Superfast and Water‐Insensitive Polymerization on α‐Amino Acid N‐Carboxyanhydrides to Prepare Polypeptides Using Tetraalkylammonium Carboxylate as the Initiator

We design the tetraalkylammonium carboxylate-initiated superfast polymerization on α-amino acid N-carboxyanhydrides (NCA) for efficient synthesis of polypeptides. Carboxylates, as a new class of initiator for NCA polymerization, can initiate the superfast NCA polymerization without the need of extra catalysts and the polymerization can be operated in open vessels at ambient condition without the use of glove box. Tetraalkylammonium carboxylate-initiated polymerization on NCA easily affords block copolymers with at least 15 blocks. Moreover, this method avoids tedious purification steps and enables direct polymerization on crude NCAs in aqueous environments to prepare polypeptides and one-pot synthesis of polypeptide nanoparticles. These advantages and the mild polymerization condition of tetraalkylammonium carboxylate-initiated NCA polymerization imply its great potential in functional exploration and application of polypeptides.