Asymmetric Conjugate Addition of 1,3-Diketone to Nitroalkenes Catalyzed by Bifunctional Thiourea-Amide Organocatalysts

Abstract

New bifunctional chiral thiourea-amide organocatalysts were developed. Their applications in asymmetric conjugate addition of 2,4-pentandione to various nitroalkenes were investigated. The corresponding adducts were obtained in excellent yields with high enantioselectivities up to 94% ee in present of 1 mol% catalyst. The catalytic system could also suit for various nitroalkenes bearing electron-donating or electron-withdrawing groups. The preliminary structure-activity relationship study reveals that the acyl group in pyrrolidine N position plays an important role in catalyzing the reaction.

New Application of β,γ-Unsaturated α-Ketoesters in Asymmetric Catalysis

“…β,γ-不饱和 α-酮酸酯可以通过碳碳双键作为亲双烯 + 图式 28 烯丙基硼酸与 β,γ-不饱和 α-酮酸酯的烯丙基硼化/ oxa-cope 重排串联反应 Scheme 28 Catalytic asymmetric allylboration/oxy-cope rearrangement of allylboronic acids with β,γ-unsaturated α-ketoester 体与共轭双烯体进行 D-A 反应生成环己烯衍生物. 冯小 明课题组 [37] 使用 Zn(OTf Michael 加成反应是亲核物种对 α,β-不饱和体系进 行的 1,4-亲核加成, 是常见的构筑新手性中心的方法之 一 [42] . 2016 年, 周正洪等 [43]…”