Electron-Transfer-Induced Reductive Cleavage of Phthalans: Reactivity and Synthetic Applications

The behavior of phthalan (1a) was investigated under conditions of electron transfer from alkali metals in aprotic solvents. Reaction with lithium in the presence of a catalytic amount of naphthalene in THF led to the reductive cleavage of an arylmethyl carbon−oxygen bond, with formation of a stable dilithium compound. Trapping of this intermediate with several electrophiles (alkyl halides, carbonyl derivatives, CO2) was successful. The extension of this procedure to several substituted phthalans (1b−i) was investigated, and the regiochemistry as well as the synthetic usefulness of these reactions are discussed

Tuning the Reducing Properties of 1,2-Diaryl-1,2-disodiumethanes

We investigated the reducing properties of a series of 1,2-diaryl-1,2-disodiumethanes by means of equilibration reactions. The electron-donor power of these vic-diorganometals is strongly affected by the nature of substituents present either on the aromatic ring(s) or on the carbanionic centers, and it can be correlated with their ability to delocalize the arylmethyl carbanions. These findings are supported by electrochemical analysis of the reduction behavior of the parent 1,2-diarylalkene. Applications of these results to the reduction of selected substrates are described

BH₃-Promoted Stereoselective β-Lithiation of <i>N</i>-Alkyl-2-phenylaziridines

BH3 complexes of N-alkyl-2-phenylaziridines have been synthesized and their structure and stereochemistry proved with DFT calculations and NMR experiments. It has been demonstrated that the Lewis acid complexation is able to promote a regioselective β-lithiation in 2-phenylaziridino−borane complexes. The lithiated intermediates were configurationally stable, allowing an enantioselective preparation of cis-2,3-disubstituted aziridines

Quantitative 1H NMR analyses of the vegetable oils and GC validation from Aquivion perfluorosulfonic superacid as an effective catalyst for selective epoxidation of vegetable oils

The acid-promoted epoxidation of vegetable oils was studied using a variety acidic ion exchange resins as heterogeneous acid catalysts. Quantitative and selective epoxidation of a series of vegetable oils with different composition of saturated, mono-, di- and tri-unsaturated fatty acids was obtained upon identification of the more efficient catalyst and experimental conditions. Furthermore, optimized reaction conditions were successfully applied to the epoxidation of a waste cooking oil, thus extending our procedure to the valorization of a biowaste, an area of increasing importance within a more sustainable society. The use of quantitative 1H NMR besides making accurate evaluation of the amounts of reagents to be employed and of the selectivity, allowed facile and rapid quantification of mono-, di- and tri-epoxides, thus providing an indirect indication on the fatty acid composition of the vegetable oils, even in the presence of very low quantities of linolenic acid