Chemically Triggered C-ON Bond Homolysis in Alkoxyamines. 6. Effect of the Counteranion

Gérard Audran (1) , Paul Brémond (1) , Sylvain R.A. Marque (1) , Germain Obame (1)

1 ICR - Institut de Chimie Radicalaire

We showed (J. Org. Chem. 2012, 77, 9634) that the activation by methylation of pyridyl-based alkoxyamine 1 increased with the hydrogen bond donor properties of solvents. In this paper, activation of 1 by protonation with acids, CF3COOH and CSA, in tert-butylbenzene (t-BuPh) and in H2O/MeOH afforded, with CF3COOH, k(d) 28-fold larger in H2O/MeOH than in t-BuPh, whereas it was only 4-fold larger when CSA was used. This puzzling observation was ascribed to the dissociation of the intimate ion pair.

Domaines: Chimie

Gérard Audran, Paul Brémond, Sylvain R.A. Marque, Germain Obame. Chemically Triggered C-ON Bond Homolysis in Alkoxyamines. 6. Effect of the Counteranion. Journal of Organic Chemistry, 2013, 78 (15), pp.7754--7757. ⟨10.1021/jo401227a⟩. ⟨hal-01460444⟩