John R. Peterson

Mechanisms for Manganese(III) Oxidations with Alkenes

Abstract In the reaction of manganese(III) acetate with carboxylic acids and alkenes, three distinct processes have been identified which involve the alkene and two processes which are independent of alkene. A combination of product studies, rearrangements, dilution experiments and literature kinetic data allow the proposal of a unified mechanistic picture to describe these processes. Specifically, the role of α-H acidity of the carboxylic acid component, electron deficient radical additions, metal complexed organic radicals, and the importance of an oxo-centered manganese(III) triangle are discussed as they relate to the lactone annulation reaction. Single electron transfer oxidation of alkenes is described as a route toward 1,2-diacetates of alkenes within the 8.1-7.5 eV I.P. range. Three less common modes of Mn(III) reaction are discussed and compared with the two primary processes of lactone annulation and 1,2-diacetate formation.

Chlorination of alkenes by manganese(III) chloride species

Several manganese(III) chloride species have been prepared in situ and used as effective chlorinating agents of alkenes.

Iron(II) catalyzed persulfate oxidation of alkenes to vicinal diacetates

Abstract Mono- and disubstituted alkenes are converted to trans -vicinal diacetates by heating with an acetic acid solution of ammonium persulfate and a ferrous sulfate catalyst.

Oxidative Coupling of Arylthiols to Diaryl Disulfides

Abstract An exceedingly simple and inexpensive method for oxidatively coupling arylthiols to diaryl disulfides is described. The procedure uses only stoichiometric amounts of the arylthiol and dimethyl sulfoxide at room temperature.

Alkene oxidatioh by an iron(II)/persulfate/acetic acid system

Abstract Mono- and disubstituted alkenes were converted to trans-vicinal diacetates by heating with an iron(II)/persulfate/acetic acid system. The synthetic utility and limitations were identified. A mechanism for the transformation is proposed which involves an initial addition of sulfate radical anion to the alkena followed by solvolysis, addition, hydrolysis, and aoetylation.

γ-Hydroxyacetylenic Acid Derivatives: Generation from Propiolic Acid and Ester Anions and Their Use in Butenolide Synthesis

Abstract γ-Hydroxyacetylenic acids and esters have been found to be conveniently prepared in our laboratory by the addition of the propiolic acid dianion1 or the acetylide of methylpropiolate2 to an aldehyde or to a ketone (Scheme I, Table I). These polyfunctional compounds have been shown previously to be useful synthetic intermediates in route to such compounds as 1,3-dienes,2 carbohydrates3 and butenolides.4–7