Intramolecular Edge-to-Face Aromatic π−π Interaction in Optically Active Ruthenium−Allenylidene Complexes for Enantioselective Propargylic Substitution Reactions

Novel optically active ruthenium−allenylidene complexes are prepared and characterized by X-ray crystallography. Intramolecular edge-to-face aromatic π−π interaction in the allenylidene complexes is observed between two phenyl groups in the allenylidene and chiral ligands, which may play a critical role in achieving the high enantioselectivity in the enantioselective propargylic substitution reactions of propargylic alcohols with nucleophiles.