Epimerization- and protecting-group-free synthesis of peptidomimetic conjugates from amphoteric amino aldehydes

We have developed a novel protecting-group-free strategy for the synthesis of peptidomimetic conjugates. The high degrees of stereocontrol and chemoselectivity achieved in this chemistry hinge upon unusual preferences of the amphoteric amino aldehydes. The resulting conjugates contain reduced amide bonds at defined positions, offering a possibility for peptidomimetic ligation. These findings should allow access to templates for introducing both natural and unnatural amino acid residues in close proximity to the reduced amide bond isosteres.