Photooxygenations of nitrogen heterocycles

George, M. V.; Bhat, Vikram

doi:10.1021/cr60321a003

Cited by 72 publications

(22 citation statements)

References 44 publications

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“…1 O 2 is known to undergo a variety of reactions with nitrogen heterocycles [18] and might thus attack the emitters, leading to the formation of a variety of deterioration products. We therefore performed the irradiation experiments in different solvents under atmospheric as well as inert conditions (freeze-pump-thaw, then argon atmosphere).…”

Section: Resultsmentioning

confidence: 99%

Studies on the photodegradation of red, green and blue phosphorescent OLED emitters

Schmidbauer¹,

Hohenleutner²,

König³

2013

Beilstein J. Org. Chem.

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SummaryThe photodegradation behavior of four well-established iridium emitters was investigated. Irradiation of the samples in different solvents and under atmospheric as well as inert conditions helped to identify several pathways that can contribute to the deterioration of these compounds. Degradation via singlet oxygen or the excited states of the emitters as well as the detrimental influence of halogenated solvents are discussed for the different investigated iridium complexes. Some of the resulting degradation products could be identified by using LC–MS or other analytical techniques. The results show how even small structural changes can have a huge influence on rate and mechanism of the photodegradation. The observations from this study may help to better understand degradation processes occurring during the handling of the materials, but also during device processing and operation.

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Section: Resultsmentioning

confidence: 99%

Studies on the photodegradation of red, green and blue phosphorescent OLED emitters

Schmidbauer¹,

Hohenleutner²,

König³

2013

Beilstein J. Org. Chem.

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“…While currently still underutilized, it offers a convenient method to introduce novel structural motifs. 22 For example, Cossy and Belotti used a photooxygenation for the preparation of quinoline-5,8-quinones, 23 and Prisinzano et al generated salvidivin A from salvinorin A by exposure to sun light. 24 The reaction of 1 under ambient laboratory light generated the novel 7-iminothieno[3,2- c ]pyridine-4,6(5 H ,7 H )-dione 13 , but the conversion was incomplete with a significant amount of 1 left after 2 days (entry 1).…”

mentioning

confidence: 99%

Photooxygenation of an amino-thienopyridone yields a more potent PTP4A3 inhibitor

et al. 2016

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The phosphatase PTP4A3 is an attractive anticancer target, but knowledge of its exact role in cells remains incomplete. A potent, structurally novel inhibitor of the PTP4A family was obtained by photooxygenation of a less active, electron-rich thienopyridone (1). Iminothienopyridinedione 13 displays increased solution stability and is readily obtained by two new synthetic routes that converge in the preparation of 1. The late-stage photooxygenation of 1 to give 13 in high yield highlights the potential of this reaction to modify the structure and properties of a biological lead compound and generate value for expanding the scope of an SAR investigation. Analog 13 should become a valuable tool for further exploration of the role of PTP4A3 in tumor progression.

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“…This bond is easily reduced to a secondary amine by the addition of sodium cyanoborohydride. To confirm that 4 (5) imidazolecarboxaldehyde demonstrates this propensity to form a Schiff base with primary amines, it was incubated with the model peptide, KYK. Characterization of the reaction mixture by LC/MS after incubation at 37°C for 1 h produced the expected mass of 438.2m/z.…”

Section: Reaction Of 4(5) Imidazolecarboxaldehyde With a Tripeptidementioning

confidence: 99%

“…The byproduct(s) responsible for producing the yellow color have not been elucidated in any publications, although its presence has been noted in publications describing protein formulations (1). L-histidine is susceptible to singlet molecular oxygen-mediated photooxidation, which is also known as the "photodynamic effect" (2)(3)(4)(5). The attack by singlet oxygen on Lhistidine occurs at the imidazole ring via unstable endoperoxide intermediates (6,7), resulting in a large variety of products, most of which are unstable and occur as intermediates for the overall reaction.…”

Section: Introductionmentioning

confidence: 99%