Formation of Carbanions from Carboxylate Ions Bearing Electron-Withdrawing Groups via Photoinduced Decarboxylation: Addition of Generated Carbanions to Benzaldehyde

2015 ◽  
Vol 68 (11) ◽  
pp. 1668 ◽  
Author(s):  
Yuta Kumagai ◽  
Takashi Naoe ◽  
Keisuke Nishikawa ◽  
Kazuyuki Osaka ◽  
Toshio Morita ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electron Acceptor ◽  
Radical Anion ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Mild Conditions ◽  
Efficient Generation ◽  
Photochemical Method

The photoinduced decarboxylation of carboxylate ions bearing electron-withdrawing groups using biphenyl and 1,4-dicyanonaphthalene leads to the efficient generation of carbanions under mild conditions. The efficiency of the carbanion generation is strongly dependent on the single-electron transfer from the photogenerated radical anion of the electron-acceptor to the radical. In particular, the cyanomethyl anion formed using this photochemical method can be added to benzaldehydes to give the corresponding adducts.

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.

scholarly journals Iron(III)-Catalyzed Highly Regioselective Halogenation of 8-Amidoquinolines in Water

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 535 ◽  
Author(s):  
Yang Long ◽  
Lei Pan ◽  
Xiangge Zhou
Keyword(s):  
Electron Transfer ◽  
Reaction Mechanism ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Mild Conditions ◽  
Simple Protocol

A simple protocol of iron(III)-catalyzed halogenation of 8-amidoquinolines in water under mild conditions was developed, affording the 5-halogenlated products in good to excellent yields up to 98%. The reaction mechanism most likely involves a single-electron transfer (SET) process.

scholarly journals The special role of B(C6F5)3 in the single electron reduction of quinones by radicals

2018 ◽  
Vol 9 (41) ◽  
pp. 8011-8018 ◽  
Author(s):  
Xin Tao ◽  
Constantin G. Daniliuc ◽  
Robert Knitsch ◽  
Michael Ryan Hansen ◽  
Hellmut Eckert ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Radical Anion ◽  
Single Electron ◽  
Special Role ◽  
Single Electron Transfer ◽  
Electron Reduction ◽  
Trityl Cation

In the presence of two molar equiv. of B(C6F5)3p-benzoquinone reacts with persistent radicals TEMPO, trityl or decamethylferrocene by single electron transfer to give the doubly O-borylated benzosemiquinone radical anion with TEMPO+, trityl cation or ferrocenium counter cations.

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