Synthesis and crystal structure of a tripeptide comprising a centrally placed non-coded aromatic γ-amino acid

A protected tripeptide Boc- l -Leu-5-AIA-Aib-OMe was synthesized where 5 -aminoisophthalic acid (5-AIA), a rigid non-coded aromatic γ-amino acid is incorporated as central residue. The single crystal X-ray diffraction study indicates that the peptide self-assembles into supramolecular sheet through intermolecular hydrogen bonding interaction N–H ⋯ O and π ··· π interaction.