Peptides and proteins are essential components for sustaining life. Synthetic methods for their production are needed to enable investigations into their structure and function. Typically, peptides are made synthetically using solid-phase peptide synthesis (SPPS) up to approximately 50 amino acids. These fragments are then used to access longer peptides and proteins through selective coupling know as native chemical ligation (NCL). NCL achieves this site and termini selectivity using the reaction of a C-terminal thioester and N-terminal thiol. However, the commonly used method leaves a Cysteine (Cys) residue at each juncture, which is the least abundant amino acid naturally. Our research aims to explore the synthesis of synthetic amino acids that enable NCL to produce a new peptide bond at a range amino acid junction through the elimination of a thiol auxiliary. Creating these amino acids would allow access to a wider range of natural peptides and proteins.