((eta)^5-Triphenylindenyl)Ru(CO)2Cl: A New Ruthenium Catalyst for the Highly Efficient Racemization of Chiral 1-Phenylethanol at Room Temperature

A new ruthenium complex, ((eta)^5-triphenylindenyl)Ru(CO)2Cl, was synthesized and successfully applied in the racemization of (S)-1-phenylethanol at room temperature. Instead of potassium tert-butoxide, stronger bases such as sodium hydride and n-butyllithium were used to activate the precatalyst. In situ NMR experiments revealed the presence of ruthenium hydride as a key intermediate in the catalytic cycle.