Synthesis of 1,5-Benzothiazepine Dipeptide Mimetics via Two CuI-Catalyzed Cross Coupling Reactions

CuI-catalyzed coupling of 4-methylphenyl bromide with amino acids gives N-aryl amino acids, which are converted into linear dipeptides via iodination and condensation with L-Cysteine derived acyl chloride. Cyclization is achieved via a CuI/N,N-dimethylglycine catalyzed intramolecular coupling of aryl iodides with the liberated thiol to afford 1,5-benzothiazepine dipeptide mimetics.