Cinchona-based squaramide-catalysed cascade aza-Michael–Michael addition: enantioselective construction of functionalized spirooxindole tetrahydroquinolines
作者:Wen Yang、Da-Ming Du
DOI:10.1039/c3cc44930k
日期:——
An efficient enantioselective cascadeaza-Michael-Michael addition reaction catalysed by a chiral bifunctional tertiary amine-squaramide catalyst has been developed. This cascadereaction proceeded well under mild conditions, furnishing highly functionalized spirooxindole tetrahydroquinolines with three contiguous stereocenters in excellent yields with excellent diastereoselectivities (>25:1 dr) and
An unprecedented organocatalyzed aerobic oxidative Robinson annulation of 2-isocyanochalcones with active methylene ketones was developed for the expedientsynthesis of phenanthridines and hydrophenanthridinones in high to excellent yields.
Highly stereoselective construction of tetrahydroquinolines via cascade aza-Michael-Michael reaction: Formal [4+2] cycloaddition of β,γ-unsaturated α-ketoesters with 2-aminochalcones
作者:Cong Duan、Yongqi Yao、Ling Ye、Zhichuan Shi、Zhigang Zhao、Xuefeng Li
DOI:10.1016/j.tet.2018.10.053
日期:2018.12
An efficient cascade aza-Michael-Michael sequence for the preparation of tetrahydroquinolines has been established. Three contiguous stereogenic centers are created with high levels of enantioselectivities (79–99% ee) and exclusive diastereoselectivities in the presence of a bifunctional squaramide. This approach is compatible with a broad range of β,γ-unsaturated α-ketoesters and 2-aminochalcones
The first N-heterocyclic carbene-catalyzed stereoselective aza-Michael–Michael–lactonization cascade reaction of 2′-aminophenylenones and 2-bromoenals for the construction of chiral functionalized tetrahydroquinolines with three consecutive stereogenic centers has been achieved in high yields (up to 98%) with excellent diastereo- (>25:1) and enantioselectivities (up to 98.7% ee).
single operation, and represent novel protocols for the expedient synthesis of both aromatic and partially aromatic pyrrolo[2,3‐c]quinoline derivatives from readily available precursors under metal‐free conditions. Notably, tetrahydro‐3H‐pyrrolo[2,3‐c]quinolones that bear three adjacent stereocenters were obtained in a highly diastereoselective manner.
已成功开发了甲苯磺酰基甲基异氰化物和异氰基乙酸酯与2-亚甲基氨基查耳酮作为aza-1,5-dielectrophiles的串联环化-环化反应。这些多米诺骨转化具有在一次操作中同时形成三个键和两个环的特点,并且代表了在无金属条件下方便地从易得的前体合成芳族和部分芳族吡咯并[2,3- c ]喹啉衍生物的新颖方法。值得注意的是,以高度非对映选择性的方式获得了带有三个相邻立体中心的四氢-3 H-吡咯并[2,3- c ]喹诺酮。