In recent years a range of novel amide ligation strategies have been developed, many incorporating sulfur-containing reagents as thioesters and other carboxylic acid surrogates. We recently reported a novel method for peptide synthesis based on the reaction of thioamides with carboxylic acids in the presence of Ag(I).1,2 These reactions proceed via Ag(I)-promoted activation of the thioamide leading to formation of an isoimide intermediate, which can undergo acyl transfer processes to generate a variety of adducts. Recent progress in this area will be highlighted, including novel strategies for macrocyclization and ligation of peptide thioamides.3,4