Asymmetric Friedel-Crafts Reaction of 4,7-Dihydroindoles with Nitroolefins by Chiral Brønsted Acids under Low Catalyst Loading
作者:Yi-Fei Sheng、Gong-Qiang Li、Qiang Kang、An-Jiang Zhang、Shu-Li You
DOI:10.1002/chem.200900033
日期:2009.3.23
Slowly does it! By adding the substrate by a syringe pump, a highly efficient Friedel–Craftsreaction of 4,7‐dihydroindoles with nitroolefins was realized with 0.5 mol % of a chiral phosphoric acid. The Friedel–Crafts alkylation, together with a subsequent oxidation of the product, led to 2‐substituted indoles in excellent enantiomeric excesses, which can be easily transformed to enantioenriched t