Recent progress in the construction of thioamide using inorganic sulfur

This review highlights innovative strategies for green synthesis of biologically crucial thioamides and peptides using inorganic sulfur. Addressing traditional challenges in regioselectivity and stereochemical control, our methodologies employ CuCl₂-catalyzed ligation, trichlorosilane-mediated coupling, and multicomponent reactions with elemental sulfur. These approaches achieve high atom economy, broad functional tolerance (Met, Tyr, Trp derivatives), and pharmaceutical applicability. Key breakthroughs include stereoretentive carbonyl-selective sulfurization in peptides and efficient thioamide installation via silane migration pathways. The sustainable methods enable complex peptide synthesis while overcoming limitations of conventional thioamidation reagents.