Photoinduced electron transfer oxygenations

Lopez, Luigi

doi:10.1007/3-540-52379-0_5

Cited by 27 publications

(7 citation statements)

References 208 publications

(323 reference statements)

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“…71 In the 1980s, the Schaap group discovered that biphenyl provided a dramatic rate increase to the DCA-catalyzed oxidation of cyclopropanes, 72 epoxides, 73–76 and aziridines. 77 For example, the photooxygenation of epoxide 19 to 20 is a slow reaction upon photocatalysis using DCA alone (Scheme 2).…”

Section: Photoinduced Electron Transfermentioning

confidence: 99%

Dual Catalysis Strategies in Photochemical Synthesis

2016

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The interaction between an electronically excited photocatalyst and an organic molecule can result in the genertion of a diverse array of reactive intermediates that can be manipulated in a variety of ways to result in synthetically useful bond constructions. This Review summarizes dual-catalyst strategies that have been applied to synthetic photochemistry. Mechanistically distinct modes of photocatalysis are discussed, including photoinduced electron transfer, hydrogen atom transfer, and energy transfer. We focus upon the cooperative interactions of photocatalysts with redox mediators, Lewis and Brønsted acids, organocatalysts, enzymes, and transition metal complexes.

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Section: Photoinduced Electron Transfermentioning

confidence: 99%

Dual Catalysis Strategies in Photochemical Synthesis

2016

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“…This difference makes direct reactions between organic molecules and O 2 in their ground states spin-forbidden. To facilitate this process, a suitable catalyst, either organic or inorganic, may be used to convert ground state O 2 into reactive oxygen species (ROS), including singlet oxygen ( 1 O 2 ), by spin-allowed photosensitization. − Competing with this energy transfer, photoinduced electron transfer may also take place and stimulate the activation of both O 2 and substrates and the formation of ROS or substrate radical ions …”

Section: Introductionmentioning

confidence: 99%

“…2−6 Competing with this energy transfer, photoinduced electron transfer may also take place and stimulate the activation of both O 2 and substrates and the formation of ROS or substrate radical ions. 7 Oxidation of sulfides is a typical oxidation reaction and has attracted tremendous research attention recently. 8 The oxidation of sulfides is an important chemical process and has significant application in production of medicine, 9 precombustion desulfurization of fuels, 10,11 innocent treatment of wastewater 12,13 and chemical warfare agents, 13,14 etc.…”

Section: ■ Introductionmentioning

confidence: 99%

Flavin Dibromide as an Efficient Sensitizer for Photooxidation of Sulfides

Dang

Zhu

Guo

et al. 2018

ACS Sustainable Chem. Eng.

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Flavin derivatives (FLs) are the building blocks and functional groups within many enzymes that absorb strongly in the visible light region and are redox cofactors in a large number of biological processes. We directly attached Br atoms into the conjugated framework of FL to afford FL dibromide (DBFL) and expected the heavy atom effect of Br to facilitate the intersystem crossing of excited FLs to reach the triplet states for efficient sensitization of O2. Compared with FL (ε = 1.01 × 104 M–1 cm–1 at 441 nm), DBFL shows stronger absorption in the visible range (ε = 1.90 × 104 M–1 cm–1 at 450 nm). The singlet oxygen quantum yield of DBFL is enhanced from 55.3% in FL to 92.2% at the expense of decreased luminance quantum yield from 37.7% in FL to 5.5%, confirming that a large portion of the excited DBFL molecules evolves into triplet excited states. Both FL and DBFL were used in photosensitized oxidation of various sulfides to afford corresponding sulfoxides. DBFL exhibits a twofivefold performance enhancement with respect to FL in sensitizing O2 for photocatalytic oxidation. In addition, the oxidation of sulfides with DBFL was found efficient and led exclusively to sulfoxides, with no secondary oxidation products observed. Mechanistic investigations showed that both singlet oxygen and superoxide anion radical are formed as reactive oxygen species. The findings pave the way for design and application of novel organic sensitizers for photocatalytic oxidation.

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“…It consisted of two steps: a) reductive coupling of two properly selected ketones( 1 and 2)u nder McMurry conditions, [13] andb )photooxygenation [14] of the obtained tetrasubstituted alkene 3 to provide the desired 1,2-dioxetane 4. It consisted of two steps: a) reductive coupling of two properly selected ketones( 1 and 2)u nder McMurry conditions, [13] andb )photooxygenation [14] of the obtained tetrasubstituted alkene 3 to provide the desired 1,2-dioxetane 4.…”

Section: Introductionmentioning

confidence: 99%

“…The synthetic approacht ot hermochemiluminescent 1,2-dioxetanes 4 is depictedi nS cheme 2. It consisted of two steps: a) reductive coupling of two properly selected ketones( 1 and 2)u nder McMurry conditions, [13] andb )photooxygenation [14] of the obtained tetrasubstituted alkene 3 to provide the desired 1,2-dioxetane 4.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of 1,2‐Dioxetanes as Thermochemiluminescent Labels for Ultrasensitive Bioassays: Rational Prediction of Olefin Photooxygenation Outcome by Using a Chemometric Approach

Andronico

Quintavalla

Lombardo

et al. 2016

Chemistry A European J

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Great interest in new thermochemiluminescent (TCL) molecules, for example, in bioanalytical assays, has prompted the design and synthesis of a small library of more than 30 olefins to be subjected to photooxygenation, with the aim of obtaining new 1,2-dioxetane-based TCL labels with optimized properties. Fluorine atoms on the acridan system remarkably stabilize 1,2-dioxetanes when they are located in the 3- and/or 6-position (4 h and 4 i). On the other hand, 2,7-difluorinated acridan dioxetane (4 j) showed a significantly enhanced fluorescence quantum yield with respect to the unsubstituted dioxetane (4 a). Some of the synthesized olefins did not undergo singlet oxygen addition and a rationale was sought to ease the photooxygenation step, leading to the TCL dioxetanes. A chemometric approach has been adopted to exploit principal component analysis and linear discriminant analysis of the structural and electronic molecular descriptors obtained by DFT optimizations of olefins 3. This approach allows the steric and electronic parameters that govern dioxetane formation to be revealed.

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Photoinduced electron transfer oxygenations

Cited by 27 publications

References 208 publications

Dual Catalysis Strategies in Photochemical Synthesis

Dual Catalysis Strategies in Photochemical Synthesis

Flavin Dibromide as an Efficient Sensitizer for Photooxidation of Sulfides

Synthesis of 1,2‐Dioxetanes as Thermochemiluminescent Labels for Ultrasensitive Bioassays: Rational Prediction of Olefin Photooxygenation Outcome by Using a Chemometric Approach

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