The Research On Transition-Metal-Catalyzed Reaction Based On Enynones As Carbene Precursors

Carbene precursors catalyzed by transition metal reaction is one of the important branch of organic chemistry,which could be constructed C-C or C-X bonds efficiently,it is very popular way among organic chemists.Our work is based on the study of carbene precursors catalyzed by transition metal reaction.The reaction research was carried out with enyne ketone,which is an economic,efficient carbene precursor as the research objection.The first chapter is mainly elaborated from two aspects.Firstly,the research progress of three commonly used transition metal catalysts in carbene reaction is introduced.It also introduces its characteristics and the main carbene chemical reactions involved.Among them,the main research transition metals in carbene reaction catalyzed by transition metal,includes Rh,Cu,Pd and other metals.This chapter describes the reaction types of these transition metals and the progress in chiral catalysis.In the second chapter,we introduced the study of the palladium catalyzed reaction of X-H and C-H insertion firstly.Some ligands in carbine reactions have a better chiral induction effect with palladium catalyst.Based on this,we developed palladium catalyzed asymmetric intramolecular C(sp~3)-H insertion reaction,based on the non-diazotic method.Under the control of catalysts and ligands,a C(sp~3)-H insertion product with high enantioselectivity was obtained.The reaction also has a certain substrate suitability in the expansion of substrate.The literature shows that in the carbene reaction,palladium has different catalytic activities compared to other transition metals such as rhodium or copper.The literature also indicates that the palladium has the different properties between rhodium and copper in carbine reaction,then,through DFT,it was found that the rate-determining step of the C-H insertion reaction is forming a ring not the hydrogen migration.It is disfavored kinetics experiments.In the third chapter,the heteroarene-fused of fluorens exhibit unique electronic and photonic properties,and the Schmittel-type cyclization of enyne allene is one of the most efficient methods for the synthesis of polyfused fluorene derivatives.The aryl group need pre-built.In our continuous efforts in utilizing enynals/enynones as reliable and safe carbene sources for furan carbene-mediated cascade transformations.A new method for the synthesis of furan-/benzo-fused fluorenes through copper(I)-catalyzed coupling of conjugated enynones,α-diazocarbonyl and N-tosylhydrazones compounds with dialkynylbenzenes has been developed.According to machanistic investigation traction,we could not exclude the diradical intermediate.This process includes 5-exo-dig cyclization,carbene migratory insertion,Schmittel cyclization and 1,5-H transfermation.The obvious advantages of wide substrate scopes,mild reaction conditions,and high atom efficiency make this system highly appealing for the construction of six-substitued benzofuran-embedded fluorenes in a one-pot manner.