Palladium-Catalyzed Asymmetric Allylation With Dienes,Allenes,and Alkynes

Dienes,allenes and alkynes are the basic raw materials in petrochemical and coal chemical industries,and they are widely used in medicine,pesticide,materials and other fields.The efficient conversion of these unsaturated hydrocarbons has always been a hot spot in synthetic chemistry research.The reaearch theme of thesis focuses on the development of asymmetric reactions with dienes,allenes and alkynes via πallylpalladium intermediates.First,we have developed an asymmetric diamination of 1,3-dienes using readily available dialkylureas as amination reagents.The compatibility of chiral pyridineoxazoline ligand with the catalytic activity of the cationic palladium(Ⅱ)complex was key for the realization of the stereoselective oxidative diamination.By this method,gram-scale synthesis is feasible and allows for an efficient access to chiral Salen-type ligands.Second,we developed a palladium catalyzed cascade sp2 C-H functionalization/asymmetric allylation with aryl α-diazoamides and allenes.This reaction provided an efficient approach to construct chiral 3,3’-disubstituted oxindole derivatives in high levels of yield and enantioselectivity.In addition,the products can be applied for synthesizing potentially bioactive molecules through simple transformation.Finally,we realized an asymmetric α-pentadienylation between α-aryl aldehydes and cyclopropylacetylenes via a metal/organo cooperative catalysis,providing lots ofα-quarternary chiral aldehydes with high levels yield and enantioselectivity.Notably,This work is the first case of asymmetric pentadienylation using readily available cyclopropylacetylene and its derivatives.