Propargylic and Allenic Carbocycle Synthesis through Palladium-Catalyzed Dearomatization Reaction

The dearomatization reaction of benzylic chlorides (1a-k), chloromethylnaphthalenes (1l-r), and naphthalene allyl chlorides (3a-d) with allenyltributyltin proceeded smoothly in the presence of Pd(PPh(3))(4) catalyst at room temperature to give the corresponding propargylated and/or allenylated dearomatization products (5, 5'; 6, 6'; and 7, respectively) in high to fair yields. The reaction of 1a-k proceeded smoothly in the presence of TBAF, whereas it was not necessary to use TBAF as an additive in the reactions of 1l-k and 3a-d. These reactions provided a new and efficient method for the synthesis of propargylic and allenic carbocycles.