A comparison of hydrogen bonding solvent effects on the singlet oxygen reactions of allyl and vinyl sulfides, sulfoxides, and sulfones

Stensaas, Kristina L.; McCarty, Brent V.; Touchette, Natacha M.; Brock, James B

doi:10.1016/j.tet.2006.08.084

Cited by 18 publications

(12 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Tiglic acid derivatives result in regioisomeric hydroperoxide ratios of 95:5 up to 98:2. This effect was also observed for α,β-unsaturated nitriles [23] sulfoxides [24], and sulfonates [25]. Also the corresponding dimethylstyrene showed gem-selectivity [26].…”

Section: Singlet Oxygen Reactivity Modesmentioning

confidence: 82%

Singlet oxygen and natural substrates: functional polyunsaturated models for the photooxidative degradation of carotenoids

Griesbeck

Kleczka

Kiff

et al. 2015

Pure and Applied Chemistry

View full text Add to dashboard Cite

The primary chemical reactions of singlet molecular oxygen with polyunsaturated carotenoids are the focus of this research report. Model compounds that exhibit electronic properties and substituent pattern similar to natural carotenes, xanthophylls or apocarotenoids, respectively, were investigated with regard to photooxygenation reactivity. For dienes and trienes as substrates, high tandem reactivity was observed and hydroperoxy-endoperoxides were isolated as the secondary products of singlet oxygen reaction. The electronic gem-effect on the regioselectivity of the ene reaction is conserved also in vinylogous positions and thus appears to originate from a radical-stabilizing effect. In an attempt to combine different peroxide groups derived from natural products as a tool for new pharmaceutically active products, a dyade synthesis of an artemisinine-safranol with subsequent singlet oxygen addition was realized.

show abstract

Section: Singlet Oxygen Reactivity Modesmentioning

confidence: 82%

Singlet oxygen and natural substrates: functional polyunsaturated models for the photooxidative degradation of carotenoids

Griesbeck

Kleczka

Kiff

et al. 2015

Pure and Applied Chemistry

View full text Add to dashboard Cite

show abstract

“…Even the oxidation of 1 f was enhanced to 44 % conversion with this catalyst loading (see entries 11 and 12 in Table ). The reluctant reaction of diaryl sulfides with 1 O 2 compared to aryl alkyl and dialkyl sulfides has been previously reported and could be related to the electrophilic nature of singlet oxygen . In other words, 1 O 2 has a low‐energy LUMO (

π_{y}^{*}

) compared to 3 O 2 and hence reacts more readily with sulfides having electron‐rich S atoms (alkyl sulfides) to form relatively stable persulfoxide intermediates (see mechanism in Scheme ).…”

Section: Resultsmentioning

confidence: 99%

Selective Photooxidation of Sulfides Catalyzed by Bis‐cyclometalated Ir^III Photosensitizers Bearing 2,2′‐Dipyridylamine‐Based Ligands

Vaquero

Ruiz-Riaguas

Martı́nez-Alonso

et al. 2018

Chemistry A European J

View full text Add to dashboard Cite

A new family of heteroleptic bis-cyclometalated Ir complexes with formula [Ir(CN^ ) (NN^ )]Cl (CN^ =2-phenylpyridinate and NN^ =2,2'-dipyridylamine or N-benzylated 2,2'-dipyridylamines, were synthesized, characterized, and successfully used as photosensitizers in the catalytic photooxidation of an array of dialkyl, dibenzyl, alkyl aryl, and diaryl sulfides, as well as sulfur-containing amino acids. Furthermore, the reactions proceeded with optimal chemoselectivity, and atom economy under mild conditions. Experimental observations support a dual mechanism in which singlet oxygen and superoxide are the actual oxidants.

show abstract

“…2) Oxidation . As detailed in Scheme , we propose that the oxidation of benzylamine by 1 O 2 , first, involves the formation of a charge‐transfer exciplex between singlet oxygen and the amine based on the electrophilic nature of singlet oxygen and the nucleophilic character of the amine substrate. This step is followed by two sequential single electron transfer (SET) steps and two internal proton transfer (PT) processes and gives rise to the primary aldimine and one molecule of H 2 O 2 .…”

Section: Resultsmentioning

confidence: 99%

Non‐emissive Ru^II Polypyridyl Complexes as Efficient and Selective Photosensitizers for the Photooxidation of Benzylamines

Yagüe

Echevarría

Vaquero

et al. 2020

Chemistry A European J

View full text Add to dashboard Cite

Five new RuII polypyridyl complexes bearing N‐(arylsulfonyl)‐8‐amidoquinolate ligands and three of their biscyclometalated IrIII congeners have been prepared and employed as photocatalysts (PCs) in the photooxidation of benzylamines with O2. In particular, the new RuII complexes do not exhibit photoluminescence, rather they harvest visible light efficiently and are very stable in solution under irradiation with blue light. Their non‐emissive behavior has been related to the low electrochemical energy gaps and rationalized on the basis of theoretical calculations (DFT analysis) that predict low S0←T1 energy values. Moreover, the RuII complexes, despite being non‐emissive, display excellent activities in the selective photocatalytic transformation of benzylamines into the corresponding imines. The presence of an electron‐withdrawing group (‐CF3) on the arene ring of the N‐(arylsulfonyl)‐8‐amidoquinolate ligand improves the photocatalytic activity of the corresponding photocatalyst. Furthermore, all the experimental evidence, including transient absorption spectroscopy measurements suggest that singlet oxygen is the actual oxidant. The IrIII analogues are considerably more photosensitive and consequently less efficient photosensitizers (PSs).

show abstract

A comparison of hydrogen bonding solvent effects on the singlet oxygen reactions of allyl and vinyl sulfides, sulfoxides, and sulfones

Cited by 18 publications

References 14 publications

Singlet oxygen and natural substrates: functional polyunsaturated models for the photooxidative degradation of carotenoids

Singlet oxygen and natural substrates: functional polyunsaturated models for the photooxidative degradation of carotenoids

Selective Photooxidation of Sulfides Catalyzed by Bis‐cyclometalated Ir^III Photosensitizers Bearing 2,2′‐Dipyridylamine‐Based Ligands

Non‐emissive Ru^II Polypyridyl Complexes as Efficient and Selective Photosensitizers for the Photooxidation of Benzylamines

Contact Info

Product

Resources

About

A comparison of hydrogen bonding solvent effects on the singlet oxygen reactions of allyl and vinyl sulfides, sulfoxides, and sulfones

Cited by 18 publications

References 14 publications

Singlet oxygen and natural substrates: functional polyunsaturated models for the photooxidative degradation of carotenoids

Singlet oxygen and natural substrates: functional polyunsaturated models for the photooxidative degradation of carotenoids

Selective Photooxidation of Sulfides Catalyzed by Bis‐cyclometalated IrIII Photosensitizers Bearing 2,2′‐Dipyridylamine‐Based Ligands

Non‐emissive RuII Polypyridyl Complexes as Efficient and Selective Photosensitizers for the Photooxidation of Benzylamines

Contact Info

Product

Resources

About

Selective Photooxidation of Sulfides Catalyzed by Bis‐cyclometalated Ir^III Photosensitizers Bearing 2,2′‐Dipyridylamine‐Based Ligands

Non‐emissive Ru^II Polypyridyl Complexes as Efficient and Selective Photosensitizers for the Photooxidation of Benzylamines