Electrophotocatalytic S_NAr Reactions of Unactivated Aryl Fluorides at Ambient Temperature and Without Base

Abstract

The electrophotocatalytic SNAr reaction of unactivated aryl fluorides at ambient temperature without strong base is demonstrated.

Synthetische Photoelektrochemie

“…88 To simplify the technology for users, this review sets precedent for grouping historic and recent reports into three categories of photoelectrochemistry: electrochemically-mediated PhotoRedox Catalysis (e-PRC), decoupled PhotoElectroChemistry (dPEC) and interfacial PhotoElectroChemistry (iPEC). The fundamental advantages that derive from the fusion of PRC and SOE are expected to: 1) broadens the accessible 'redox window' of SET chemistry, 35,38,39 2) enables milder conditions that allow greater functional group tolerance and chemoselectivity 49,52,57 and 3) increases energy savings and atom economy. 60,64 Practical challenges in execution of synthetic photoelectrochemistry could be addressed by an equipment and expertise interface with research fields of photoelectrochemical cells for water splitting and photovoltaic cells, while flow chemistry is expected to offer significant benefits to the transmission of light/electrons, 76,77 kinetics and scalability of photoelectrochemical reactions.…”

“…Lambert reported SNAR reactions of unactivated aryl fluorides under e-PRC ( Figure 9). 49 Here, photoexcited 2,3-dichloro-5,6dicyanoquinone (DDQ) was sufficiently oxidizing (E p red = +3.18 V vs. SCE) to engage chlorofluoroarenes such as 32 in SET oxidation. In terms of heteroarene partner, the substrate scope was similar to the previous report involving photoexcited dication *TAC •2+ .…”

“…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. It is widely accepted that one of the drivers behind the 'renaissances' of PRC and SOE in the last decade is the availability of reactor equipment.…”

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

“…(38)(39) A third category involves an intimate and synergistic relationship of photo-and electrochemical steps within the same catalytic cycle. (40-51) A variety of nomenclature has been coined in the literature for this sub-category of PEC, such as: "electrophotocatalysis" (45-47,51) "photoelectrocatalysis" (46,50) and "electron-primed photoredox catalysis" (51). 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.…”

“…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.…”