Study On Carbonylation Catalyzed By Bidentate Phosphine(Nitrogen)Ligands-Modified MCM-41-Supported Palladium Complexes

Over the past decades,transition metal-catalyzed reactions have been widely used in organic synthesis,among them,palladium is the most widely used catalyst.In this dissertation,we mainly investigate the application of the bidentate phosphine?nitrogen?-modified mesoporous material MCM-41-supported palladium complexes in the palladium-catalyzed carbonylation reactions.The dissertation consists of four parts as follows:1?A highly efficient and practical heterogeneous palladium-catalyzed carbonylative coupling of 2-iodoanilines with aryl iodides has been developed that occurs smoothly in toluene at 110oC with N,N-diisopropylethylamine as base under 5 bar of carbon monoxide and offers a general and powerful tool for the construction of various valuable 2-arylbenzoxazinones with excellent atom-economy,high functional group tolerance,good to high yield,and easy recyclability of the palladium catalyst.The reaction is the first example of heterogeneous palladium-catalyzed carbonylative coupling for the preparation of diverse 2-arylbenzoxazinones from commercially easily available 2-iodoanilines and aryl iodides.2?A highly efficient,green palladium-catalyzed cyclocarbonylation of 2-iodo-anilines with acyl chlorides has been developed that proceeds smoothly in a biomass-derived solvent 2-methyltetrahydrofuran?2-MeTHF?with N,N-diisopropylethylamine?DiPEA?as base at 100oC under 20 bar of carbon monoxide using an 2-aminoethyl-amino-modified MCM-41-anchored palladium acetate complex[2N-MCM-41-Pd?OAc?₂]as a heterogeneous catalyst,yielding a wide variety of 2-substituted4H-3,1-benzoxazin-4-one derivatives in good to excellent yield.This supported palladium catalyst could be facilely obtained by a two-step procedure from easily available starting materials and readily recovered via a simple filtration process and recycled at least 8 times without any apparent decrease in catalytic efficiency.The developed methodology not only avoids the use of toxic solvents such as THF and DMF,but also solves the basic problem of expensive palladium catalyst recovery and reuse,and prevents effectively palladium contamination of the desired product.3?A convenient,efficient and practical heterogeneous palladium-catalyzed carbonylative Sonogashira coupling of aryl iodides with terminal alkynes under CO gas-free conditions has been developed by using an MCM-41-supported bidentate phosphine palladium acetate complex as catalyst.Here,formic acid was used as the CO source with dicyclohexylcarbodiimide?DCC?as the activator and a wide variety of alkynyl ketones were generated in moderate to high yields.This heterogeneous palladium catalyst can be easily recovered via a simple filtration process and recycled up to 8 times without apparent loss of activity.