Palladium-catalyzed Arylation Of Furan Access To N,O-spiroketals And ?-aryl Furan Compounds

Transition metal-catalyzed difunctionalization of alkenes gained extensive attention in recent years,including oxyamidation,dioxygenation,diamination,alkoxylarylation,aminoarylation,etc as representative reactions.Among them,palladium-catalyzed oxidative difunctionalization is a hot topic in chemical frontiers.In bioscience and organic synthetic chemistry,furan derivatives show as a kind of important reaction substrates,for its similar properties to olefins,1,3-diene and 1,4-dicarbonyl compounds.According to these close properties,many reactions taking place on simple olefins can occur on furan derivatives,modifying existing natural products as well as the establishing new and complex skeleton in natural products.In this essay,the arylation of furan derivatives under different palladium catalysis system was studied.This thesis is divided into the following two parts:1.Pd???/O₂ catalyzed arylation of?-aminoalkyl furan derivatives.In this chapter,we firstly introduced sevarel achievements of dearomatization difunctionalization of furan compounds in our group.Afterwards,some research on arylation with the reactant N-?3-?furan-2-yl?propyl?-4-methylbenzenesulfonamide was described in detail.It could be found that N,O-spiroketals were obtained via the process including electrophilic palladation,acetalization,transmetalation and reductive elimination.However,under certain conditions,N,O-spiroketals could further coordinate with Pd???to realize the aromatization process access to 5-aryl-2-aminoalkyl furan compounds.By screening the reaction conditions,we finally synthesised N,O-spiroketals with KF as the suitable additive and obtained 5-aryl-2-aminoalkyl furan compounds with KOAc as the suitable additive.2.Pd???/O₂ catalyzed arylation of?-furan-propionic acidIn this chapter,we firstly reviewed the research progress of direct arylation occurring on furan derivatives using arylboronic acid as an aromatic source,and then according to the reason for the formation of 5-aryl-2-aminoalkyl furan compounds via the arylation of?-aminoalkyl furan derivatives,we realized the arylation of?-furan-propionic acid with arylboronic acids in a palladium-catalyzed aerobic oxidative system.