Efficient peptide coupling method of conjugated carboxylic acids with methyl ester amino acids hydrochloride. Application to the synthesis of Fa-Met, an important enzymatic substrate

Benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate reagent (BOP) serves as an efficient and versatile coupling reagent for the coupling of conjugated carboxylic acid with methyl ester amino acids hydrochloride allowing the synthesis of various substituted amino acid derivatives in high chemical yields of up to 90%. The usefulness of this method is illustrated in the synthesis of Fa-Met, an important enzymatic substrate.