Direct reduction of carboxylic acids into 1,3-dithiolanes with 1,3,2-Di-thiaborolane-dimethyl sulfide complex

Abstract

1,3,2-Dithiaborolane-dimethyl sulfide complex in THF reduces carboxylic acids into the corresponding 1,3-dithiolanes in the presence of Lewis acids without attacking ester, nitro, halide(aliphatic and aromatic), and tosylate. Furthermore, it is possible to reduce carboxylic acids selectively in the presence of t-amide and double bond by use of appropriate Lewis acids. Other carbonyl compounds, ketone, aldehydes, and acid chloride are reacted with the reagent to produce alcohol, alcohol-1,3-dithiolane, and thioester. Of special synthetic significance is the direct conversion of carboxylic acids into 1,3-dithiolanes by one-step sequence.