Ruthenium‐Catalyzed Asymmetric Propargylic Substitution Reactions of Propargylic Alcohols with Acetone

Enantioselective propargylic substitution reactions of propargylic alcohols with acetone catalyzed by a diruthenium complex gives the propargylic alkylated products in good yields with up to 82 % ee. A π–π interaction of phenyl rings between the ligand and allenylidene moieties is considered to play a crucial role in achieving such a high selectivity (see scheme; Cp*=pentamethylcyclopentadiene).