Impulsphotolytische Untersuchungen zum Mechanismus der photochemischen WoLFF-Umlagerung.

Bölsing, Friedrich; Spanuth, E.

doi:10.1515/znb-1976-1021

Cited by 5 publications

(1 citation statement)

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“…are broken up. [5][6] We report here a novel method for preparing an organic thin film by using this property of these surfactants, which demonstrates a new film-forming technique.…”

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confidence: 99%

Electrochemical formation of an organic thin film by disruption of micelles

Hoshino¹,

Saji²

1987

J. Am. Chem. Soc.

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“…are broken up. [5][6] We report here a novel method for preparing an organic thin film by using this property of these surfactants, which demonstrates a new film-forming technique.…”

mentioning

confidence: 99%

Electrochemical formation of an organic thin film by disruption of micelles

Hoshino¹,

Saji²

1987

J. Am. Chem. Soc.

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Wolff Rearrangement

2010

Comprehensive Organic Name Reactions and Reagents

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The thermal, photochemical or catalytic transformation of α‐diazoketones into ketenes is generally known as the Wolff rearrangement. The readiness of Wolff rearrangement is probably due to the evolution of a nitrogen molecule, forming a carbenic intermediate. Several transition metal catalysts have been used and it has been reported that the copper salt can facilitates the generation of a carbene intermediate and lower the energy barrier for the Wolff rearrangement, however, a silver salt is even better than the copper salt for such purpose. It has been reported that cyclic α‐diazoketones undergo the Wolff rearrangement to give the ring‐contracted cyclic carboxylic acids. The study finds that in the case of β‐oxy‐α‐diazoketones, such as β‐hydroxy‐α‐diazoketones, the regular alkyl migration in the normal Wolff rearrangement is depressed by the competitive 1,2‐H shift from hydroxyl to carbene, leading to 100% of vinyl ketones. In terms of the structures of α‐diazoketones, α‐diazo malonates often form vinyl alkyl ethers due to the loss of carbon monoxide. Furthermore, both carbon monoxide and oxygen are reported to suppress the Wolff rearrangement. It has also been reported that 2‐diazodibenzyl malonate undergoes the Wolff rearrangement more easily than 2‐diazodimethyl malonate in the presence of a transition metal catalyst. The reversal of the Wolff rearrangement, known as the retro ‐Wolff rearrangement, has also been reported. This reaction has very broad application in organic synthesis as well as in industrial imaging.

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Photoisomerisierung von 1‐(4‐Hydroxyphenyl)‐2‐methyldiazenen

Hofer

1979

Chem. Ber.

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Photochemisch induzierte Isomerisierungen der Titelverbindungen werden untersucht. Mit Hilfe von H-NMR-Spektroskopie wird gezeigt, daR die thermische cis-trans-Isomerisierung 3c + 3t iiber das tautomere Chinon-alkylhydrazon 3 H verlauft. Der Losungsmittel-und Substituenteneinfluo auf die Geschwindigkeit der thermischen cis-trans-Isomerisierung wird diskutiert. Die 'H-NMR-Daten fur die cis-Isomeren 2 c und 3 c werden angegeben. Photoisomerization of 1 -(4-Hydroxyphenyl)-2-methyldiazenesPhotochemically induced isomerizations of the title compounds have been studied. The thermal cis-trans isomerization 3 c -+ 3t occurs via the tautomeric quinone alkylhydrazone 3 H as shown by 'H NMR spectroscopy. The influence of solvent and substituents on the velocity of the thermal cis-trans isomerization is discussed. 'H NMR data for the cis-isomers 2 c and 3c are given.In einer ersten Mitteilung ') wurde die Synthese einiger trans-1-(4-Hydroxyphenyl)-2-methyldiazene 1 t beschrieben und iiber die Bestimmung von Tautomeren-und Stereoisomerengleichgewichten in Losung mit spektroskopischen Methoden (UV, IR, NMR) berichtet. Gegenstand der vorliegenden Untersuchungen sind Photoreaktionen der trans-Hydroxydiazene 1 t, wobei besonderes Augenmerk auf mogliche Photoisomerisierungen zu den cis-verbindungen 1 c und Phototautomerisierungen zu den Chinonalkylhydrazonen 1 H und den Aldehyd-hydrazonen 1A gerichtet werden sollte. Fur erste --3 ltBu tBu

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Impulsphotolytische Untersuchungen zum Mechanismus der photochemischen WoLFF-Umlagerung.

Cited by 5 publications

References 1 publication

Electrochemical formation of an organic thin film by disruption of micelles

Electrochemical formation of an organic thin film by disruption of micelles

Wolff Rearrangement

Photoisomerisierung von 1‐(4‐Hydroxyphenyl)‐2‐methyldiazenen

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