Kinetic Study of the Radical Azidation with Sulfonyl Azides

2013 ◽  
Vol 66 (3) ◽  
pp. 341 ◽  
Author(s):  
Karin Weidner ◽  
Philippe Renaud
Keyword(s):  
Hydrogen Atom ◽  
Kinetic Study ◽  
Rate Constants ◽  
Alkyl Radical ◽  
Hydrogen Atom Transfer ◽  
Radical Reactions ◽  
Atom Transfer ◽  
Sulfonyl Azides

Rate constants for the reaction between a secondary alkyl radical and two different sulfonyl azides were determined using bimolecular competing radical reactions. The rates of azidation were determined by competition with hydrogen atom transfer from tris(trimethylsilyl)silane ((TMS)3SiH) of the 4-phenylcyclohexyl radical. 3-Pyridinesulfonyl azide and trifluoromethanesulfonyl azide were found to have rate constants for azidation of 2 × 105 M–1 s–1 and 7 × 105 M–1 s–1 at 80°C, respectively.

Experimental Validation of Hydrogen Atom Transfer Gibbs Free Energy as a Predictor of Nitroaromatic Reduction Rate Constants

2019 ◽  
Vol 53 (10) ◽  
pp. 5816-5827 ◽  
Author(s):  
Jimmy Murillo-Gelvez ◽  
Kevin P. Hickey ◽  
Dominic M. Di Toro ◽  
Herbert E. Allen ◽  
Richard F. Carbonaro ◽  
...  
Keyword(s):  
Free Energy ◽  
Hydrogen Atom ◽  
Gibbs Free Energy ◽  
Rate Constants ◽  
Experimental Validation ◽  
Reduction Rate ◽  
Hydrogen Atom Transfer ◽  
Atom Transfer

Hydrogen Atom Transfer Rates from Tp-Containing Metal Hydrides to Trityl Radicals

2020 ◽  
Author(s):  
Hunter B. Vibbert ◽  
Hagen Neugebauer ◽  
Jack R Norton ◽  
Andreas Hansen ◽  
Markus Bursch ◽  
...  
Keyword(s):  
Hydrogen Atom ◽  
Rate Constants ◽  
Transfer Rate ◽  
Metal Hydrides ◽  
Hydrogen Atom Transfer ◽  
Transfer Reactions ◽  
Atom Transfer ◽  
Transfer Rates ◽  
Borate Complexes ◽  
And Tungsten

The H• transfer rate constants for a series of group 6 molybdenum and tungsten pyrazolyl borate complexes are described. The rate constants for these complexes were found to span a range over 1 magnitude. Analysis of the H• transfer rate constants suggests that a combination of steric, electronic, and enthalpic factors are important in these reactions. Further analysis of the components suggests that the generated 17 e– radicals of these complexes are less electrophilic than the more commonly used CpCr(CO)3H complexes. General implications for H• transfer reactions are discussed.

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