Abstract
Asymmetric Michael-type Friedel–Crafts (F–C) alkylations of indoles with nitroolefins catalyzed by a chiral H8-BINOL-based phosphoric acid were investigated. The reactions took place very smoothly in the presence of only 5 mol-% of catalyst at room temperature to afford the desired F–C alkylation products in good yields and with moderate enantioselectivities.
GRAPHICAL ABSTRACT
Acknowledgments
This work is supported by Tianjin Natural Science Foundation (08JCYBJC26900), the Research Fund for Young Scientist (No. 52LX29), Tianjin Normal University, and Tianjin High School Foundation for Development of Science and Technology (2008ZD09).