Enantioselective Friedel-Crafts reaction of indoles with arylidene malonates catalyzed by iPr-bisoxazoline-Cu(OTf)2

The cheap and simple Pr-i-bisoxazoline-Cu(OTf)(2) proves to be an efficient catalyst in the asymmetric Friedel-Crafts reaction of indole with arylidene malonates. In (BuOH)-Bu-i, the S-enantiomer was obtained in up to 97% ee, while the opposite enantiomer was obtained in up to 78% ee in CH2Cl2 or TTCE.