Total Synthesis Of Alkaloids Dactyllactone A, Korupensamine A, B And Michellamine B Via Pd/NBE Cooperative Catalysis

The Catellani reaction is an efficient cascade reaction that can construct multiple chemical bonds at the same time.It has a history of more than 20 years since it was reported by the Italian scientist Professor Catellani in 1997.With the continuous efforts of scientific researchers,the Catellani reaction has played an important role in the total synthesis of natural products,the synthesis of functional materials as well as the synthesis of functional molecules.The goal of this thesis is to develop efficient synthetic methodology to achieve high-efficiency total synthesis of natural products.It developed a new Catellani reaction that uses aziridine as the alkylation reagent and alkyne as the terminating reagent,which can quickly construct o-alkynyl aromatic acetylenes amine compounds.By using this method as the key step,the efficient total synthesis of alkaloids dactyllactone A,korupensamine A,B and michellamine B was completed.For the anti-inflammatory alkaloid dactyllactone A,we have used Catellani reaction,intramolecular SN2-Michael cascade reaction,Sonogashira coupling reaction,gold-catalyzed cyclization reaction,and ultraviolet light-promoted olefin isomerization cyclization cascade reaction to achieve the construction of the skeleton of dactyllactone A.Then by removing the protective group and reductive amination reaction,we have completed the first total synthesis of dactyllactone A with the longest 7 linear steps.For the anti-HIV alkaloid michellamine B and the anti-malarial alkaloid korupensamine A,B,we completed the efficient total synthesis of the longest 7 linear steps of korupensamine A,B and that of the longest 9 linear steps of michellamine B by using Catellani reaction,gold-catalyzed cyclization reduction cascade reaction,ruthenium-catalyzed allylation reaction,intramolecular Friedel-Crafts acylation aromatization cascade reaction,Suzuki coupling reaction as well as Negishi coupling.