Single-Step Thioetherification by Indium-Catalyzed Reductive Coupling of Carboxylic Acids with Thiols

A Green Route to Benzyl Phenyl Sulfide from Thioanisole and Benzyl Alcohol over Dual Functional Ionic Liquids

Benzyl phenyl sulfide is a kind of important chemicals with wide usage, which is mainly prepared through a nucleophilic reaction of thiophenol with benzyl chlorides or benzyl alcohols, suffering from inherent drawbacks, such as low efficiency, requirements for equivalent acid or base catalysts and formation of harmful byproducts and waste. Herein, we report a green route to access various benzyl phenyl sulfide derivatives in good to excellent yields under mild conditions via the reaction of thioanisoles with benzyl alcohols over ionic liquid 1-propylsulfonate-3-methylimidazolium trifluoromethanesulfonate ([SO₃ HPrMIm][OTf]). Mechanism investigation indicates that the synergic effect of cation and anion of [SO₃ HPrMIm][OTf] activates thioanisoles and benzyl alcohols via hydrogen bonding, thus catalyzes the dehydration of benzyl alcohol to dibenzyl ether and the subsequent metathesis reaction between dibenzyl ether and benzyl phenyl sulfide, finally generating benzyl phenyl sulfide derivatives. This is a simple, highly efficient, and green approach to produce benzyl phenyl sulfide derivatives, which has promising application potentials.

Production of Alkyl Aryl Sulfides from Aromatic Disulfides and Alkyl Carboxylates via a Disilathiane-Disulfide Interchange Reaction

The results of this study show that disilathiane is an effective mediator in the synthesis of alkyl aryl sulfides with disulfides and alkyl carboxylates. Mechanistic studies suggest that disilathiane promotes cleavage of the sulfur-sulfur bond of disulfides to generate thiosilane as a key intermediate. Diselenides were also applicable to this transformation to produce the corresponding selenides.

Deoxygenative Functionalizations of Aldehydes, Ketones and Carboxylic Acids

Conversion of carbonyl compounds, including aldehydes, ketones and carboxylic acids, into functionalized alkanes via deoxygenation would be highly desirable from a sustainability perspective and very enabling in chemical synthesis. This review covers the recent methodology development in carbonyl and carboxyl deoxygenative functionalizations, highlighting some typical and significant contributions in this field. These advances will be categorized based on types of bond formation, and in each part, selected examples will be discussed from their generalized mechanistic perspectives. Four summarized reactivity modes of aldehydes and ketones during the deoxygenation, namely, bis-electrophile, carbenoid, bis-nucleophile and alkyl radical, are presented, while the carboxylic acids are deoxygenated mainly via activated carbonyl or acetal intermediates.

Unusual Deoxidative Coupling Reaction of β-Sulfinyl Esters with Benzylic Trimethylammonium Salts

A KOH-promoted unusual deoxidative coupling reaction of β-sulfinyl esters with benzylic trimethylammonium salts to produce thioethers is discovered for the first time. If quaternary ammonium salts synthesized from enantiomerically enriched amines are adopted, highly enantiomerically enriched benzyl thioethers (>95-99% ee) with configurations opposite to those of the enantiomerically enriched amines are obtained.

Gallium-catalyzed reductive lactonization of γ-keto acids with a hydrosilane

Gallium chloride efficiently catalyzes cyclization of γ-keto carboxylic acids in the presence of PhSiH₃ to produce the corresponding γ-lactone derivatives.

Main group catalysed reduction of unsaturated bonds

This Perspective article reviews the recent developments in reduction reactions catalysed by main-group element compounds.