Palladium-Catalyzed Asymmetric Functionalization Of 1,3-Dienes

1,3-dienes are readily available compounds wildly used in organic synthesis and chemical industries.Palladium-catalyzed asymmetric functionalization of 1,3-dienes is of great importance as it offers an efficient way to access structurally diverse chiral compounds.Aiming at the challenges in this field,such as the difficulties for the control of chemoselectivity and stereoselectivity,narrow substrate scopes,we focused on the development of efficient catalyst systems for palladium-catalyzed asymmetric functionalization of 1,3-dienes.Besides,to explore new stereocontrol modes,the related asymmetric Heck-type functionalization of allylic alcohols was also investigated.First,we have developed the palladium-catalyzed decarboxylative allylation of ?-keto acids with 1,3-dienes to obtain ?,?-unsaturated ketones in up to 99%yield.Preliminary investigation of the asymmetric version of this reaction.found difluorphos to be the optimal chiral ligand at present,which gave chiral ?,?-unsaturated ketone with 80%yield and up to 83:17 er.Secondly,we have developed a chiral Pd-catalyzed cascade sp2 C-H functionalization/intramolecular asymmetric allylation of N-alkoxyaryl amides and 1,3-dienes using oxygen as the oxidant and a novel chiral Pyox as the ligand.The method also has particular applicability to construct various chiral heterocycles from simple starting materials,which may could be robustly applied to the synthesis of bioactive molecules.Finally,we have developed chiral anion-mediated enantioselective Heck-Matsuda reactions with challenging acyclic alkenyl alcohols as the substrates,extending the application territory of chiral anion phase transfer in transition metal catalysis.Various chiral ketones could be obtained with up to 97:3 er.