Photoelectrochemical C−H Alkylation of Heteroarenes with Organotrifluoroborates

Yan, Hong; Hou, Zhufeng; Xu, Hai‐Chao

doi:10.1002/ange.201814488

Cited by 88 publications

(28 citation statements)

References 64 publications

(15 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, the Xu group has demonstrated the feasibility of cross coupling inside an EPC framework by employing routinely used organotrifluoroborates and an acridinium catalyst. 109 Lin et al described the application of EPC for the oxidation of alcohols via riboflavin tetraacetate (RFT) and thiourea catalysis ( Figure 28 ). 110 In the catalytic cycle, the RFT catalyst is first photoexcited to RFT* and subsequently reacts with thiourea 28 - 2 to generate semiquinone form RFT • -H and thiyl radical 28 - 4 .…”

Section: Electrophotochemistrymentioning

confidence: 99%

New Redox Strategies in Organic Synthesis by Means of Electrochemistry and Photochemistry

et al. 2020

View full text Add to dashboard Cite

As the breadth of radical chemistry grows, new means to promote and regulate single-electron redox activities play increasingly important roles in driving modern synthetic innovation. In this regard, photochemistry and electrochemistry—both considered as niche fields for decades—have seen an explosive renewal of interest in recent years and gradually have become a cornerstone of organic chemistry. In this Outlook article, we examine the current state-of-the-art in the areas of electrochemistry and photochemistry, as well as the nascent area of electrophotochemistry. These techniques employ external stimuli to activate organic molecules and imbue privileged control of reaction progress and selectivity that is challenging to traditional chemical methods. Thus, they provide alternative entries to known and new reactive intermediates and enable distinct synthetic strategies that were previously unimaginable. Of the many hallmarks, electro- and photochemistry are often classified as “green” technologies, promoting organic reactions under mild conditions without the necessity for potent and wasteful oxidants and reductants. This Outlook reviews the most recent growth of these fields with special emphasis on conceptual advances that have given rise to enhanced accessibility to the tools of the modern chemical trade.

show abstract

Section: Electrophotochemistrymentioning

confidence: 99%

New Redox Strategies in Organic Synthesis by Means of Electrochemistry and Photochemistry

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Xu reported the C-H alkylation of heteroarenes with trifluoroborates under e-PRC ( Figure 8). 47 Photoexcited 9-mesityl-10-methylacridinium (Mes-Acr + ) is a potent oxidant (E p red = +2.06 V vs. SCE) capable of SET oxidation of isopropyl trifluoroborate 26 (E p ox = ca. +1.50 V vs. SCE) 48 to its 2 o alkyl radical.…”

Section: Replacing Sacrificial Redox Agents With Currentmentioning

confidence: 99%

“…So far, synthetic photoelectrochemistry examples herein have been conducted in custom-built (transparent) electrochemical reaction vessels. These generally fall into two categories ( Figure 16): a) an undivided glass 'pot cell' / 'beaker cell' / undivided glass voltammetry setup, 35,47,53,58,61,63 or b) a divided glass 'H-type' cell with a glass or membrane frit. 39,49,52,63 These are all standard academic reactors used for SOE, 66 which can be easily irradiated with visible light.…”

Section: Practical Execution and Experimental Rigormentioning

confidence: 99%

Synthetische Photoelektrochemie

Barham

Koenig

2020

Angewandte Chemie

View full text Add to dashboard Cite

Photoredox Catalysis (PRC) and Synthetic Organic Electrochemistry (SOE) are often considered competing technologies in organic synthesis. Their fusion has been largely overlooked. We review state-of-the-art synthetic organic photoelectrochemistry, grouping examples into three categories: 1) electrochemically-mediated PhotoRedox Catalysis (e-PRC), 2) decoupled PhotoElectroChemistry (dPEC) and 3) interfacial PhotoElectroChemistry (iPEC). Such synergies prove beneficial not only for synthetic 'greenness' and chemical selectivity, but also in the accumulation of energy for accessing super-oxidizing or reducing single-electron-transfer (SET) agents. Opportunities and challenges in this emerging and exciting field are discussed.

show abstract

“…We coined the general nomenclature "electrochemically-mediated PhotoRedox Catalysis (e-PRC)" as a blanket term to cover both net-oxidative and net-reductive variants (29) and to avoid misunderstanding with iPEC. e-PRC leverages the unique benefits of both parent technologies PRC and SOE in order to i) compile potential and photon energies to achieve photocatalyst excited-state potentials beyond those normally accessible via visible light photons alone (44)(45)(46)51) and to ii) obviate the need for sacrificial oxidants/reductants. (48,50) Pioneering reports on e-PRC realized these benefits in a number of net-reductive/net-oxidative transformations.…”

mentioning

confidence: 99%

“…(48,50) Pioneering reports on e-PRC realized these benefits in a number of net-reductive/net-oxidative transformations. (44)(45)(46)(47)(48)(49)(50)(51) In the net-oxidative direction , previous examples of electroactivated PhotoRedox Catalysts (e-PRCats) include i) 9-mesityl-10-methylacridinium dye, (44) ii) phenothiazine (40) (Figure 1).…”

mentioning

confidence: 99%

Hole-Mediated PhotoRedox Catalysis: Tris(p-Substituted)biarylaminium Radical Cations as Tunable, Precomplexing and Potent Photooxidants

Wu¹,

Zurauskas²,

Domański³

et al. 2020

Preprint

View full text Add to dashboard Cite

Electrochemically-mediated Photoredox Catalysis emerged as a powerful synthetic technique in recent years, overcoming fundamental limitations of electrochemistry and photoredox catalysis in the single electron transfer activation of small organic molecules. However, the mechanism of how photoexcited radical ion species with ultrashort (picosecond-order) lifetimes could ever undergo productive photochemistry has eluded synthetic chemists. We report tri(para-substituted)biarylamines as a tunable class of electroactivated photocatalysts that become superoxidants in their photoexcited states, even able to oxidize molecules (such as dichlorobenzene and trifluorotoluene) beyond the solvent window limits of cyclic voltammetry. Furthermore, we demonstrate that precomplexation not only permits the excited state photochemistry of tris(para-substituted)biarylaminium cations, but enables and rationalizes the surprising photochemistry of their higher-order doublet (Dn) excited states.

show abstract

Photoelectrochemical C−H Alkylation of Heteroarenes with Organotrifluoroborates

Cited by 88 publications

References 64 publications

New Redox Strategies in Organic Synthesis by Means of Electrochemistry and Photochemistry

New Redox Strategies in Organic Synthesis by Means of Electrochemistry and Photochemistry

Synthetische Photoelektrochemie

Hole-Mediated PhotoRedox Catalysis: Tris(p-Substituted)biarylaminium Radical Cations as Tunable, Precomplexing and Potent Photooxidants

Contact Info

Product

Resources

About