Electron transfer, naphthalene radical anion, and alkyl halides

1971 ◽  
Vol 4 (12) ◽  
pp. 400-406 ◽  
Author(s):  
John F. Garst
Keyword(s):  
Electron Transfer ◽  
Radical Anion ◽  
Alkyl Halides

Evidence for single electron transfer in the reaction of alkoxides with alkyl halides

1984 ◽  
Vol 25 (45) ◽  
pp. 5107-5110 ◽  
Author(s):  
E.C. Ashby ◽  
Dong-Hak Bae ◽  
Won-Suh Park ◽  
Robert N. Depriest ◽  
Wei-Yang Su
Keyword(s):  
Electron Transfer ◽  
Alkyl Halides ◽  
Single Electron ◽  
Single Electron Transfer

Concerted double proton-transfer electron-transfer between catechol and superoxide radical anion

2017 ◽  
Vol 19 (38) ◽  
pp. 26179-26190 ◽  
Author(s):  
Jorge Quintero-Saumeth ◽  
David A. Rincón ◽  
Markus Doerr ◽  
Martha C. Daza
Keyword(s):  
Electron Transfer ◽  
Proton Transfer ◽  
Superoxide Anion ◽  
Radical Anion ◽  
Reaction Rate ◽  
Superoxide Radical ◽  
Superoxide Radical Anion ◽  
Double Proton Transfer

Catechol reacts with a superoxide anion via concerted double proton-transfer electron-transfer with a reaction rate that is dominated by tunneling.

Dual electron transfer pathways from the excited C60 radical anion: enhanced reactivities due to the photoexcitation of reaction intermediates

2015 ◽  
Vol 17 (46) ◽  
pp. 31030-31038 ◽  
Author(s):  
Mamoru Fujitsuka ◽  
Tatsuya Ohsaka ◽  
Tetsuro Majima
Keyword(s):  
Electron Transfer ◽  
Radical Anion ◽  
Reaction Intermediates ◽  
Electron Transfer Pathways

The excited C60 radical anion showed enhanced electron transfer.

Radical ions in photochemistry. 21. The photosensitized (electron transfer) tautomerization of alkenes; the phenyl alkene system

1989 ◽  
Vol 67 (4) ◽  
pp. 689-698 ◽  
Author(s):  
Donald R. Arnold ◽  
Shelley A. Mines
Keyword(s):  
Hydrogen Bond ◽  
Electron Transfer ◽  
Radical Cation ◽  
Radical Anion ◽  
Phenyl Group ◽  
Oxidation Potential ◽  
Original Position ◽  
Acetonitrile Solution ◽  
Steric Interaction ◽  
Ambident Anion

Alkenes, conjugated with a phenyl group, can be converted to nonconjugated tautomers by sensitized (electron transfer) irradiation. For example, irradiation of an acetonitrile solution of the conjugated alkene 1-phenylpropene, the electron accepting photosensitizer 1,4-dicyanobenzene, the cosensitizer biphenyl, and the base 2,4,6-trimethylpyridine gave the nonconjugated tautomer 3-phenylpropene in good yield. Similarly, 2-methyl-1-phenylpropene gave 2-methyl-3-phenylpropene, and 1-phenyl-1-butene gaveE- and Z-1-phenyl-2-butene. The reaction also works well with cyclic alkenes. For example, 1-phenylcyclohexene gave 3-phenylcyclohexene, and 1-(phenylmethylene)cyclohexane gave 1-(phenylmethyl)cyclohexene. The proposed mechanism involves the initial formation of the alkene radical cation and the sensitizer radical anion, induced by irradiation of the sensitizer and mediated by the cosensitizer. Deprotonation of the radical cation assisted by the base gives the ambident radical, which is then reduced to the anion by the sensitizer radical anion. Protonation of the ambident anion at the benzylic position completes the sequence. Reprotonation at the original position is an energy wasting step. Tautomerization is driven toward the isomer with the higher oxidation potential, which is, in the cases studied, the less thermodynamically stable isomer. The regioselectivity of the deprotonation step is dependent upon the conformation of the allylic carbon–hydrogen bond. The tautomerization of 2-methyl- 1-phenylbutene gave both 2-phenylmethyl-1-butène and 2-methyl-1-phenyl-2-butene (E and Z isomers), while 2,3-dimethyl- 1-phenylbutene gave only 3-methyl-2-phenylmethyl-1 -butene. In the latter case, steric interaction of the methyls on the isopropyl group prevents effective overlap of the tertiary carbon–hydrogen bond with the singly occupied molecular orbital, thus inhibiting deprotonation from this site. Keywords: photosensitized, electron transfer, alkene, tautomerization, radical cation.

Elektronentransfer und Ionenpaare, 15 [ 1– 3] Radikalanion und Radikal-Kontakt-Ionenpaare von Dimesityl-tetraketon / Electron Transfer and Ion Pairing, 15 [1-3] Radical Anion and Radical Ion Pairs of Dimesityl Tetraketone

1990 ◽  
Vol 45 (8) ◽  
pp. 1197-1204 ◽  
Author(s):  
H. Bock ◽  
P. Hänel ◽  
H.-F. Herrmann
Keyword(s):  
Electron Transfer ◽  
Radical Anion ◽  
Ion Pairs ◽  
Ion Pairing ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Temperature Dependent ◽  
Contact Ion Pairs

The radical anion of dimesityltetraketone (ERed, I = -0.40 V) is easily generated in THF by potassium mirror/[2.2.2]-cryptand reduction. Its contact ion pairs with Na⊕, Cs⊕ and Ba⊕⊕ counter cations, prepared in THF solution by single electron transfer from the respective metals, are characterized by their ESR/ENDOR spectra, which exhibit temperature-dependent metal couplings of aNa⊕ = 0.061 mT (190 K), aCs⊕ = 0.021 mT (190 K), and aBa⊕⊕ = 0.145 mT (295 K).

scholarly journals Ni/Co-Catalyzed Homo-Coupling of Alkyl Tosylates

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1458 ◽  
Author(s):  
Kimihiro Komeyama ◽  
Ryusuke Tsunemitsu ◽  
Takuya Michiyuki ◽  
Hiroto Yoshida ◽  
Itaru Osaka
Keyword(s):  
Electron Transfer ◽  
Oxidative Addition ◽  
Alkyl Halides ◽  
Cobalt Catalysts ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Mild Conditions

A direct reductive homo-coupling of alkyl tosylates has been developed by employing a combination of nickel and nucleophilic cobalt catalysts. A single-electron-transfer-type oxidative addition is a pivotal process in the well-established nickel-catalyzed coupling of alkyl halides. However, the method cannot be applied to the homo-coupling of ubiquitous alkyl tosylates due to the high-lying σ*(C–O) orbital of the tosylates. This paper describes a Ni/Co-catalyzed protocol for the activation of alkyl tosylates on the construction of alkyl dimers under mild conditions.

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