Rh-Catalyzed Hydroamination of Allenes: Asymmetric N-Allylation of Amino Acids and Peptides

In the growing field of peptidomimetics, there is a constant need for new synthetic methods to generate new bioactive compounds. Herein, we present an atom-economic approach for the branched-selective allylation of aliphatic amine moieties of α-amino acids and small oligopeptides. This Rh-catalyzed hydroamination of allenes with a commercially available ligand forms a new stereocenter, often chemoselectively, in a catalyst-controlled manner, providing high yields and stereoselectivities without the need for an additive. The method is shown to be effective in gram scale without the need for column chromatography for purification, and ready-to-use allylated substrates for solid-phase peptide synthesis can be synthesized in two steps from the products of the catalysis.