The Intermediacy of Free Aryl Radicals in the Reaction of o-Alkenyloxybenzenediazonium Salts With Ferrocene

1992 ◽  
Vol 45 (5) ◽  
pp. 857 ◽  
Author(s):  
ALJ Beckwith ◽  
RA Jackson ◽  
RW Longmore

The formation of 3-ferrocenylmethyl-2,3-dihydrobenzofuran (5a) and similar products bearing cyclized substituents, when ferrocene or mixtures of ferrocene and ferrocenium ion are treated witho - allyloxybenzene - or o-but-3-enyloxybenzene-dimonium salts, provides unequivocal evidence for the intermediacy of free aryl radicals in the reaction of ferrocene with arenediazonium salts. The results are consistent with a mechanism involving electron transfer and dediazoniation followed by homolytic attack on ferroce nium ion.

Author(s):  
Mohan Mahesh ◽  
John A Murphy ◽  
Franck LeStrat ◽  
Hans Peter Wessel

Tetrakis(dimethylamino)ethylene (TDAE 1), has been exploited for the first time as a mild reagent for the reduction of arenediazonium salts to aryl radical intermediates through a single electron transfer (SET) pathway. Cyclization of the aryl radicals produced in this way led, in appropriate substrates, to syntheses of indolines and indoles. Cascade radical cyclizations of aryl radicals derived from arenediazonium salts are also reported. The relative ease of removal of the oxidized by-products of TDAE from the reaction mixture makes the methodology synthetically attractive.


2020 ◽  
Vol 11 (27) ◽  
pp. 6996-7002
Author(s):  
Kangjiang Liang ◽  
Qian Liu ◽  
Lei Shen ◽  
Xipan Li ◽  
Delian Wei ◽  
...  

The phenolate anion was developed as a new photocatalyst with strong reduction potentials (−3.16 V vs. SCE) to reduction of aryl halides to aryl radicals through single electron transfer.


2018 ◽  
Vol 42 (9) ◽  
pp. 481-485
Author(s):  
Xiulian Zhang ◽  
Zhicheng Zhang ◽  
Yongbin Xie ◽  
Yujie Jiang ◽  
Ruibo Xu ◽  
...  

A simple and efficient access to arylboronates was achieved with methanol-initiated borylation of aryldiazonium salts. Reduction of aryldiazonium ions by single electron transfer from methanol affords aryl radical species, which undergo a subsequent C–B bond formation with bis(pinacolato)diboron. This highly practical borylation process, which can be carried out on the gram-scale, enjoys operational simplicity as well as mild and catalyst-free conditions.


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