Synthesis of S-alkyl thiobenzoates from alkyl halides mediated by poly(4-vinylpyridine) supported sodium thiobenzoate at room temperature under heterogeneous conditions

One-pot synthesis of thioesters with sodium thiosulfate as a sulfur surrogate under transition metal-free conditions

In this paper, we report an efficient synthetic method for thioester formation from sodium thiosulfate pentahydrate, organic halides, and aryl anhydrides. In the one-pot two-step reactions developed in this study, sodium thiosulfate was used as the sulfur surrogate for acylation with anhydrides, followed by substitution with organic halides through the in situ generation of thioaroylate. Furthermore, two important organic compounds could be successfully synthesized using our developed method. The advantages of the one-pot two-step reactions are operational simplicity, structurally diverse products with 42%-90% yields, use of relatively low toxic and odourless reagents, and easy applicability to large-scale operation.

Microwave-Assisted Direct Thioesterification of Carboxylic Acids

A one-pot synthesis of thioesters directly from carboxylic acids, N,N'-diphenylthiourea, triethylamine, and primary alkyl halides is described. Microwave-assisted heating and a catalytic amount of 4-(dimethylamino)pyridine (DMAP) further improved the yields. Both aromatic and aliphatic carboxylic acids were converted to the corresponding thioesters, and many functional groups were compatible with this reaction. Several possible reaction intermediates were investigated, and the quaternary ammonium salts, derived from alkyl halides and tertiary amines, were the intermediates to yield thioesters. A new reaction mechanism for this thioesterification is proposed.