A Convenient Method for the Stereoselective Conversion of Aryl Peptidyl Ketones into the Corresponding Aryl Aminomethin Derivatives, A Novel Class of Modified Peptides

In this paper we describe a reductive amination procedure that can be employed in the preparation of a novel class of pseudopeptides in which a specific amide bond is replaced by a CH(Ar)NH group. The developed methodology, performed using NaBH3CN and TiCl4, is characterized by the formation of diastereomeric intermediates in a relative 1:1 ratio. It provides aryl aminomethin pseudopeptides in moderate but satisfactory yields and with definite stereochemistry on the asymmetric centres next to the modified peptide bond.