The Catalytic Enantioselective Claisen Rearrangement of an Allyl Vinyl Ether

Almost 90 years after it was first described by Ludwig Claisen, a catalyzed enantioselective Claisen rearrangement has been implemented for the first time. Chiral copper(II) bis(oxazolines) catalyzed the Claisen rearrangement of 2-alkoxycarbonyl-substituted allyl vinyl ethers with enantiomeric excesses of 80–90 % (see scheme).