Synthesis Of 5,6-Dihydro-2(1H)-Pyridone And 5,6-Dihydro-?-Pyrone By Bond-Promoted Ru-Catalyzed Ring-Closing Metathesis

Olefin metathesis has been widely used in synthesis field,especially in the total synthesis of natural products or active intermediates and active drug molecules.Olefin metathesis has been one of the most powerful tools for organic synthesis researchers.Based on the preliminary work of this group,the research on the large-resistance RCM reaction promoted by hydrogen bonding was carried out in the paper.The promotion of olefin metathesis by hydrogen bonding was used to construct 5,6-dihydro-?-pyridyl.Two kinds of pronuclear structures with potential medicinal properties,ketone and 5,6-dihydro-2(1H)-pyridone,were studied for the application range of the substrate for the six-membered ring by RCM reaction.The structural elements that influence the reaction and the possible reaction mechanisms were explored.In addition,a method for better removal of antimony impurities was found during the research.The main contents are as follows:1.Based on the previous work of our team,a hg-ii-catalyzed method for the construction of 5,6-dihydro-?-Pyranone catalyzed by 2-hydroxymethacrylic acid fragments was developed for double-bond tetrasubstitution of 5,6-dihydro-?-Pyranone.The conditions of the reaction and the application range of the substrate were studied.2.The synthesis of 5,6-dihydro-2(1H)-pyridinone with double-bond trisubstituted 5,6-dihydro-2(1H)was developed by hydrogen bonding to promote the rcm reaction.It was found that the electron-rich side chain had a significant effect on the reaction.It provides a possible strategy for the synthesis of polysubstituted 5,6-dihydro-2(1H)-pyridone and heterocycles.3.In the process of rcm reaction promoted by hydrogen bond,it was found that a variety of Ruthenium impurities were formed by using HG-IIcatalyst in the reaction process,and it was difficult to remove the Ruthenium-containing impurities by column chromatography.We found a class of polyamine reagents which can effectively complex with ruthenium impurities,and set up a kind of simple post-processing method.