Efficient Propargylation of Aldehydes and Ketones Catalyzed by Titanocene(III).

We describe a novel method for the propargylation of a wide range of aldehydes and ketones catalyzed by titanocene(III) complexes under mild reaction conditions and compatible with many functional groups. Homopropargylic alcohols are obtained as the sole products even when ketones are used as starting materials, which is unusual in Barbier-type propargylations.