Simple and Highly Efficient Synthesis of Thioamide Derivatives Using β‐Cyclodextrin as Supramolecular Catalyst in Water

A simple, straightforward and highly efficient approach for the synthesis of thioamide derivatives in water at 100 oC has been developed. Total 22 compounds were prepared via a one‐pot multicomponent reaction between substituted aldehydes, sulfur powder and secondary amines by using recyclable catalyst β‐cyclodextrin indicating the broad substrate scope of this method. The salient features of the present protocol are water as a green solvent, non‐toxic catalyst, good to excellent yields of products, operational simplicity, eco‐friendliness and easy isolation of products. The used catalyst was recovered and reused several times without significant loss of catalytic activity, which is an essential parameter of green synthesis. We explore here synthetic utility of β‐cyclodextrin as a supramolecular, non‐toxic, biodegradable and efficient catalyst for sythesis thioamide via a one‐pot multicomponent reaction between substituted aldehydes, sulfur powder and secondary amines. Metal and oxidant free protocol was investigated with short reaction time 30–90 min. Total 22 compounds were prepared. The catalyst was recovered and reused several times without significant loss of catalytic activity and use of water as a green solvent which is an essential parameter of green chemistry.