Diphenylalanine
Diphenylalanine is a term that has recently been used to describe the unnatural amino acid similar to the two amino acids alanine and phenylalanine. It has been used for the synthesis of pseudopeptide analogues which are capable of inhibiting certain enzymes.
A possible synthesis starts from 3,3-diphenyl-propionic acid which is stereoselective aminated to the diphenylalanine.
A historical use of the term "diphenylalanine" refers to the dipeptide of phenylalanine.