Racemic Vinylallenes in Catalytic Enantioselective Multicomponent Processes: Rapid Generation of Complexity through 1,6‐Conjugate Additions
作者:Youming Huang、Sebastian Torker、Xinghan Li、Juan del Pozo、Amir H. Hoveyda
DOI:10.1002/anie.201812535
日期:2019.2.25
Racemic vinylallenes are shown to be effective substrates for catalytic multicomponent diastereo‐ and enantioselective 1,6‐conjugate addition of multifunctional allyl moieties to easily accessible α,β,γ,δ‐unsaturated diesters. Reactions may be catalyzed by 5.0 mol % of a readily accessible NHC‐Cu complex at ambient temperature, and other than a vinylallene, involve B2(pin)2 and an α,β,γ,δ‐unsaturated
外消旋乙烯基烯丙烯是有效的底物,可将多功能烯丙基部分催化多组分非对映和对映选择性的1,6-共轭加成到易于获得的α,β,γ,δ-不饱和二酯中。在环境温度下,可用5.0 mol%的NHC-Cu络合物轻松催化反应,并且除乙烯基烯丙基外,还涉及B 2(pin)2和α,β,γ,δ-不饱和二酯。各种乙烯基丙二烯被转化为具有Z-三取代烯基-B(pin)部分,乙烯基,β,γ-不饱和二酯单元和邻位立体异构中心的产物,产率高达67%,87:13 Z / E比率大于98:2 dr和98:2 er进行了化学选择性修饰,涉及烯基-B(pin),乙烯基或1,2-二取代的烯烃部分,以证明其多功能性和实用性。基于机理和DFT研究的立体化学模型证明了中间体铜烯丙基物种的动力学行为,并说明了各种选择性特征。