Enantioselective Friedel–Crafts Alkylation Reactions of β‐Naphthols with Donor–Acceptor Aminocyclopropanes

The enantioselective Friedel–Crafts alkylation reaction of β‐naphthols with donor–acceptor aminocyclopropane was developed. In the presence of a copper complex derived from Cu(OTf) 2 and bisoxazoline, a series of γ‐substituted γ‐aminobutyric acid derivatives were obtained with good yields (up to 98 %) and excellent enantioselectivities (up to 98 %). Using this catalytic system, the 2‐amino cyclopropane‐1,1‐dicarboxylate was obtained with high enantiomeric excess (up to 98 %) by an efficient kinetic resolution ( s values of up to 90). The Friedel–Crafts alkylation product could be transformed into a tetracyclic 1,3‐oxazine derivative.