Planar‐Chiral Cyclopentadienyl‐Ruthenium‐Catalyzed Regio‐ and Enantioselective Asymmetric Allylic Alkylation of Silyl Enolates under Unusually Mild Conditions

We 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 system, Cp′Ru plays an important role in activating both silyl enolate and allylic chloride.