Stereoselectivity in the Fe(II)/Cu(II)-mediated Homolytic Decomposition of thecis- andtrans-Isomers of Pinane Hydroperoxide

2002 ◽  
Vol 31 (8) ◽  
pp. 830-831 ◽  
Author(s):  
H. E. B. Lempers ◽  
R. A. Sheldon ◽  
K. A. D. Swift

1989 ◽  
Vol 93 (10) ◽  
pp. 4029-4033 ◽  
Author(s):  
K. R. Brower ◽  
Jimmie C. Oxley ◽  
Mohan Tewari


Lipids ◽  
1974 ◽  
Vol 9 (9) ◽  
pp. 696-706 ◽  
Author(s):  
H. W. Gardner ◽  
R. Kleiman ◽  
D. Weisleder


1972 ◽  
Vol 50 (8) ◽  
pp. 1167-1180 ◽  
Author(s):  
O. E. Edwards ◽  
D. Vocelle ◽  
J. W. ApSimon

Reactions of N-chloroazacyclooctane and N-chloroazacyclononane are described which give good yields of bicyclic amines. These are: (a) short chain homolytic reactions involving neutral nitrogen radicals initiated by ferrous ion or metallic silver; (b) apparent homogeneous reactions involving silver ion and bases; (c) reactions using silver oxide suspension which also require added bases.Both rate and product composition for (b) and (c) are sensitive to oxygen indicating that they are homolytic processes, probably initiated by traces of silver metal. No evidence for involvement of discrete nitrenium ions was found. However, reaction of N-chloroisoquinuclidine with silver ions has the character of a heterolytic process, giving products completely distinct from those from its homolytic decomposition. The addition of neutral piperidino radicals to styrene is described.



1975 ◽  
Vol 14 (8) ◽  
pp. 568-569 ◽  
Author(s):  
Friedemann Freund ◽  
N. Scheikh-ol-Eslami ◽  
Horst Gentsch


1991 ◽  
Vol 69 (8) ◽  
pp. 1320-1325 ◽  
Author(s):  
X. Lubeigt ◽  
F. Flies ◽  
M. J. Bourgeois ◽  
E. Montaudon ◽  
B. Maillard

Homolytic decomposition induced by addition of dichloromethyl radicals to β- and γ-unsaturated peroxides having a substituent on the chain linking the unsaturation and the peroxide function was studied. The stereochemistry of the heterocycles produced was determined by I3C NMR and the stereoselectivity of intramolecular homolytic substitution on the peroxidic bond discussed. Key words: unsaturated peroxides, homolytic intramolecular substitutions, radical additions, oxygenated heterocycles.





2009 ◽  
Vol 87 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Alicja Haras ◽  
Tom Ziegler

Herein, we report density functional calculations on the epoxidation of cyclohexene with H2O2 activated by (Me2EBC)MnCl2 (Me2EBC stands for 4,11-dimethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane). The computed energy landscapes for different interaction modes of cyclohexene with the MnIV-hydroperoxo complex and the MnV-oxo species support recent experimental findings by Busch and co-workers [J. Am. Chem. Soc. 127, 17170 (2005)], according to which the MnIV-hydroperoxo species is the active complex for olefin epoxidation. Thus, the dominant olefin epoxidation pathway is via direct transfer of the distal protonated oxygen of the hydroperoxo adduct without changes in the oxydation state of its tetravalent metal centre, i.e., the mechanism commonly observed in the uncatalyzed epoxidation by peracids. The homolytic decomposition of the O–OH bond in the active manganese complex leading to the MnV-oxo species is found to be the only epoxidation pathway that could possibly compete with the Oβ transfer from the hydroperoxo adduct. However, the generated MnV-oxo is shown to be a rather poor oxidant resulting in low yields of the target epoxy cyclohexane.Key words: epoxidation, density functional theory, permanganic acid, peracid.



1991 ◽  
Vol 27 (3) ◽  
pp. 255-261 ◽  
Author(s):  
A. K. Yatsimirskii ◽  
I. Ya. Levitin ◽  
O. I. Kavetskaya ◽  
M. V. Tsikalova ◽  
V. I. Bakhmutov ◽  
...  


Sign in / Sign up

Export Citation Format

Share Document