Catalytic Asymmetric Synthesis of Unnatural Amino Acids

Significance

The authors report the asymmetric synthesis of unnatural amino acids through asymmetric allylic substitution followed by a cross-­metathesis reaction. The sequential catalytic ­systems using Cu, Ru and Ir are all well controlled with high stereoselectivities and, thus, the method provides stereodivergent access to unnatural amino acids.