Copper‐Catalyzed Decarboxylative Synthesis of α‐Ketothioamides Using α,β‐Unsaturated Arylcarboxylic Acids, Alicyclic Secondary Amines and Elemental Sulfur

Metal-free oxidative coupling of aryl acetylene with elemental sulphur and amines: facile access to α-ketothioamides

A simple and efficient oxidative coupling of aromatic alkynes with elemental sulphur and secondary amines has been reported. The iodine/DMSO system easily promoted the transformations, affording thioglyoxamides via C-S, C-O, and C-N bond formations. In this context, acetylenic C-H bond oxidation has occurred through iodination, leading to the desired products. Moreover, this metal-free, one-pot protocol is accomplished by using readily available starting materials, without external oxidants, and under aerobic conditions, providing a variety of α-ketothioamide compounds in moderate to good yields.

Nucleophilic sulfur controlled efficient ketothioamide synthesis from tribromomethyl carbinols

A mild, catalyst and oxidant-free efficient protocol for synthesizing α-ketothioamides is reported with a broad substrate scope. The presented protocol demonstrates the confined reactivity of amines. The polysulfide derived from elemental sulfur and amines in an aqueous medium drives the pathway toward diverse α-ketothioamides over thioamides. Substrates with different substituent groups were compatible with the presented protocol, and the respective ketothioamides were separated in good to excellent yields. The ketothioamides, known to exhibit anti-cancer properties, were synthesized by the proposed protocol. Furthermore, the synthetic utility was explored with the typical synthesis of ketoamides.

Towards More Practical Methods for the Chemical Synthesis of Thioamides Using Sulfuration Agents: A Decade Update

Compounds possessing a thioamide function play a crucial role in organic synthesis, serving as key building blocks. They are also important in the pharmaceutical chemistry and drug design, owing to their ability to mimic the amide function in biomolecules while retaining or developing biological activity. From the synthetic viewpoint, several methods have been developed for preparing thioamides using sulfuration agents. The purpose of this review is to give an update of the last decade of contributions focusing on the formation of thioamides employing different sulfur sources. When appropriate, the cleanness and practicality of the new methods are highlighted.