Reactivity of alkanols and aryl alcohols towards tetrachloroaurate(III) insodium acetate-acetic acid buffer medium

The oxidative behaviour and relative reactivities of three alkanols and 11 aryl alcohols towards gold(III) in sodium acetate-acetic acid buffer were s tudied. The reactions are first order with respect to [Au(III)] and in each [(RRCHOH)-R-1-C-2]. Both H+ and Cl- ions retard the rate of reactions. The reactions obey the following rate expression: [GRAPHICS] AuCl4-, AuCl3(OH2) and AuCl3(OH)(-) are the reactive species of gold(III) a nd the reactivity follows the order AuCl3(OH)(-) > AuCl3(OH2) > AuCl4-. The activation parameters of the reactions were calculated. Alkanols react wit h gold(III) in the order ethanol > methanol > 2-propanol. The unsubstituted benzyl alcohol reacts with gold(III) at a faster rate than benzhydrol. The pseudo-first-order rate constants in the oxidations of aryl alcohols follo w the order NO2 > H > Cl > OMe. The reactions occur via C-H bond cleavage a nd through the intermediate formation of free radicals. Copyright (C) 2001 John Wiley & Sons, Ltd.