Alkynes Carbonhalogenation Catalyzed By Pd/Cu With Furan As A Nucleophile

Furan derivatives are ubiquitous in nature and are a cheap and readily available biomass resource.Due to its low aromaticity,furans exhibit the reactivity of functional groups such as olefins,enol ethers,1,4-dicarbonyl compounds,and conjugated dienes.Some high value-added chemical products can be obtained through the conversion of furans.On the other hand,alkynes are also active compounds.Alkyne triple bonds are prone to nucleophilic addition reaction with the presence of transition metal,in which nucleopalladation of alkynes has been widely reported in literatures.Based on the above background,we combined active furan compounds with alkynes and uses simple furan-alkyne compounds to synthesize heterocyclic compounds with potential application value under room temperature.The details are as follows:The second chapter mainly studies the synthesis of a series of chalcone derivatives from furan-yne catalyzed by Pd/Cu,undergoing intramolecular furan palladiumation of alkyne,rearrangement of furanoxonium ions,and reduction elimination of alkenyl palladium.This reaction is the first example of an alkynes' nucleophilic addition reaction with furan as a nucleophile.Simultaneously,the reaction creates the C-C bond through the furan-palladization of alkynes and the subsequent elimination of the alkenyl-palladium intermediate eliminating to construct C-X bond,unlike the way in which the common alkynes halo-palladization builds the C-X bond and the subsequent olefin insertion builds the C-C bond.We adopted cheap palladium and copper as catalysts and air as a green oxidant to develop a new strategy for the efficient conversion of furans.The reaction conditions of the method are mild,the applicable range of the substrate is good,and the obtained chalcone derivatives have good biological activity.