Synthesis and photocyclization of some 4‐(5)arylethenylimidazoles

Lindgren, Gerd; Stensiö, Karl-Erland; Wahlberg, Kerstin

doi:10.1002/jhet.5570170411

Cited by 8 publications

(2 citation statements)

References 17 publications

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“…The only other report in the literature we are aware of is by Gewitz et al (37), who reacted free L-histidine with L-amino acid oxidase and horseradish peroxidase to yield 4(5)-imidazolecarboxaldehyde, 4(5)-imidazolecarboxylic acid, carbon dioxide, ammonia, and hydrogen peroxide. 4(5)-imidazolecarboxaldehyde is commercially available and can be prepared through a variety of synthetic pathways (37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49), which are different from the oxidation of L-histidine currently being discussed. Fig.…”

Section: Discussionmentioning

confidence: 99%

Oxidation of Free L-histidine by tert-Butylhydroperoxide

et al. 2010

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Section: Discussionmentioning

confidence: 99%

Oxidation of Free L-histidine by tert-Butylhydroperoxide

et al. 2010

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“…Similar cyclization can proceed for o-halostilbene 169) and styryl hetero rings. 80,170) Diniconazole 78) and uniconazole 171) were rapidly isomerized by irradiation to their Z-isomers which underwent this type of cyclization very efficiently between the phenyl C 2 and triazolyl C 5 . The C-C(Cl) bond formation between two aromatic rings connected by various linkages has been reported in the aqueous photolysis of pesticides.…”

Section: Intramolecular Bond Formation-cyclization 321 C-c Bond Fomentioning

confidence: 99%

Direct photolysis mechanism of pesticides in water

Katagi

2018

Journal of Pesticide Science

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Photodegradation is one of the most important abiotic transformations for pesticides in the aquatic environment, and the high energy of sunlight causes characteristic reactions such as bond scission, cyclization, and rearrangement, which are scarcely observed in hydrolysis and microbial degradation. This review deals with direct photolysis via excitation of a pesticide by absorbing natural or artificial sunlight in order to know its basic photochemistry, and indirect photolysis meaning either sensitization by dissolved organic matters or oxidation by reactive oxygen species is basically excluded. Several experimental approaches including spectroscopic techniques together with theoretical calculations are first discussed from the viewpoint of the reaction mechanisms in direct photolysis. Then, the typical photoreactions of pesticides are summarized by chemical classes and/or functional groups and discussed as far as possible in relation to their mechanisms.

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Photocyclization of Stilbenes and Related Molecules

1984

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On irradiation in solution with ultraviolet (UV) light, cis ‐stilbene undergoes reversible photocyclization to give trans ‐4a,4b‐dihydrophenanthrene, an intermediate that can be trapped oxidatively with hydrogen acceptors such as iodine, oxygen, or tetracyanoethylene to give phenanthrene in high yield. This type of photoreaction occurs with a wide range of substituted stilbenes and related molecules, including various polycyclic and heterocyclic analogs; in addition, certain systems with a single heteroatom (nitrogen, oxygen, or sulfur) in place of the central π bond undergo photocyclization, creating a new five‐membered heterocyclic ring. In some of these photocyclizing systems, the transient dihydroaromatic intermediates are trapped without added oxidants by the elimination of suitable leaving groups or by various hydrogen shifts. Photocyclization is the preferred method for the synthesis of many different polynuclear aromatic systems. The discovery and early development of stilbene photocyclization has been surveyed, and several other general reviews have appeared.

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Synthesis and photocyclization of some 4‐(5)arylethenylimidazoles

Abstract: The synthesis of eleven 4‐(5)arylethenylimidazoles and their separation into cis and trans isomers is described. Ir, uv, nmr, and mass spectrometric data of the compounds are given. The photocyclization of the unsubstituted and p‐substituted compounds is reported.

Cited by 8 publications

References 17 publications

Oxidation of Free L-histidine by tert-Butylhydroperoxide

Oxidation of Free L-histidine by tert-Butylhydroperoxide

Direct photolysis mechanism of pesticides in water

Photocyclization of Stilbenes and Related Molecules

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