An overview of the applications of Nalpha-(1-phenyl-2-mercaptoethyl) auxiliary is presented. We describe the on resin preparation (Calpha-carboxy and thioester) of Nalpha-auxiliary derivatives of glycine and the synthesis and incorporation of preformed Nalpha-auxiliary derivatives of glycine and alanine with the protection schemes, including the thiazolidine strategy for SPPS. Such approaches allowed the synthesis of the protein cytochrome b562 as well as native circular peptides after successful removal of the auxiliary.