Synthesis Of Conjugated Diene And Pyridine Salt Based On Carbon Carbon Unsaturated Bond

Alkenes and alkynes have been widely used in the synthesis of various drug molecules and natural compounds because of their unsaturated carbon carbon bonds,which can efficiently construct carbon carbon and carbon heterobonds.How to realize the selective functionalization of alkene and alkynes in green and high efficiency has been a hot topic in organic synthesis chemistry.Conjugated dienes can undergo cycloaddition reactions with high chemical selectivity and are widely used in the synthesis of cyclic compounds;pyridinium salts,as important intermediates for the synthesis of natural products and bioactive compounds,also have important applications in industrial synthesis.In the past few decades,a series of methods have been developed for the synthesis of these two compounds.However,due to the problems of economy and environmental protection,this series of methods can not be widely used.In this regard,we designed the corresponding raw materials according to the target products,and then synthesized conjugated dienes and pyridinium salts by self reaction under simple and mild conditions.The main contents are as follows:1.A cascade reaction of desulfonation and dehydrogenation of（Z）c6-vinylsulfonylphenanthridine promoted by potassium TERT butoxide has been developed for the selective synthesis of 1,3-conjugated dienes.It is a novel and effective method for the synthesis of phenanthridine functionalized 1,3-conjugated dienes.In addition,1,3-conjugated dienes were synthesized by[4+2]cycloaddition reaction with fumaronitriles and arylalkynes.2.We have realized a new and efficient mothed for synthesis of functionalized pyridinium salts via Cu（OAc）₂ promoted domino reactions from alkynyl substituted benzenesulfonohydrazides.This approach provides a simple and mild avenue to functionalized pyridinium salts by used Cu（OAc）₂ as promoter,Na₂S₂O₄ as additives,toluene as solvent,in 80℃oil bathing for 12 hours.Furthermore,this reaction has a broad substrate scope and shows moderate to high yields.