Chiral Phosphoric Acid Catalyzed Asymmetric Friedel–Crafts Alkylation of Indoles with Simple α,β‐Unsaturated Aromatic Ketones

Abstract

Abstract Asymmetric Michael‐type Friedel–Crafts (F‐C) alkylations of indoles with nonchelating α,β‐unsaturated aromatic ketones catalyzed by a chiral H 8 ‐BINOL‐based phosphoric acid were investigated. The reactions took place smoothly in the presence of only 2 mol‐% of catalyst at room temperature to afford the desired F‐C alkylation products in good yields and with moderate enantioselectivities.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)