MYTsA, Coupling Reagent

Ynamide, MYTsA is a bench-stable reagent that activates carboxylic acids via α-acyloxyenamide formation, enabling rapid, high-yield amide and peptide bond formation. MYTsA couples free carboxyl and amino groups without racemization/epimerization, even in the presence of common protecting groups and diverse side-chain functionalities such as −OH, −SH, −CONH₂, and the NH of indole. The reaction accelerates in polar solvents, with water serving as an eco-friendly cosolvent. MYTsA facilitates peptide cyclization, esterification, macrolactonization, thioamide/thioester formation, and inverse peptide synthesis via a transient protection strategy, while promoting the multicomponent assembly of β-amino amides from aldehydes, anilines, and carboxylic acids.