β-Silyl alkynoates: Versatile reagents for biocompatible and selective amide bond formation.

The study introduces a previously unidentified method for amide bond formation that addresses several limitations of conventional approaches. It uses the β-silyl alkynoate molecule, where the alkynyl group activates the ester for efficient amide formation, while the bulky TIPS (triisopropylsilane) group prevents unwanted 1,4-addition reactions. This approach exhibits high chemoselectivity for amines, making the method compatible with a wide range of substrates, including secondary amines, and targets the specific ε-amino group of lysine among the native amino ester's derivatives. It maintains stereochemistry during amide bond formation and TIPS group removal, allowing a versatile platform for postsynthesis modifications such as click reactions and peptide-drug conjugations. These advancements hold substantial promise for pharmaceutical development and peptide engineering, opening avenues for research applications.