Study On The Synthesis Of Heterocyclic Compound By Palladium Or Silver-Catalyzed Reaction

Heterocyclic compounds are widely existed in the natural products,which are extensively applied in the pharmaceutical industry owing to its biological activities and pharmacological activities.Therefore,it would be attracted much attention of the organic chemists to find an effecient and green route to synthesize heterocyclic compounds.In the past two decades,although the construction of the heterocyclic compounds by transition metal-catalyzed occupied an important role subject to the limition of the harsh condition and the scope of substrates,it was still desired to develop the new strategy to synthesize the above compounds.In this paper,we have reported the Pd(OAc)2/S=PPh3 activiated the gem-dichloroalkenes to construct the 3-arylchromones.Next,AgOAc triggered the phos-central radical was applied to prepare the polycyclic compounds,and enriched the routes of heterocyclic compounds.The mechanism is thoroughly and meticulously investigated as well,which provides the insight for the synthesis of heterocyclic compounds with the catalytic oxidation.The essay mainly consists of the following two parts: 1.The palladium catalyzed gem-dichloroalkenes to synthesize 3-arylchromonesThe Pd-catalyzed regioselectively intramolecular nucleophilic substitution of gem-dichloroalkenes derivatives with salicylaldehydes leading to synthesis of 3-arylchromones has been developed.gem-Dichloroalkenes is the powerful and versatile building block to construct the corresponding chromones in moderate to excellent yields.The role of Pd(OAc)2/triphenylphosphine sulfide is critical as it could activate the gem-dichloroalkenes and undergo the nucleophilic substitution by salicylaldehydes with the aid of base.2.The synthesis of nitrogen polycyclic aromatic compounds by silver-triggered radical processSubstituted indoles forming the core skeletons are widely found in pharmaceuticals and naturally occurring alkaloids.Considering the diphenylphosphine easily oxidized to form Phos-central free radical,AgOAc was applied to be a relatively cheap and nontoxic catalyst of olefin phosphate reaction to synthesis nitrogen polycylic aromatic compounds.In this work,different substituted indoles have been prepared according to the literature.Based on the characteristic of these substrates,they are well tolareted for the intramolecular cyclization reaction to synthesis nitrogen polycylic aromatic compounds under the mild condition.In addition,AgOAc/O2 is an efficient and simple system with no additional ligrand,which provides a new route for a variety of heterocyclic compounds.