Benzimidazolium Naphthoxide Betaine Is a Visible Light Promoted Organic Photoredox Catalyst

Hasegawa, Eietsu; Izumiya, Norihiro; Miura, Tomoaki; Ikoma, Tadaaki; Iwamoto, Hajime; Takizawa, Shin‐ya; Murata, Shigeru

doi:10.1021/acs.joc.8b00282

Cited by 42 publications

(30 citation statements)

References 64 publications

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“…Recently, a zwitterionic visible‐light‐absorbing benzimidazolium naphtholate BINA was successfully employed in photocatalytic deiodination and desulfonylation reactions in the presence of a combined electron and hydrogen atom donor 10 (see Scheme 10). [77] The cationic benzimidazolium moiety can be considered as separated from the naphtholate, since the tilted structure prevents π‐conjugation. The photocatalytic activity was studied using different solvents with attributed Lewis‐basic or Lewis‐acidic characters, as estimated by donor and acceptor numbers.…”

Section: Anionic Compounds As Photocatalystsmentioning

confidence: 99%

“…Recently,azwitterionic visible-light-absorbing benzimidazolium naphtholate BINA was successfully employed in photocatalytic deiodination and desulfonylation reactions in the presence of ac ombined electron and hydrogen atom donor 10 (see Scheme 10). [77] Thec ationic benzimidazolium moiety can be considered as separated from the naphtholate, since the tilted structure prevents p-conjugation. Thep hotocatalytic activity was studied using different solvents with attributed Lewis-basic or Lewis-acidic characters,a se stimated by donor and acceptor numbers.T he authors concluded that Lewis-basic solvents cause tight interactions with the Lewis-acidic benzimidazolium moiety,w hereas the electronic properties of the Lewis-basic naphtholate anion are less governed, thereby resulting in an increased electrondonating ability.The best results (Scheme 9) were found using DMF as solvent.…”

Section: Naphtholate-catalyzed Dehalogenation and Detosylationmentioning

confidence: 99%

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Excited State Anions in Organic Transformations

2020

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Utilizing light is a smart way to fuel chemical transformations as it allows the energy to be selectively focused on certain molecules. Many reactions involving electronically excited species proceed via open‐shell intermediates, which offer novel and unique routes to expand the hitherto used synthetic toolbox in organic chemistry. The direct conversion of non‐prefunctionalized, less activated compounds is a highly desirable goal to pave the way towards more sustainable and atom‐economic chemical processes. Photoexcited closed‐shell anions have been shown to reach extreme potentials in single electron transfer reactions and reveal unusual excited‐state reactivity. It is, therefore, surprising that their use as a reagent or photocatalyst is limited to a few examples. In this Review, we briefly discuss the characteristics of anionic photochemistry, highlight pioneering work, and show recent progress which has been made by utilizing photoexcited anionic species in organic synthesis.

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Section: Anionic Compounds As Photocatalystsmentioning

confidence: 99%

Section: Naphtholate-catalyzed Dehalogenation and Detosylationmentioning

confidence: 99%

Excited State Anions in Organic Transformations

2020

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“…As econd controle xperiment in the absence of ( Me PMP Me ) 3 ZrCl showed slow conversion to the dehalogenated product consistent with the observation that BIH derivatives can undergo photochemical reactions in the absence of photosensitizers. [87,88] However, the reduced rate of conversionc learly shows that ( Me PMP Me ) 3 ZrCl acts as ap hotosensitizer in this transformation.…”

Section: Photoredox Catalysismentioning

confidence: 99%

Photoluminescence of Seven‐Coordinate Zirconium and Hafnium Complexes with 2,2′‐Pyridylpyrrolide Ligands

Zhang

Akhmedov

Petersen

et al. 2019

Chemistry A European J

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Luminescents even-coordinated zirconium and hafniumc omplexes bearing three mono-anionic 2,2'-pyridylpyrrolide ligands and one chloride weres ynthesized.S olidstate structures and the dynamicb ehaviors in solutionw ere probed by X-ray crystallography and variable temperature 1 HNMR experiments, respectively.A bsorption spectroscopy and time-dependent density functional theory( TD-DFT) calculations supported ah ybrid of ligand-to-metal charge transfer( LMCT)/ligand-to-ligand charge transfer (LLCT)f or the visible light absorption band. The complexes ( Me PMP Me ) 3 MCl (M = Zr,H f, Me PMP Me = 3,5-dimethyl-2-(2-pyridyl)pyrrolide) are emissive in solution at room temperature upon irradiation with visible light due to ac ombination of phosphorescence and fluorescencec haracterizedb ye xcited state lifetimes in the msa nd low to sub-ns timescale,r espectively.E lectrochemicale xperiments revealed that the zirconium complex possesses ar eversible redox event under highly reducingcondition (À2.29 Vv s. Fc + /0 ).

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“…Additional experimental validation was provided by performing nanosecond time-resolved spectroscopy (transient absorption spectra;F igure 5a). [27,28] detectable evidence of al ong-lived transient species (Figure 5b). Thel ifetime of the transient species of 1 was markedly shortened under air (t = 0.15 ms), indicating that it was at riplet species (Supporting Information, Figure S7).…”

Section: Resultsmentioning

confidence: 99%

Unveiling Latent Photoreactivity of Imines

et al. 2020

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Unlike carbonyl compounds, it has long been common understanding that excited imines show virtually no photoreactivity, and hence their properties and potential utility in chemical science remain largely unexplored. Now, a strategy is presented for eliciting latent photoreactivity of imines based on the introduction of a donor–acceptor (D‐A) structure to extend the lifetime of their photoexcited states. A series of spectroscopic analyses and density functional theory calculations reveal unique photophysical properties of the D‐A‐type imines. Furthermore, the reactivity of the D‐A‐type imines is demonstrated by using them as a photoredox catalyst for atom‐transfer radical addition. These findings illuminate a previously neglected chemical space in the field of photochemistry, which will be exploited by taking advantage of the inherent structural modularity of imines.

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Benzimidazolium Naphthoxide Betaine Is a Visible Light Promoted Organic Photoredox Catalyst

Cited by 42 publications

References 64 publications

Excited State Anions in Organic Transformations

Excited State Anions in Organic Transformations

Photoluminescence of Seven‐Coordinate Zirconium and Hafnium Complexes with 2,2′‐Pyridylpyrrolide Ligands

Unveiling Latent Photoreactivity of Imines

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