. Photoinduced Intramolecular Ring Closure of o-Nitro-tert-butylbenzenePhotolysis of o-nitro-tert-butylbenzene (1) in methanol containing sodium hydroxide leads to formation of small amounts of hydroxyazocompound 2 and to a 66 % yield of 1-hydroxy-3.3-dimethyl-2(3H)-indolone (3a), the structure of which is confirmed spectroscopically and by reduction to the known 3.3-dimethyl-2(3H)-indolone (6). The mass spectrum of 3a is discussed.
    Notes: Die Photolyse von 2-Nitro-1-tert.-butyl-benzol (1) in methanolischer-Natronlauge liefert neben geringen Mengen der Hydroxyazoverbindung 2 in 66 proz. Ausbeute 1-Hydroxy-3.3-dimethyl-3H-indolon-(2) (3a), dessen Struktur spektroskopisch sowie durch Reduktion zum bekannten 3.3-Dimethyl-3H-indolon-(2) (6) gesichert wird. Das Massenspektrum von 3a wird diskutiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19711040410
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  • 7
    Electronic Resource
    Electronic Resource
    Photochemie aromatischer Nitroverbindungen, III. Über den Mechanismus der lichtinduzierten Bildung von 1-Hydroxy-3.3-dimethyl-3H-indolonen-(2) aus o-Nitro-tert.-butylbenzolen (1971)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 104 (1971), S. 1043-1057 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemistry of Aromatic Nitro Compounds, III. On the Mechanism of Light-Induced Formation of 1-Hydroxy-3.3-dimethyl-2(3H)-indolones from o-Nitro-tert-butylbenzenesIrradiation of o-nitro-tert-butylbenzenes 1a-e followed by alkaline and oxidative workup affords 1-hydroxy-3.3-dimethyl-2(3H)-indolones 2a-e, whereas 4-amino-2-nitro-tert-butylbenzene (1f) is photostable. The photolysis of model compound 1b in several solvents is investigated. Spectroscopic data and the sensitisation by benzophenone suggest that the lowest triplet of 1b with n-π*-character is the reactive species. The quantum yield for the formation of product 2b from 1b is (1.2 ± 0.1) × 10-2 mmoles/mEinstein. A reaction mechanism accounting for all products found is suggested.
    Notes: Die Photolyse der o-Nitro-tert.-butylbenzole 1a-e liefert bei alkalisch-oxydativer Aufarbeitung die 1-Hydroxy-3.3-dimethyl-3H-indolone-(2) 2a-e, während 2-Nitro-4-amino-tert.-butylbenzol (1f) photostabil ist. Die Modellsubstanz 1b wird in verschiedenen Lösungs-mitteln belichtet. Spektroskopische Befunde und die Sensibilisierung durch Benzophenon legen nahe, daß der unterste angeregte Triplettzustand von 1b mit n-π*-Charakter für die Reaktion verantwortlich ist. Die Quantenausbeute für die Bildung des Produktes 2b aus 1b beträgt (1.2 ± 0.1) × 10-2m Mol/mEinstein. Ein Reaktionsmechanismus, der alle gefundenen Produkte berücksichtigt, wird vorgeschlagen.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19711040411
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  • 8
    Electronic Resource
    Electronic Resource
    Photochemie aromatischer Nitroverbindungen, IX. Photolyseprodukte des 1,3,5-Tri-tert-butyl-2-nitrobenzols (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 301-313 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemistry of Aromatic Nitro Compounds, IX. Products from Photolysis of 1,2,5-Tri-tertbutyl-2-nitrobenzenUpon irradiation in acetic acid, methanol, acetone, dioxane, benzene, and cyclohexane solution or as powdered crystals 1,3,5-tri-tert-butyl-2-nitrobenzene (1) is converted to 5,7-di-tert-butyl-3,3-dimethyl-3H-indole-1-oxide (5), which may be isolated. Alternatively, depending on the reaction conditions, 5 may be photoisomerized to various products or oxidized to 5,7-di-tert-butyl-1-hydroxy-3,3-dimethyl-2-indolinone (4a). In di- or triethylamine solution, smooth photoreduction of the nitro group of 1 without interference by the ortho tert-butyl groups is observed; all products isolated are derived from 1,3,5-tri-tert-butyl-2-(hydroxylamino)benzene.
    Notes: Bei der Bestrahlung in Eisessig, Methanol, Aceton, Dioxan, Benzol und Cyclohexan sowie als kristallines Pulver geht 1,3,5-Tri-tert-butyl-2-nitrobenzol (1) in 5,7-Di-tert-butyl-3,3-dimethyl-3H-indol-1-oxid (5) über, welches je nach den Reaktionsbedingungen als solches isoliert werden kann oder zu verschiedenen Produkten photoisomerisiert bzw. zu 5,7-Di-tert-butyl-1-hydroxy-3,3-dimethyl-2-indolinon (4a) oxidiert wird. In Di- bzw. Triäthylamin findet glatte Photoreduktion der Nitrogruppe ohne Beteiligung der ortho-tert-Butylgruppen statt, man isoliert Produkte, die sich sämtlich vom 1,3,5-Tri-tert-butyl-2-(hydroxylamino)benzol ableiten.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080138
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  • 9
    Electronic Resource
    Electronic Resource
    Bildungsweisen und Charakterisierung von 4-Oxatricyclo[3.3.0.02,8]oct-6-en-3-on (1982)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 346-354 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Methods of Formation and Characterization of 4-Oxatricyclo[3.3.0.02,8]oct-6-en-3-oneAlternatively to a published procedure, the title compound 4 - being of general interest both as formal 1,3-photo-adduct of carbon dioxide to benzene and as building block in prostaglandin synthesis - is prepared conveniently by dehydrobromination of the tricyclic bromolactone 12. It is also accessible by sensitized photooxidation of bicyclo[3.1.0]hex-2-ene-endo-6-carboxylic acid (5a).
    Notes: Alternative zu einer publizierten Vorschrift kann die Titelverbindung 4 - die als formales 1,3-Photoaddukt von Kohlendioxid an Benzol und als Prostaglandin-Baustein von allgemeinem Interesse ist - bequem durch Dehydrobromierung des tricyclischen Bromlactons 12 dargestellt werden. Sie ist ebenfalls durch sensibilisierte Photooxidation von Bicyclo[3.1.0]hex-2-en-endo-6-carbonsäure (5a) zugänglich.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19821150131
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  • 10
    Electronic Resource
    Electronic Resource
    Cycloaddition von α-(tert-Butylthio)acrylonitril an C, N-Diphenylnitron (1982)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 798-800 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cycloaddition of α-(tert-Butylthio)acrylonitrile to C,N-DiphenylnitroneThe radicophilic olefin 1a undergoes a smooth 1,3-dipolar cycloaddition to C,N-diphenylnitrone (4) with formation of 5,5-disubstituted isoxazolidines 5A, B as the major products accompanied by minor amounts of the regioisomeric adducts 6 and 7. No products other than 1: 1 cycloadducts have been detected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19821150242
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