Copper-catalyzed enantioselective 1,4-conjugate addition of dialkylzinc reagents to α,β- and α,β,γ,δ-unsaturated ketones
作者:Rukeya Rexiti、Jian Lu、Feng Sha、Xin-Yan Wu
DOI:10.1016/j.tet.2019.05.029
日期:2019.6
An enantioselective Cu(II)-catalyzed conjugate addition of dialkylzinc reagents to α,β- or α,β,γ,δ-unsaturated ketones with chiral cyclohexane-based amidophosphine ligands was developed. With 2 mol% of Cu(OAc)2·H2O/L5, the conjugate addition of diethylzinc to α,β-unsaturated ketones was achieved in good-to-excellent yields (up to 98%) and high enantioselectivities (up to 92% ee). This catalytic system
开发了一种手性环己烷基酰胺基膦配体的对映选择性Cu(II)催化二烷基锌试剂共轭加成到α,β-或α,β,γ,δ-不饱和酮上的方法。使用2 mol%的Cu(OAc)2 ·H 2 O / L5,可以将二乙基锌共轭添加到α,β-不饱和酮中,收率良好至优异(最高98%),对映选择性高(最高90%)。 92%ee)。该催化体系显示对于将Et 2 Zn 1,(4 - E)加成到(2 E,4 E)-1,5-二苯基戊-2,4-dien-1-one上是有效的,产率为85%,90 %ee。另外,Cu(OTf)2 / L11为1摩尔%,α,β,γ,δ-不饱和酮的共轭加成反应具有1,4-区域选择性,良好的收率(79-86%)和出色的对映选择性(高达97%ee)。