Enantioselective Rhodium Enolate Protonations. A New Methodology for the Synthesis of β²-Amino Acids

Rhodium-catalyzed conjugate addition of an aryl boronic acid to α-methylamino acrylates followed by enantioselective protonation of the oxa-π-allylrhodium intermediate provides access to aryl-substituted β²-amino acids. The impact of the different variables of the reaction on the levels of enantioselectivity has been assessed.