Stereoselective Synthesis of Spirooxindoles by Palladium-Catalyzed Decarboxylative Cyclization of γ-Methylidene-δ-valerolactones with Isatins
                                
                                    
                                        作者:Ryo Shintani、Shin-ya Hayashi、Masataka Murakami、Momotaro Takeda、Tamio Hayashi                                    
                                    
                                        DOI:10.1021/ol901348f
                                    
                                    
                                        日期:2009.8.20
                                    
                                    A new synthetic method of spirooxindole derivatives has been developed by way of a palladium-catalyzed decarboxylative cyclization of gamma-methylidene-delta-valerolactones with isatins. By employing a newly prepared phosphoramidite ligand, the reaction proceeds smoothly with excellent diastereoselectivity. Preliminary results of its application to asymmetric catalysis using a chiral phosphoramidite ligand are also described.