Copper-catalyzed three-component reaction to construct thietane ring using elemental sulfur

Thietanes are vital aliphatic four-membered rings associated with various pharmaceuticals, building blocks and synthons of intermediates used in the total synthesis of natural products and biomolecules. Also, 4-thiazolidinone is a core pharmacophore of many drug molecules. Based on their various applications in medicinal chemistry and organic synthesis, an effort has been made to achieve a thietane ring on 4-thiazolidinone nucleus via quasi-benzylic acid-type intramolecular rearrangement using elemental sulfur, benzyl bromide and Cu(I). The designed methodology is environmentally benign, cheap, and easily accessible, with a broad range of substrate scopes and carried out by the employment of earth-abundant metal catalysts like copper.