Simple and Highly Efficient Synthesis of Thioamide Derivatives Using beta-Cyclodextrin as Supramolecular Catalyst in Water

A simple, straightforward and highly efficient approach for the synthesis of thioamide derivatives in water at 100 degrees C 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 beta-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.