Absolute rate constants for the Reactions of tert-Butoxyl, tert-Butylperoxyl, and Benzophenone Triplet with Amines: The Importance of a Stereoelectronic Effect

Article abstract of DOI:10.1021/ja00393a020

Absolute rate constants have been determined for the reactions of tert-butoxyl, tert-butylperoxyl, and benzophenone triplet with a variety of amines.All three reagents abstract hydrogen from the carbon α to nitrogen with rate constants which are much greater than those for the corresponding reactions with hydrocarbons and isostructural ethers.This rate enhancement is attributed to polar effects on the transition state and to the stabilization of α-aminoalkyls.These product radicals are stabilized by conjugation between the unpaired electron and the nitrogen lone pair, and, as a result, the hydrogen abstractions show a pronounced stereoelectronic effect with abstraction being most facile when the C-H bond being broken is eclipsed with the axis of the nitrogen lone-pair orbital.