N-Heteroarylation of chiral α-aminoesters by means of palladium-catalyzed Buchwald-Hartwig reaction.

ABSTRACT

N-Heteroaryl-α-amino acid derivatives are valuable pharmacological agents as peptidomimetics. Classical SNAr methods using acid catalysis and elevated temperatures could not be extended to various α-amino acids and fairly electrophilic heterocyclic partners. Here, we report a mild and versatile method of N-heteroarylation of chiral α-aminoesters without racemization, involving Buchwald-Hartwig conditions. It could be extended to various α-amino acids and azines. This efficient N-heteroarylation leads to (i) a chemical library of putative peptidomimetics combining diverse azaheterocycles with the chiral α-aminoesters and their corresponding derivatives (amides, alcohols, etc.) and (ii) arginine derivatives designed as NPFF receptor ligands.