Construction Of Heterocyclic Compounds Through Gold-Catalyzed Reaction Of Diynes

Because of the unique catalytic properties,homogeneous gold catalysis has been found certain advantages in construction of heterocyclic compounds.Over the past few decades,gold-catalyzed reactions of diynes have been extensively explored and demostraterd great potential in the synthesis of natural products and drugs.This thesis includes three parts:In the first part,we briefly introduce the research progress on gold-catalyzed reactions of alkynes,diyanmides,and the synthetic application of gold-catalyzed reaction of 1,ndiynes in construction of cyclic products.In the second part,a gold-catalyzed cycloisomerization of readily available 1,5-diyne to construct 1,3,4-trisubstituted pyrroles was described.Mechanistic studies indicated that a key vinyl cationic intermediate was produced.Through this work,a mild and atom economic method was provided for the synthesis of polysubstituted pyrroles.In the third part,we described a gold-catalyzed cascade reaction of 1,2-difunctionalization/[4+2]cycloaddition of conjugated diynamides,giving bridged polycyclic lactams in moderate to good yields.The formation of unconjugated ynone is vital for the construction of polycyclic skeleton.This method is operationally simple,possessing mild reaction conditions and good atom economy,hence demonstrating its synthetic potential in polycyclic product synthesis,and further providing a novel and efficient approach to obtain this kind of cyclic compounds.