Synthesis Of ?-aryl-3-pyrroline And Indole Substituted Spirochroman Heterocyclic Compounds

As a branch of organic compounds,heterocyclic compounds are widely distributed in many natural products.Because of their special pharmacology,physiological activity and unique material functionality,they occupy an important position in the pharmaceutical industries,agro-chemistry,multifunctional materials,and fine chemical industries.As a result,the modification and construction of heterocyclic compounds has been a hot topic in organic synthetic chemistry.Based on a comprehensive investigation of nitrogen-containing and oxygen-containing heterocyclic compounds,this dissertation developed two new methods for the facile construction of heterocyclic compounds including?-aryl-3-pyrrolines and spirochromanes.There are three chapters will be elaborated in detail in this dissertation:The first chapter of this paper mainly introduced the research progress of?-aryl-3-pyrrolines/pyrrolidines and chromanes.In the second chapter,a sulfur-directed palladium-catalyzed C(sp~3)-H?-arylation of 3-pyrrolines has been achieved.The arylation reactions using arylboronic acids as coupling partners provided a variety of 2-aryl-3-pyrolines in moderate to good yields.Moreover,the?-arylated products could be readily transformed into various synthetically useful 3-pyrroline and pyrrolidine derivatives,especially polysubstituted pyrrolidines.This work provides a practical and flexible method for constructing multi-substituted pyrrolidines,which has certain synthetic application value.In the third chapter,an efficient Friedel-Crafts alkylation between indoles and spiropyrans catalyzed by Br(?)nsted acid has been explored.Utilizing the characteristic of spiropyran,which can isomerize to the colored merocyanine(MC)form from the colorless spirocyclic(SP)form upon external stimuli(eg.light or pH),we have successfully realized the efficient splicing of two important heterocyclic skeletons including indoles and spiropyrans.It should be pointed out that the merocyanine intermediate which contains highly active?,?-unsaturated ketimine structure is the key to the reaction.This work is simple and convenient.It provides a convenient and efficient way for the synthesis of spirochroman compounds.