The enantioselective ketimine-ene reaction is one of the most challenging stereocontrolled reaction types in organic synthesis. In this work, catalytic enantioselective ketimine-ene reactions of 2-aryl-3H-indol-3-ones with α-methylstyrenes were achieved by utilizing a B(C6 F5 )3 /chiralphosphoricacid (CPA) catalyst. These ketimine-ene reactions proceed well with low catalyst loading (B(C6 F5 )3
Asymmetric Synthesis of C2-Quaternary Indolin-3-ones Enabled by N-Heterocyclic Carbene Catalysis
作者:Shuaishuai Fang、Shiyi Jin、Rui Ma、Tao Lu、Ding Du
DOI:10.1021/acs.orglett.9b01823
日期:2019.7.5
(NHC)-catalyzed formal [4 + 2] annulation of 2-aryl-3H-indol-3-ones with α,β-unsaturated carboxylicacids bearing γ-H was developed via an in situactivationstrategy. The reaction involves the γ-addition of vinyl enolates to the unique cyclic ketimines to afford chiral tricyclic indolin-3-ones with a quaternary carbon center at 2-position. This protocol provides a rapid and enantioselective pathway to
Organocatalytic Enantioselective Aza-Friedel-Crafts Reaction of Cyclic Ketimines with Pyrroles using Imidazolinephosphoric Acid Catalysts
作者:Shuichi Nakamura、Nazumi Matsuda、Mutsuyo Ohara
DOI:10.1002/chem.201601573
日期:2016.7.4
Organocatalytic enantioselective aza‐Friedel–Crafts reactions of cyclic ketimines with pyrroles or indoles were catalyzed by imidazoline/phosphoric acidcatalysts. The reaction was applied to various 3H‐indol‐3‐ones to afford products in excellent yields and enantioselectivities. The chiral catalysts can be recovered by a single separation step using column chromatography and are reusable without further
Asymmetric Brønsted Acid-Catalyzed Friedel-Crafts Reactions of Indoles with Cyclic Imines - Efficient Generation of Nitrogen-Substituted Quaternary Carbon Centers
作者:Magnus Rueping、Sadiya Raja、Alberto Núñez
DOI:10.1002/adsc.201000952
日期:2011.3.7
A new enantioselective Brønsted acid‐catalyzed Friedel–Crafts reaction of indole with cyclicimines has been develeoped. This organocatalytic reaction provides for the first time optically active indolindolinone derivatives in high yields and with excellent enantioselectivities (up to 91% ee) under mild reaction conditions.