Enantioselective Synthesis of Tetrahydropyrano[3,4-b]indoles Catalyzed by Chiral N-Triflyl Phosphoramide via Intramolecular Friedel-Crafts Alkylation Reaction
A highly efficient intramolecular enantioselective Friedel-Crafts alkylation reaction of indolyl enones utilizing chiral N-triflyl phosphoramide catalyst is described. Various tetrahydropyrano[3,4-b]indoles (THPI) have been afforded with excellent yields and up to 98% ee.
Asymmetric Construction of Polycyclic Indoles through Olefin Cross-Metathesis/Intramolecular Friedel-Crafts Alkylation under Sequential Catalysis
作者:Quan Cai、Zhuo-An Zhao、Shu-Li You
DOI:10.1002/anie.200903462
日期:2009.9.21
A synthetic shortcut: A highly efficient cascade reaction (see scheme) led to polycyclic indoles with excellent enantioselectivity. The combination of the two steps through sequentialcatalysis enables the use of more readily available starting materials and makes the synthesis more practical. Boc=tert‐butoxycarbonyl.