Research Of Mizoroki-heck Coupling Reactions Of Arenediazonium Tetrafluoroborate Salts Catalyzed By Novo-Catalyst Of Palladium Nanoparticles

As a most effective method in carbon-carbon bond formation,The Mizoroki-Heck cross-coupling reaction is being extensive used in modern organic synthesis and play an extremely important role in the synthesis of many complex organic molecules and natural products.Therefore,extensive attentions have been focused on this reactions for a long time.The palladium-catalyzed Heck coupling reaction holds a more and more prominent position in synthesis due to its exceptional versatility.A novel air and moisture-stable nano palladium catalyst,which has been successfully applied on couplings of arylboronic acids with aryl halides and arenediazonium tetrafluoroborate salts by our group,was made by "one-pot"method in this paper.And then,this nano palladium catalyst was reported for the first time to show excellent catalytic effection in the Heck coupling reactions of arenediazonium tetrafluoroborate salts with olefins.The reaction conditions were optimized and the products were examined by TLC,IR,1H NMR.The optimal reaction conditions:olefin 0.2 mmol as standard substrate,benzendiazonium tetrafluoroborate salts 1.5 equiv,nano-palladium 2.0 mol%as the catalyst,reaction temperature 25 ?,EtOH 1.0 mL as solvent.Next,a variety of arenediazonium tetrafluoroborate salts and olefins were examined for the cross-coupling reactions using optimized conditions.It was shown that whatever the electronic and steric nature of the cross-coupling partners,most of the reactions gave products in good to excellent yields under mild conditions.In addition,it was found that 2,6-dichlorobenzenediazonium tetrafluoroborate was also a good substrate providing 90%yield in terms of methyl acrylate.The products of Heck reaction can be used to prepare compounds with different functional groups.The advantages of this method include employing easily available,air-and waterstable nano-palladium as catalyst.Therefore,this research has a great usefulness in synthetic chemistry,experimentally operational easy,mild conditions almost no side reaction.