Copper-catalyzed asymmetric 1,4-conjugate addition of Grignard reagents to linear α,β,γ,5-unsaturated ketones

摘要

A highly regioselective and enantioselective copper-catalyzed 1,4-conjugate addition of Grignard reagents to linear α,β,γ,δ-unsaturated ketones was developed. The 1,4-addition products were obtained regioselectively in high yields with up to 98% ee. Conjugate addition (CA) as a practical and efficient strategy to construct carbon-carbon bonds is of great interest1 Controlling the regio- and stereo-selectivity of a reaction is a significant challenge in organic synthesis, especially in asymmetric conjugate additions (ACA). Excellent regio- and stereo-selectivity have been achieved in reactions involving transition metal-catalyzed α,β-unsaturated Michael acceptors.