761-34-2

Photodriven oxidations of alkanes in trifluoroacetic acid using commercial and synthesized Fe(III) sources as catalyst precursors and dioxygen (O2) as the terminal oxidant are reported. The reactions produce alkyl esters and occur at ambient temperature in the presence of air, and catalytic turnover is observed for the oxidation of methane in a pure O2 atmosphere. Under optimized conditions, approximately 17% conversion of methane to methyl trifluoroacetate at more than 50% selectivity is observed. It is demonstrated that methyl trifluoroacetate is stable under catalytic conditions, and thus overoxidized products are not formed through secondary oxidation of methyl trifluoroacetate.

The role of ruthenium catalysts for the oxidation of alkanes with peracetic acid in trifluoroacetic acid has been confirmed.

Oxidation of cyclohexane in TFA using 30% aqueous H2O2 or urea-H2O2 (UHP) gives cyclohexyl trifluoroacetate in good yield, although the reaction is not accelerated by rhodium or ruthenium catalysts casting doubt

Keywords: Alkane; Dioxirane; Hydroxylierungen; Oxidationen

A simple and efficient method for trifluoroacetoxylation of alkenes using catalytic amounts of V2O5 in trifluoroacetic acid to give the Markovnikov's product selectively in excellent yields for the first time is described.

Alkanes, when treated with lead tetraacetate under thermal or photochemical conditions, undergo a slow but highly selective oxidation to form secondary acetates.

Alkenes undergo a rapid reaction with trifluoroacetic acid containing 0.25 M trifluoroacetic anhydride in the presence of a strong acid catalyst.The enthalpies of trifluoroacetolysis of the five n-hexenes were determined and were corrected to the enthalpies corresponding to the formation of the equilibrium mixture of 2-hexyl trifluoroacetate and 3-hexyl trifluoroacetate.The enthalpy difference between the latter was determined by measuring the equilibrium constant as a function of temperature.The trifluoroacetolysis data may be combined with the measured enthalpies of formation of the alkenes to derive more precise values for the latter.The enthalpies of reaction of water, 2-hexanol, and 3-hexanol with the reaction solvent were determined, and when combined with the other data lead to enthalpies of hydration of the alkenes and the enthalpies of formation of the alcohols.