Catalytic Asymmetric 1,3-Dipolar Cycloaddition of Azomethine Ylides with α,β-Unsaturated Ketones

alpha,beta-Unsaturated ketones are no longer the missing dipolarophiles in catalytic asymmetric 1,3-dipolar cycloaddition of azomethine ylides. In the presence of Cu-1-Fesulphos complexes as catalysts (5 mol %), these substrates combine high reactivity, wide substitution tolerance, moderate to good endo/exo selectivities, and high enantiocontrol. The endo/exo-diastereoselectivity of the reaction is strongly dependent on the cis or trans nature of the enone moiety.