Diastereodivergent Asymmetric 1,3‐Dipolar Cycloaddition of Azomethine Ylides and β‐Fluoroalkyl Vinylsulfones: Low Copper(II) Catalyst Loading and Theoretical Studies
作者:Feng Cheng、Subarna Jyoti Kalita、Zhen‐Ni Zhao、Xing Yang、Yan Zhao、Uwe Schneider、Norio Shibata、Yi‐Yong Huang
DOI:10.1002/anie.201908227
日期:2019.11.11
-catalyzed asymmetric 1,3-dipolar cycloaddition using β-fluoroalkyl alkenyl arylsulfones as dipolarophiles and glycine/alanine iminoesters as azomethine ylide precursors has been developed. Remarkably, a catalyst loading as low as 0.5 mol % is highly efficient. Accordingly, a wide range of enantioenriched 3-fluoroalkyl pyrrolidines, as well as Δ2 -pyrroline and pyrrole derivatives, are generated in good
已经开发出使用β-氟代烷基烯基芳基砜作为双极性亲和剂和甘氨酸/丙氨酸亚氨基酯作为偶氮甲碱叶立德前体的CuII催化的不对称1,3-偶极环加成反应。显着地,低至0.5mol%的催化剂装载是高度有效的。因此,以高至优异的收率和高的不对称诱导率,产生了多种对映体富集的3-氟烷基吡咯烷以及Δ2-吡咯啉和吡咯衍生物。这种合成方法是非对映异构的,因为在吡咯烷核的C 2上,1,8-二氮杂双环[5.4.0] undec-7-烯介导的差向异构作用可以将外加成加成物转化为相应的外加加成。DFT计算得出的自由能曲线表明,将1,3偶极迈克尔加成是速率和对映体确定步骤,