Applications Of Palladium-Catalyzed Isocyanide Insertion Reaction In The Synthesis Of Thiochromenones Compounds

Object:In the past decades,transition metal-catalyzed reactions involving isocyanide insertion as C1 building blocks instead of carbon monoxide,has been attracting more attention on the basis of the application of the multicomponent reactions.To investigate whether isocyanides could be utilized as carbonyl source to synthesize thiochromenones from the available materials,which will expand their applications in synthesize potentially bioactive moiety.Methods:By screening the factors that affected the reaction,for instance solvent,catalyst,ligand,base,etc.,to find the optimal conditions for carbonylative synthesis of thiochromenones via palladium-catalyzed isocyanide insertion.Results:The optimal conditions for carbonylative synthesis of thiochromenones via palladium-catalyzed isocyanide insertion reaction are 1-bromo-2-fluorobenzene,phenylacetylene,tert-buty1 isocyanide,Na2S·9H2O,Pd(OAc)2,DPEPhos,Cs2CO3 and anhydrous DMF,oxalic acid/tetrahydrofuran.Conclusion:In this paper,we have overcame the problems associated with the irreversible poisoning of transition-metal catalyst by sulfide anions and addressed the challenges of the potential side reaction with sulfide or its hydrate,and achieved carbonylative synthesis of thiochromenones via palladium-catalyzed isocyanide insertion.