Library

Language
Preferred search index
Number of Hits per Page
Default Sort Criterion
Default Sort Ordering
Size of Search History
Default Email Address
Default Export Format
Default Export Encoding
Facet list arrangement
Maximum number of values per filter
Auto Completion
Feed Format
Maximum Number of Items per Feed
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Highly Reactive Trialkylsilylation Reagents Derived from Bis(trifluoromethanesulfonyl)imide - Silylation of Functional Groups, Alkines and Reactive AromaticsThe synthesis of trialylsilyl-bis(trifluormethane-sulfonyl)imides 3 is described. Compounds 3 with bulky trialkylsilyl groups 3a,b only exist in the silatautomeric form 3a′, b′ under usual conditions, 3c in the N-trimethylsilyl structure. Despite of the bulky silyl substituents in 3a′, b′ their reactivity is higher than of trimethylsilyltriflate. Alcohols, carbonyl compounds, nitroalkanes and carboxylic acid esters are silylated in good yields, especially by the more reactive triisopropylsilyl derivative 3b′ in presence of tertiary amines. tert.-Butyl carboxylates and benzylcarboxylates are cleaved. Monosubstituted alkines and electron-rich (hetero) aromatics are carbosilylated in presence of N-ethyl-diisopropylamine.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1978 (1978), S. 1937-1945 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Simple Synthesis of Tetraalkylammonium Salts with Functional AnionsTetraalkylammonium tetrafluoroborates react with potassium salts to give corresponding tetraalkylammonium salts 2 with functional anionic groups.  -  Methylation of tertiary amines with methyl chloroformate affords trialkyimethylammonium chlorides 3.
    Notes: Tetraalkylammoniumsalze 2 mit funktionellen anionischen Gruppen erhält man durch Umsetzung von Tetraalkylammonium-tetrafluoroboraten mit entsprechenden Kaliumsalzen.  -  Tertiäre Amine werden von Chlorameisensäure-methylester zu Trialkylmethylammoniumchloriden 3 methyliert.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 762 (1972), S. 62-72 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Orthoamides, XXIII1). - Reaction of Ortho Amide Derivatives with Compounds of the Type X-CH2-CH2-Y.Reaction of the bisdialkylaminoalkoxymethanes (aminal esters) 1a, b, d and trimorpholinomethane (amide aminal, 5) with compounds of the type X-CH2-CH2-Y (X and Y = electron attracting groups) gives the mono- and bis-dialkyiaminomethylene compounds 3 or 4 by abstraction of alcohol or dialkylaminomethane.
    Notes: Die Bis-dialkylamino-alkoxy-methane (Aminalester) 1a, b, d und Trimorpholino-methan (Amidaminal, 5) reagieren mit Verbindungen der Struktur X-CH2-CH2-Y, wobei X und Y elektronenanziehende Gruppen darstellen, unter Abspaltung von Alkohol und Dialkylamin zu den Mono- und Bis-dialkylaminomethylen-Verbindungen 3 bzw. 4.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1977 (1977), S. 1249-1266 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Reactions of 2-Chloro-1,3-thiazin-4-ones2-Chloro-1,3-thiazin-4-ones 2 and 4 are prepared by cyclization of 2-thiocyanatocarboxylic acid chlorides 1 and 3, respectively, with hydrogen chloride. The compounds 2 and 4 are cyclic, azavinylogous acid chlorides of ambivalent character and react with amines undergoing substitution of chlorine or fragmentation. The structure of the 2-amino-1,3-thiazin-4-ones 9 and 14 and the aromatic character of the 1,3-thiazin-4-ones 2 and of the 1,3-thiazinium salts 18 are investigated.
    Notes: 2-Chlor-1,3-thiazin-4-one 2 und 4 sind durch Cyclisierung von 2-Thiocyanatocarbonsäurechloriden 1 bzw. 3 mit Chlorwasserstoff zugänglich. Sie besitzen als cyclische, azavinyloge Säurechloride ambivalenten Charakter und reagieren mit Aminen unter Substitution des Chlors oder Fragmentierung. Die Struktur der 2-Amino-1,3-thiazin-4-one 9 und 14 sowie der aromatische Charakter der 1,3-Thiazin-4-one 2 und der 1,3-Thiaziniumsalze 18 werden untersucht.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses in the Heterocyclic Series, XIV1). Formylation of 4-Methylpyrimidine and Reactions of 2-[4-Pyrimidinyl]-malondialdehydeWith an excess of dimethylchloromethyleneiminium chloride 4-methylpyrimidine (1) gives 2-[4-pyrimidinyl]-malonic-dialdehyde (2), while with the stoichiometric quantity of the chloride and of hydrogen chloride N,N-dimethyl-2-[4-pyrimidinyl]-vinylamine (3) is formed. In the same way as the nitrosation this reaction is believed to proceed by a quasi p-quinoid intermediate. On reaction with hydrazines or formamide, 2 yields 4-[4-pyrazolyl]-pyrimidines (4, 5) or 4-[5-pyrimidinyl]-pyrimidine (6); on reaction with N-alkyl-substituted salts of benzothiazole or benzoselenazole γ-substituted pentacyanines (10a-c and 12) result.
    Notes: Die Formylierung von 4-Methyl-pyrimidin (1) mit überschüssigem Dimethylformamidchlorid (Dimethyl-chlormethylen-immoniumchlorid) zu 2-[Pyrimidinyl-(4)]-malondialdehyd (2) und mit äquimolaren Mengen Dimethylformamidchlorid/HCl zu N.N-Dimethyl-2-[pyrimidinyl-(4)]-vinylamin (3) erfolgt analog der Nitrosierung über ein quasi-p-chinoides Zwischenprodukt. 2 gibt mit Hydrazinen bzw. Formamid Ringschluß-Reaktionen zu 4-[Pyrazolyl-(4)]-pyrimidinen (4, 5) bzw. 4-[Pyrimidinyl-(5)]-pyrimidin (6); mit N-Alkyl-substituierten Benzthiazolium- oder Benzselenazolium-Salzen entstehen γ-substituierte Pentamethincyanin-Farbstoffe (10a-c und 12).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 737 (1970), S. 39-45 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses in the Heterocyclic Series, XIII1). Nitrosation of Acidic Alkyl Hydrogen in Heterocyclic CompoundsOn nitrosation with ethyl nitrite in the presence of an excess of hydrogen chloride, methylheterocycles afford hydrochloride salts of the aldoximes which may be liberated by treatment with aqueous potassium hydrogen carbonate. Formation of a quasi-p-quinoid intermediate is thought to be a necessary step in the course of the reaction.
    Notes: Die Nitrosierung von Methylheterocyclen mit Äthylnitrit in Gegenwart von überschüssiger Salzsäure führt zu den Aldoxim-hydrochloriden, die sich mit wäßriger Kaliumhydrogencarbonat-Lösung in die freien Aldoxime (Tab. 1, S. 44) überführen lassen. Für den Reaktionsablauf wird die Ausbildung eines quasi-p-chinoiden Zwischenproduktes gefordert.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses in the Heterocyclic Series, XVII1). Syntheses and Reactions of Pyrimidine-5-carbaldehydes.Formylation of the 6-oxo-4-hydroxydihydropyrimidines 1 with dimethylformamide chloride to N,N-dimethyl-N-(6-oxo-4-hydroxy-3,6-dihydro-5-pyrimidinyl)methyleneimonium chlorides 2 are described. 2 reacts with water to the 6-oxo-4-hydroxy-3,6-dihydropyrimidine-5-carbaldehydes 3, with phosphorous oxide chloride to the 4,6-dichloropyrimidine-5-carbaldehydes 4, with phenylhydrazine to the 6-oxo-4-hydroxy-5-phenylhydrazonomethylenedihydropyrimidines 5 and with malonic ester to the 5-hydroxy-3-ethoxycarbonylpyrimido[4,5-b]-α-pyrones 7. Catalytic dehalogenation of 4,6-dichlorpyrimidine-5-carbaldehyde (4a) yields pyrimidine-5-carbaldehyde (10), which is able to undergo most of the aldehyde reactions under mild conditions.
    Notes: Es wird die Formylierung der 6-Oxo-4-hydroxy-dihydropyrimidine 1 mit Dimethylformamid-chlorid zu N.N-Dimethyl-N-(6-oxo-4-hydroxy-3.6-dihydro-5-pyrimidinyl)-methyenimonium-chloriden 2 beschrieben, sowie die Umsetzung von 2 mit Wasser zu den 6-Oxo-4-hydroxy-3.6-dihydro-pyrimidin-5-carbaldehyden 3, mit Phosphoroxychlorid zu den 4.6-Dichlor-pyrimidin-5-carbaldehyden 4, mit Phenylhydrazin zu den 6-Oxo-4-hydroxy-5-phenylhydrazonomethylen-dihydropyrimidinen 5 und mit Malonester zu den 5-Hydroxy-3-äthoxycarbonyl-pyrimido[4.5-b]-α-pyronen 7. Die katalytische Dehalogenierung von 4.6-Dichlor-pyrimidin-5-carbaldehyd (4a) führt zum Pyrimidin-5-carbaldehyd (10), der unter milden Bedingungen den meisten Aldehyd-Reaktionen zugänglich ist.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1802-1815 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Structure of 3-Isoquinolinols**)1-Halogeno-3-isoquinolinols 2-4 are prepared by cyclization of (2-cyanophenyl)acetyl chlorides 1 in presence of anhydrous hydrogen halides. Catalytic hydrogenation gives the 3-isoquinolinols 8. The lactam-lactim tautomerism of these compounds is discussed.
    Notes: (2-Cyanphenyl)acetylchloride 1 cyclisieren in Gegenwart wasserfreier Halogenwasserstoffsäuren zu I-Halogen-3-isochinolinolen 2-4. Durch katalytische Hydrierung erhält man aus diesen die 3-Isochinolinole 8. Die Lactam-Lactim-Tautomerie dieser Verbindungsklassen wird untersucht.
    Additional Material: 10 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1978 (1978), S. 1946-1962 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Nitriles with Tetraalkylammonium CyanidesPrimary and secondary alkyl halides, 2-halo carboxylic esters, as well as acyl halides react with tetraalkylammonium cyanides 1a, 1b in polar aprotic and nonpolar solvents to give the nitriles 2-8. 2-Halo ketones form oxiranecarbonitriles 9 under mild conditions. Under more vigorous conditions, especially in presence of tetraethylammonium bromide, 3-oxonitriles 11 are the reaction products. The reactivity of the salts 1a and 1b in different solvents is investigated.
    Notes: Primäre und sekundäre Halogenalkane, 2-Halogencarbonsäureester und Acylhalogenide setzen sich in polar-aprotischen und unpolaren Solventien mit den Tetraalkylammoniumcyaniden 1a und 1b zu den Nitrilen 2-8 um. 2-Halogenketone bilden unter milden Bedingungen 2-Oxirancarbonitrile 9, unter verschärften Reaktionsbedingungen, besonders in Gegenwart von Tetraethylammoniumbromid die 3-Oxonitrile 11.  -  Die Reaktivität der Salze 1a und 1b in verschiedenen Lösungsmitteln wurde untersucht.
    Additional Material: 12 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1643-1657 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Trialkylsilyl Trifluoromethanesulfonates, I. - Synthesis of Trialkylsilyl Enol EthersThe reactions of the ketones 2, 2-bromoketones 6, α,β-unsaturated ketones 8, 1,2-diketones, and aliphatic aldehydes 20 with trialkylsilyl triflates 1 in the presence of triethylamine (4) at room temperature yield the silyl enol ethers 3, 7, 9, 11, and 21. The silylation of the unsymmetrical ketones 12 with 1a/4 runs regioselectively in the thermodynamical sense using 1a/12 in excess and yields the enol ethers 13t. The course of this reaction is discussed briefly.
    Notes: Die Ketone 2, 2-Bromketone 6, α,β-ungesättigte Ketone 8, 1,2-Diketone 10 und aliphatische Aldehyde 20 setzen sich mit Trialkyisilyl-triflaten 1 in Gegenwart von Triethylamin (4) bei Raum-temperatur zu den Silylenolethern 3, 7, 9, 11 und 21 um. Die Silylierung unsymmetrischer Ketone 12 mit 1a/4 verläuft mit überschüssigem 1a und 12 regioselektiv im thermodynamischen Sinn zu den Enolethern 13t. Der Reaktionsablauf wird kurz diskutiert.
    Additional Material: 9 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...