10.1039/d0ob01149e
The study presents a novel nucleophilic methylthiolation methodology that enables the incorporation of the CH3S- group into activated carbons through either conjugate additions or substitutions reactions. The researchers utilized a range of chemicals, including chalcones, acyl ester derivatives, Morita-Baylis-Hillman acetates, and methylthiomethyl esters as the primary substrates and reagents. Methanethiol, traditionally used for methylthiolation, was replaced with these novel reagents due to its flammability and toxicity. The study aimed to develop a safer, low-cost, transition-metal-free method that exhibits good group tolerance and yields moderate to excellent results. Key chemicals involved in the reaction mechanism include potassium trichloroacetate, acetic acid, and camphorsulfonic acid (CSA) as an organocatalyst. The reaction products were further utilized to synthesize sulfoxides and sulfones, demonstrating the synthetic utility of the methodology. The study also involved theoretical calculations using Density Functional Theory to investigate the reaction mechanism, confirming the role of sulfurane and sulfonium ylide as key intermediates and the importance of a Pummerer rearrangement in the formation of the reagent.
10.1021/ol102567h
The research describes a novel method for the asymmetric synthesis of tertiary benzylic alcohols, which are important functional groups in organic synthesis. The study focuses on the addition of vinyl, aryl, and alkynyl organometallics to ketones containing a stereogenic sulfoxide, resulting in the generation of tertiary alcohols in both diastereomerically and enantiomerically pure forms. The purpose of this research was to develop a high-yielding, selective, and general approach to synthesize these alcohols, which are prevalent in natural products and pharmaceuticals. The researchers utilized toluene sulfonyl groups as chiral auxiliaries and demonstrated that the methodology could be applied to a wide range of substrates, including alkyl-, aryl-, and silyl-substituted alkynes, as well as electron-rich, -poor, and -neutral aryl Grignards. The sulfoxide chiral auxiliary was found to be effective in controlling the asymmetric addition and could be reductively removed to yield the desired tertiary alcohols in high enantiomeric excess. The study concluded that this approach represents a valuable addition to synthetic chemistry, as it provides a way to synthesize optically active tertiary alcohols and convert the chiral auxiliary into other useful functional groups.
