Preparation of Organoaluminum Reagents from Propargylic Bromides and Aluminum Activated by PbCl₂ and Their Regio- and Diastereoselective Addition to Carbonyl Derivatives

摘要

Various propargylic and allenic aluminum reagents have been easily prepared by a direct insertion of aluminum into propargylic bromides in the presence of PbCl₂ (1 mol %). These organoaluminum reagents react with carbonyl compounds to afford the corresponding allenic alcohols or homopropargylic alcohols in good to excellent yields with high regio- and diastereoselectivity.