Regioselective Pd-Catalyzed Hydroalkynylation of Allenyl-Containing α-Amino Acid Derivatives with Terminal Alkynes

An efficient access to the novel representatives of α,α-disubstituted α-amino acids with 1,3-enyne unit located at their side chain has been elaborated. The method is based on Pd(II)-catalyzed hydroalkynylation of α-allenyl-α-dimethylamino esters with terminal acetylenes. The developed strategy is the first example of the metal-catalyzed allene-alkyne coupling to provide a convenient route to new unsaturated α-amino acid derivatives in good yields and high selectivity.