화학공학소재연구정보센터
Journal of the American Chemical Society, Vol.129, No.48, 14866-14866, 2007
Palladium-catalyzed synthesis of spiro[2.4]heptanes: Ligand-dependent position control in the nucleophilic attack to a pi-allyipalladium intermediate
A palladium-catalyzed intermolecular cycloaddition of gamma-methylidene-delta-valerolactones with electron-deficient olefins has been developed for the synthesis of spiro[2.4]heptanes with high selectivity through a nucleophilic ring closure to the central carbon of a pi-allyipalladium intermediate. It was found that the course of the reaction is dependent on the ligand employed, and selective [4 + 2] cycloadditions can also be achieved by the use of a bulky monophosphine ligand.