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. The enantioselective Friedel–Crafts alkylation reaction of β‐naphthols with donor–acceptor aminocyclopropanes was developed for preparing chiral γ‐substituted aminobutyric acid derivatives. With this catalytic system, 2‐amino cyclopropane‐1,1‐dicarboxylate was obtained with high enantiomeric excess by an efficient kinetic resolution. The Friedel–Crafts alkylation product could be transformed into a tetracyclic 1,3‐oxazine derivative.