Synthesis of α,α-disubstituted amino acids based on tandem reaction of dehydroamino acid derivatives

The formation of all-substituted sp3-hybridized carbon-center was investigated via tandem reaction of dehydroamino acid derivatives. The diethylzinc-promoted reaction of dehydroamino acid derivatives with acid anhydride or π-allyl palladium complex proceeded smoothly to afford α,α-disubstituted amino acids via a radical and anionic carbon–carbon bond-forming processes. The tandem reductive reaction of N-phthaloyl dehydroalanine also proceeded effectively by using Bu3SnH and Pd(PPh3)4.