Copper (I)-catalyzed asymmetric addition of terminal alkynes to β-Imino esters: An efficient and direct method in the synthesis of chiral β³-alkynyl β^2,2-dimethyl amino acid derivatives

The first catalytic asymmetric addition of terminal alkynes to β-imino esters was carried out using chiral copper(I) complexes as catalysts under mild reaction conditions, providing an efficient and direct synthetic approach to β3-alkynyl β2,2-dimethyl amino esters with yields of 73-97% and 48-90% ee. The rich chemistry of the alkynyl functionality makes the present method a powerful and versatile approach to a wide range of optically active β2,2-dimethyl amino acid derivatives. KGaA.