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  • 1
    ISSN: 0947-3440
    Keywords: Sulfenes ; [4 + 2] Cycloaddition ; Cyclopentadiene ; (+)-10-Camphorsulfonyl chloride ; Sulfonyl cyclopentadienides ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The bulky sulfenes generated in situ from (+)-10-camphor-, 10-camphane-, and 2-methyl-2-phenylpropanesulfonyl chloride (1a-c) and Et3N can be trapped by cyclopentadiene to give the [4 + 2] cycloadducts 6a-c. The mixture of endo-6a and exo-6a (no other diastereomers) is formed by complete asymmetric induction. In MeCN solution additionally the 1,3-di- and 1,2,4-trisulfonylated cyclopentadienides 4a-c and 5a (X-ray analysis) + 5c were obtained. On acidification, 4a and 5a were transformed into the pentafulvenoid derivatives 8a, 9a, 10a. The reaction of (+)-10-camphorsulfonyl chloride (1a)/Et3N with 1,2,3,4-tetraphenylcyclopentadiene afforded the sulfonylated product 11a, with 2-methylcyclopentadiene 50% endo-12a (X-ray analysis) and 10% exo-12a. From cyclopentadiene and the more electrophilic cyanosulfene (2e) and mesylsulfene (2f, X = Me), generated in situ from cyanomethanesulfonyl chloride (1e)/Et3N and from mesyl chloride/Et3N, the [4 + 2] cycloadducts 6e and 6g were obtained. Similarly, methanedisulfonyl dichloride (1f, X = Cl)/Et3N afforded stereospecifically by two subsequent [4 + 2] cycloadditions the spirodisulfone 16 (X-ray analysis).
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0947-3440
    Keywords: 1,2,3,4,5-Pentamethylcyclopentadiene ; 1,3-Diphenylbenzo[c]furan ; Sulfenes ; [4 + 2] Cycloaddition ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Sulfenes 2a-o, generated in situ from sulfonyl chlorides and Et3N, are trapped by 1,2,3,4,5-pentamethylcyclopentadiene (6) to give [4 + 2] cycloadducts 8a-o containing the 7-methyl group in anti position. With mesylsulfene (7), formed in situ from mesyl chloride/Et3N in MeCN solution, the [4 + 2] cycloaddition to endo/exo- 9 (X-ray analyses) is accompanied by a [2 + 2] cycloaddition to 10 (X-ray analysis). (+)-10-Camphorsulfonyl chloride/Et3N afforded only two (and no more) diastereomeric [4 + 2] cycloadducts (endo/exo-8d). Et3N can be replaced by Me3N, N,N,N′,N′-tetramethylnaphthalene- 1,8-diamine or NaH, the sulfonyl chlorides to a limited extent by sulfonyl fluorides, sulfonic acid anhydrides or aryl esters. Formation of 8p from 6 and dichloromethanesulfonyl chloride requires NaH or AgNO3 or tertiary amine/AgNO3. N-(2-Methyl-1-propenyl)pyrrolidine is more reactive than 6 in trapping sulfene 2a. 6, however, is a more efficient sulfene scavenger than 1,3-diphenylbenzo[c]furan (19), which reacts with sulfene 2d by [4 + 2] cycloaddition and SO2 extrusion to give ketone 21d in only 18% yield.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1979 (1979), S. 617-627 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enamines, XVII. Addition of aromatic Acyl Chlorides to β-disubstituted EnaminesAromatic acyl chlorides react with β-disubstituted enamines at different rates to give (2-aroylalkyliden)ammonium chlorides 2. Acid hydrolysis of 2 yields 2-aroylaldehydes 3, while basic hydrolysis gives alkyl aryl ketones 6. On reaction with triethylammonium azide and Cyclohexyl isocyanide 2c loses the aroyl group to form 8.
    Notes: Aromatische Carbonsäurechloride setzen sich unterschiedlich rasch mit β-verzweigten Enaminen zu (2-Aroylalkyliden)ammoniumchloriden 2 um. Saure Hydrolyse von 2 führt zu den 2-Aroyl-aldehyden 3, alkalische zu den Alkylarylketonen 6. Mit Triethylammoniumazid und Cyclohexylisocyanid reagiert 2c unter Verlust des Aroylrestes zu 8.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0009-2940
    Keywords: Episulfones ; Thiirane 1,1-dioxides ; Alkenes ; Sulfines ; Sulfonylsulfene-amine S,N-adducts ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Secondary Reactions of Sulfenes from Sulfonyl Chlorides and Tertiary Amines, 2.  -  Formation of Episulfones, Sulfonylsulfene  -  Amine S.N-Adducts. and Chlorosulfines from Primary Sulfonyl Chlorides and Tertiary AminesThe reaction of primary sulfonyl chlorides 1b-m with the tertiary amine bases quinuclidine, DABCO, Me3N, Et3N, Bu3N, EtiPr2N, and 1,2,2,6,6-pentamethylpiperidine is studied in acetonitrile solution between - 40 and 80°C. The 2,3-dialkylthiirane 1,1-dioxides 4 (trans/cis 〉 1) and the alkenes 5 [(E)/(Z) 〉 1] are obtained in high yields with Et3N at - 40°C. The stereochemistry is influenced by the amine base B in the ring closure reaction and partially by epimerization of the episulfones 4. Hindered bases favor the cis, β-branched sulfonyl chlorides the trans isomer. Competing formation of the sulfonylsulfene-amine S,N-adducts 7 is only observed with quinuclidine, DABCO, and Me3N, which are also the most active amines in the epimerization of the cis-2,3-diarylthiirane 1,1-dioxides 4. Methanesulfonyl chloride (1a) yields the mesylsulfene-amine S,N-adducts 7a with Me3N and Et3N in MeCN, but thiirane 1,1-dioxide (4a) with EtiPr2N in MeCN or with Et3N in Et2O. Formation of chlorosulfines 10 is favored by higher temperature (T 〉 20°C), hindered amine bases and β-branched sulfonyl chlorides. Isolation of 10g and 10h in high yields shows that tert-alkylchlorosulfines are rather stable sulfines.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 1563-1570 
    ISSN: 0009-2940
    Keywords: Sulfene-amine adducts ; Amine-sulfene adducts ; 2-Trimethylammonio-2-propanesulfinate ; Episulfones ; Sulfones, α-chloro- ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Secondary Reactions of Sulfenes from Sulfonyl Chlorides and Tertiary Amines, 1. - On the Competing Formation of Sulfene - Trialkylamine S,N- and C,N-AdductsPhenylmethanesulfonyl chloride (1a) reacts with an excess of triethylamine in acetonitrile solution at -40°C to give stilbene episulfone (9a, 95%) via the phenylsulfene-triethylamine S,N-adduct 1ah. With trimethylamine and quinuclidine the yield of stilbene is reduced by the additional formation of (benzylsulfonyl)phenylsulfene-amines S,N-adducts 11ag and 11ae and C,N-adducts 15ag and 15ae which was proven by reaction with dimethylamine to 16 and by hydrolysis to 17-19, respectively. 1d reacts with triethylamine yielding 94% of α-chloro sulfones 4s and 6d via pentamethylenesulfene-triethylamine S,N-adduct 5dh, with trimethylamine, however, C,N-adduct 12dg is obtained which is easily oxidized to 20dg (47%). The air-sensitive dimethylsulfene-trimethylamine C,N-adduct 12cg was isolated and characterized.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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