39041-58-2Relevant articles and documents
Absolute Rate Constants for the Addition of Triethylsilyl Radicals to the Carbonyl Group
Chatgilialoglu, C.,Ingold, K. U.,Scaiano, J. C.
, p. 5119 - 5123 (2007/10/02)
The absolute rate constants for the reactions of Et3Si. radicals with a large number of carbonyl-containing compounds have been measured in solution by using laser flash photolysis for compounds having rate constants >105 M-1 s-1 and kinetic EPR spectroscopy for compounds having rate constants 5 M-1 s-1.The reactivities have a wide range, e.g., the rate constants at ca. 300 K are 2.5 * 109, 3.3 * 108, 1.6 * 106, 2.8 * 105, and 3.5 * 104 M-1 s-1 for duroquinone, benzil, propionic anhydride, diethyl ketone, and ethyl formate, respectively.Arrhenius parameters were determined for a few representative substrates.Thus for benzil, Ea = (1.02 +/- 0.09) kcal/mol and log (A/M-1 s-1) = 9.26 +/- 0.07.Polar effects are very important in determining the reactivity of carbonyl-containing compounds toward Et3Si. radicals; e.g., reactivities are greatly enchanced by neighboring perfluoroalkyl and acyloxy groups.
