Regioselective β-Csp-Arylation of β-Alanine: An Approach for the Exclusive Synthesis of Diverse β-Aryl-β-amino Acids.

An approach for the synthesis of a variety of new β-aryl-β-amino acids has been developed via a palladium-catalyzed auxiliary-directed regioselective Csp-H arylation of the unactivated β-methylene bond of β-alanine. The use of 8-aminoquinoline amide as an auxiliary efficiently directs the desired regioselective β-Csp-H functionalization. The developed protocol enables the easy and straightforward access to several high-value β-aryl-β-amino acids useful for peptide engineering, starting from inexpensive and readily available β-alanine precursors in moderate to excellent yields.