Catalyst-free radical fluorination of sulfonyl hydrazides in water

2016 ◽  
Vol 18 (5) ◽  
pp. 1224-1228 ◽  
Author(s):  
Lin Tang ◽  
Yu Yang ◽  
Lixian Wen ◽  
Xingkun Yang ◽  
Zhiyong Wang
Keyword(s):  
Free Radical ◽  
Radical Process ◽  
Catalyst Free ◽  
Free Radical Process

The first catalyst-free fluorination of sulfonyl hydrazides for the synthesis of sulfonyl fluorides via a free-radical process has been developed.

Absolute rate constants for hydrocarbon autoxidation. 32. On the self-reaction of 1,1-diphenylethylperoxyl in solution

1982 ◽  
Vol 60 (20) ◽  
pp. 2566-2572 ◽  
Author(s):  
J. A. Howard ◽  
J. H. B. Chenier ◽  
T. Yamada
Keyword(s):  
Free Radical ◽  
Rate Constants ◽  
The Self ◽  
Absolute Rate ◽  
Radical Process ◽  
First Order ◽  
Hydroperoxide Decomposition ◽  
Solvent Cage ◽  
Induced Decomposition ◽  
Free Radical Process

The major products of the self-reaction of 1,1-diphenylethylperoxyl have been determined from product studies of the autoxidation of 1,1-diphenylethane, induced decomposition of 1,1-diphenylethyl hydroperoxide, and decomposition of 2,2,3,3-tetraphenylbutane under an atmosphere of oxygen. Overall self-reaction is a complex free-radical process involving the intermediacy of 1,1-diphenylethoxyl and 1-phenyl-1-phenoxyethoxyl which undergo H-atom abstraction, β-scission and, in the case of the former radical, rearrangement. Hydroperoxide decomposition under an atmosphere of 36O2 has shown that 1,1-diphenylethylperoxyl undergoes β-scission faster than α-cumylperoxyl at 303 K in solution. The values of the rate constants for self-reaction of Ph2C(Me)O2• relative to those for tert-butylperoxyl are, however, not affected by this reaction. Furthermore they are not affected to any appreciable extent by the efficiency with which Ph2C(Me)O•, formed in nonterminating self-reactions, escape from the solvent cage. They are influenced principally by the first-order rate of decomposition of Ph2C(Me)OOOOC(Me)Ph2.

Hydrogels based on pullulan derivatives crosslinked via a “living” free-radical process

2002 ◽  
Vol 203 (10-11) ◽  
pp. 1285-1291 ◽  
Author(s):  
Vittorio Crescenzi ◽  
Mariella Dentini ◽  
Debora Bontempo ◽  
Giancarlo Masci
Keyword(s):  
Free Radical ◽  
Radical Process ◽  
Free Radical Process

Oxidative addition to iridium(I). Free-radical process

1972 ◽  
Vol 94 (11) ◽  
pp. 4043-4044 ◽  
Author(s):  
John S. Bradley ◽  
Dan E. Connor ◽  
David Dolphin ◽  
Jay A. Labinger ◽  
John A. Osborn
Keyword(s):  
Free Radical ◽  
Oxidative Addition ◽  
Radical Process ◽  
Free Radical Process

A Theoretical Study of the Stevens Rearrangement of Methylammonium Methylide and Methylammonium Formylmethylide

1993 ◽  
Vol 46 (9) ◽  
pp. 1375 ◽  
Author(s):  
GL Heard ◽  
KE Frankcombe ◽  
BF Yates
Keyword(s):  
Free Radical ◽  
Theoretical Study ◽  
Energy Difference ◽  
Reaction Pathways ◽  
Molecular Orbital Theory ◽  
Orbital Theory ◽  
Radical Process ◽  
Stevens Rearrangement ◽  
Semi Empirical ◽  
Free Radical Process

Ab initio and semi-empirical molecular orbital theory has been used to study the reaction pathways of the Stevens rearrangement of the prototype methylammonium methylide and methylammonium formylmethylide . For both reactions, the stepwise (free radical) process is predicted to require less energy than the concerted rearrangement (in accordance with experimental suggestions). With inclusion of electron correlation, the energy difference between these pathways is reduced; however, for the smaller system at the CCSD/6-31G(d) level of theory, the free radical process is still favoured by over 180 kJ mol-1. For both systems, the concerted transition structures for the pericyclic mechanisms reveal that some amount of bonding is retained in these formally symmetry-forbidden processes.

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