scholarly journals The reduction of α-bromocamphor by tertiary amines

1992 ◽  
Vol 70 (1) ◽  
pp. 173-176 ◽  
Author(s):  
Jian Jeffrey Chen ◽  
Dennis D. Tanner
Keyword(s):  
Electron Transfer ◽  
Free Radical ◽  
Chain Termination ◽  
Tertiary Amines ◽  
Chain Mechanism ◽  
Chain Reaction ◽  
Radical Chain ◽  
Electron Transfer Chain ◽  
Chain Sequence ◽  
Transfer Chain

The reduction of α-bromocamphor to camphor by N,N-dimethylaniline (DMA) at high temperatures (> 200 °C) proceeds via a free radical chain sequence. The reduction can be effected with DMA or triethylamine (TEA) in acetonitrile at much lower temperatures in the presence of di-tert-butylperoxide. The chain termination step is the dimerization of the camphor radical. These reductions presumably constitute an example of an electron transfer chain mechanism involving a tertiary amine as the chain propagating species. Keywords: reduction, tertiary amines, α-bromocamphor, chain reaction.

scholarly journals Electron transfer chain reaction of the extracellular flavocytochrome cellobiose dehydrogenase from the basidiomycete Phanerochaete chrysosporium

FEBS Journal ◽  
2005 ◽  
Vol 272 (11) ◽  
pp. 2869-2877 ◽  
Author(s):  
Kiyohiko Igarashi ◽  
Makoto Yoshida ◽  
Hirotoshi Matsumura ◽  
Nobuhumi Nakamura ◽  
Hiroyuki Ohno ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Phanerochaete Chrysosporium ◽  
Cellobiose Dehydrogenase ◽  
Chain Reaction ◽  
Electron Transfer Chain ◽  
Transfer Chain

Radiation Reactions of Unsaturated Polyesters

1958 ◽  
Vol 244 (1236) ◽  
pp. 54-71 ◽  
Keyword(s):  
Molecular Weight ◽  
Free Radical ◽  
Chain Termination ◽  
Chain Mechanism ◽  
Radical Chain ◽  
Unsaturated Polyesters ◽  
Addition Chain ◽  
Chain Lengths ◽  
Intensity Radiation ◽  
Time Lead

The polymerization of monomers containing more than one double bond may lead to the formation of crosslinked polymers. The monomers involved in this work were unsaturated polyesters. Ionizing radiation was found to initiate polymerization and, at the same time, lead to an insoluble network by causing crosslinking between the polyester chains. The effect of both low- and high-intensity radiation, additives, oxygen and temperature has been studied and it is shown that the polymerization proceeds via a free-radical chain mechanism, although the poly-addition chain lengths produced seem to be very short. The absence of any dependence of the conversion on the radiation intensity suggests an unusual chain-termination step. An analysis of the results shows that neither the structure of the polyester nor its type of molecular weight distribution is of major importance in affecting the general course of the polymerization.

The course of reaction of 4-nitrobenzyl bromide and 5-nitrofurfuryl bromide with bases: Operation of anion-radical mechanism

1982 ◽  
Vol 47 (5) ◽  
pp. 1334-1338 ◽  
Author(s):  
Josef Prousek
Keyword(s):  
Electron Transfer ◽  
Reaction Mechanism ◽  
Anion Radical ◽  
Radical Mechanism ◽  
Charge Transfer Complexes ◽  
Chain Reaction ◽  
Electron Transfer Chain ◽  
Initial Stage ◽  
Transfer Chain ◽  
Ethylene Derivative

4-Nitrobenzyl bromide (I) - contrary to 5-nitrofurfuryl bromide (V) - does not react with hard bases in an electron-transfer chain reaction, giving instead product of SN2 reaction. However, its reaction with soft bases affords 1,2-bis(4-nitrophenyl)ethane (III) as anion-radical mechanism product. 5-Nitrofurfuryl bromide reacts with hard bases to give 1,2-bis(5-nitro-2-furyl)ethylene (VI) whereas with soft bases 1,2-bis(5-nitro-2-furyl)ethane (VII) is formed. The derivative VII on reaction with ethanolic NaOH reacts by α-E1cB mechanism under formation of the ethylene derivative VI. The derivative III does not react by this mechanism. The solvent and base effects on the formation of charge-transfer complexes in the initial stage of these reactions in relation to the reaction mechanism are discussed.

Sign in / Sign up

Export Citation Format

Share Document