On the photochemical reaction of pyridinium salts with nucleophiles

D’Auria, Maurizio

doi:10.1007/s43630-021-00070-6

Cited by 6 publications

(3 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For this reason, we started a research project devoted to find a lower chaotic description of the reactivity of this type of compounds. However, previous results in this field indicate the presence of a relatively complex frame: in the reaction of pyridinium salts with nucleophiles the observed reaction can be explained admitting the formation of a Dewar isomer [39]; in the case of the reaction with nucleophiles of pyrilium salts, the formation of cyclopentene epoxide cation is favored [40], while in the isomerization of 2,6-dimethylpyrazine, Dewar isomers or benvalene isomers can account for the reaction [41]. Continuing our efforts in this field, we want to describe the results of our calculations on the isomerization of pyridazine N-oxides.…”

Section: Scheme 1 Photochamical Isomerization Of Pyridinementioning

confidence: 96%

The Photochemical Isomerization in Pyridazine-N-oxide Derivatives

D’Auria,

Emanuele

2024

Preprint

View full text Add to dashboard Cite

DFT calculations on the photoisomerization reactions of pyridazine N-oxide derivatives are presented. The irradiation of 3,6-diphenylpyridazine N-oxide allowed to obtain the first excited singlet state that underwent to a ring opening reaction induced to the oxygen migration to the adjacent carbon atom, with the formation of a diazo derivative. This intermediate can give a ring closure reaction to give a pyrazole derivative, or, with a higher transition energy, it can lose nitrogen allowing the formation of 2,5-diphenylfuran. The irradiation of 3-phenylpyridazine N-oxide allowed the formation only of 2-phenylfuran. In this case, calculations allowed to explain this behavior. The first excited singlet state gave a photoisomerization reaction with the formation of the corresponding diazo intermediate. This intermediate could not be converted into the corresponding pyrazole derivative because it was converted into a N-formyl pyrazole never reported in literature. The only possible reaction is the loss of nitrogen and the formation of 2-phenylfuran.

show abstract

Section: Scheme 1 Photochamical Isomerization Of Pyridinementioning

confidence: 96%

The Photochemical Isomerization in Pyridazine-N-oxide Derivatives

D’Auria,

Emanuele

2024

Preprint

View full text Add to dashboard Cite

show abstract

“…4 Also, in modern synthetic chemistry, photoinduced chemical transformations play a significant role due to sustainability. 5 The conventional organic photochemical reactions like Norrish type I, 6 Norrish type II, 7 Paternò–Büchi reactions, 8 etc. are generally performed using UV light.…”

Section: Introductionmentioning

confidence: 99%

Catalyst-Free Photoinduced C–C Bond Formations

2023

View full text Add to dashboard Cite

Use of sustainable energy sources in synthetic organic chemistry has become one of the popular research topics, due to environmental pollution and global warming. In this review, we have made a collection of literature that covers photocatalyst-free and transition metal-free light-induced reactions for the construction of carbon-carbon (C-C) bonds. The reaction systems discussed here are C-C bond formation via carbene intermediate, radical intermediate, and miscellaneous illustration via cyclization.

show abstract

“…34 35 Classically, the PB reaction is promoted by ultraviolet light and limited to specific pairings of electron-rich aryl carbonyls and olefins. 36 37 38 39 40 41 42 Modern innovations have developed visible-light-facilitated PB reactions, sometimes relying on triplet energy transfer from a photosensitizer, but are generally limited to activated carbonyls such as arylglyoxylates. 43 44 45 46 47 48 A brief selection of recent alternative photochemical methods to access oxetanes include Cu-catalyzed [2+2]-cycloaddition, 49 oxonium ylide promoted ring contraction, 50 and alcohol C–H functionalization followed by nucleophilic substitution.…”

mentioning

confidence: 99%

Ketyl Radical Enabled Synthesis of Oxetanes

Schindler,

Gatazka,

Parikh

et al. 2024

Synthesis

View full text Add to dashboard Cite

Oxetanes, 4-membered oxygen-containing heterocycles, were identified to have pharmaceutical applications after the discovery of the chemotherapeutic drug taxol (Paclitaxel) and its analogues. Furthermore, oxetanes have been identified as bioisosteres for several common functional groups and are present in a number of natural products. However, oxetanes are one of the least common oxygen-containing heterocycles in active pharmaceutical ingredients on the market, which can be attributed, in part, due to challenges with their synthesis. Previous strategies rely on nucleophilic substitutions or [2+2]-cycloadditions, but are limited by the stepwise buildup of starting material and limitations in scope resulting from requirements for activated substrates. To address these limitations, we envisioned activating simple carbonyls to their corresponding α-oxy iodides to promote ketyl radical formation. These radicals can then undergo atom-transfer radical addition with alkenes followed by one-pot nucleophilic substitution to produce oxetanes. Herein, we present a proof-of-principle of this strategy in which fluoroalkyl carbonyls are successfully converted into the corresponding fluoroalkyl oxetanes.

show abstract

On the photochemical reaction of pyridinium salts with nucleophiles

Cited by 6 publications

References 26 publications

The Photochemical Isomerization in Pyridazine-N-oxide Derivatives

The Photochemical Isomerization in Pyridazine-N-oxide Derivatives

Catalyst-Free Photoinduced C–C Bond Formations

Ketyl Radical Enabled Synthesis of Oxetanes

Contact Info

Product

Resources

About