Copper-catalyzed oxidative alkenylation of C(sp3)–H bonds via benzyl or alkyl radical addition to β-nitrostyrenes

2015 ◽  
Vol 39 (4) ◽  
pp. 3093-3097 ◽  
Author(s):  
Shengrong Guo ◽  
Yanqin Yuan ◽  
Jiannan Xiang

A new method for the preparation of (E)-β-alkylstyrene derivatives has been developed via the addition of benzyl or alkyl radicals to β-nitrostyrenes using di-tert-butyl peroxide (DTBP) as the oxidant in the presence of Cu powder catalyst.

2019 ◽  
Author(s):  
Tuhin Patra ◽  
Satobhisha Mukherjee ◽  
Jiajia Ma ◽  
Felix Strieth-Kalthoff ◽  
Frank Glorius

<sub>A general strategy to access both aryl and alkyl radicals by photosensitized decarboxylation of the corresponding carboxylic acids esters has been developed. An energy transfer mediated homolysis of unsymmetrical sigma-bonds for a concerted fragmentation/decarboxylation process is involved. As a result, an independent aryl/alkyl radical generation step enables a series of key C-X and C-C bond forming reactions by simply changing the radical trapping agent.</sub>


Synthesis ◽  
2022 ◽  
Author(s):  
Xiaosheng Luo ◽  
Qiping Feng ◽  
Ping Wang

Herein, we report the formation of C(sp3)-centered radicals via the electro-induced homolysis of 4-alkyl-1,4-dihydropyridines (alkyl-DHPs). The resulting alkyl radicals reacted with hydroxy quinazolines or quinones to afford 2-alkyl dihydroquinazolinones or alkylated quinones. A broad range of alkyl DHPs could be used as versatile radical precursors under electrolysis conditions. This alterative strategy provided a simple and effective pathway for the construction of C(sp2)–C(sp3) and C(sp3)–C(sp3) bonds under mild conditions.


2009 ◽  
Vol 50 (12) ◽  
pp. 1301-1302 ◽  
Author(s):  
Tomoko Yajima ◽  
Masako Hamano ◽  
Hajime Nagano

The electron spin resonance method was employed to study the nature, concentration and kinetics of the disappearance under varying conditions of radicals produced in polyethylene by fast electron irradiation at 77°K. The predominant radical species at 77°K is the alkyl radical —CH 2 —ĊH—CH 2 —. On being warmed to room temperature it disappears rapidly, revealing a more stable un­identified radical. The kinetics of the decay at room temperature of both radicals was observed. Their stabilities were found to vary in polyethylene samples of differing physical and chemical properties. G values for these radicals are given. Comparison was made with spectra obtained under similar conditions with two pure paraffins and a pure olefin to evaluate the effect of crystallinity branching, molecular weight and unsaturation. In the olefin there is evidence for a build-up of allyl radicals due to the encounter of an alkyl radical with main chain unsaturation. This supports the view that alkyl radicals are mobile, and cross-linking occurs when two such radicals meet.


2019 ◽  
Vol 6 (17) ◽  
pp. 3065-3070 ◽  
Author(s):  
Yong Peng ◽  
Yuan-Yuan Jiang ◽  
Xue-Jiao Du ◽  
Da-You Ma ◽  
Luo Yang

Decarbonylation of aliphatic aldehydes into 1°, 2° and 3° alkyl radicals to construct C(sp3)–C(sp3) bond via radical addition and C(sp3)–O bond via the interconversion of CoII–CoIII–CoI.


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