Planar-Chiral Cyclopentadienyl-Ruthenium-Catalyzed Regio- and Enantioselective Asymmetric Allylic Alkylation of Silyl Enolates under Unusually Mild Conditions
report the asymmetric allylic alkylation of allylic chlorides with silyl enolates as a carbon nucleophile using a planar‐chiral cyclopentadienyl‐ruthenium (Cp′Ru) catalyst. The reaction proceeds under unusually mild conditions to give the desired branched products with complete regioselectivity and high enantioselectivity, and reactive functional groups, such as aldehyde, can be tolerated. In this reaction
A new synthetic route to optically active unsaturated gamma- and delta-lactones has been demonstrated via asymmetric allylic carboxylation with a planar-chiral Cp'Ru catalyst and ring-closingmetathesis reaction with a Grubbs II catalyst, and successfully applied to the enantioselective synthesis of (R)-(-)-massoialactone.