Synthesis Of 1,3-Disubstituted-1,3-Dihydroisobenzofurans And Cyclohexenone-Fused Isochromans Promoted By Tin Powder

Among many natural products and drug molecules,heterocyclic compounds are the most common structural units due to their wide biological activities,and thus play a very important role in organic synthesis.As important oxygen-containing heterocyclic compounds,1,3-dihydroisobenzofuran and cyclohexenone-fused isochromans are widely present in natural products with biological activity and useful drug molecules.Therefore,it is particularly important to explore a simple and efficient method to synthesize 1,3-dihydroisobenzofurans and cyclohexenone-fused isochromans.On the other hand,organotin reagent can be widely used in organic synthesis because of its stability to water and oxygen,good thermal stability,strong functional group tolerance and high selectivity.However,its development is hindered by its complex preparation,toxicity,volatilization and low utilization of atoms.It was not until 1981 that Mukaiyama explored and found that under the promotion of tin powder,allyl bromide or iodine could generate in situ allyl tin reagent and participate in the reaction at the same time,realizing the "one-pot" method reaction under the promotion of tin powder for the first time.This method not only effectively avoids the disadvantages of organotin reagent,but also preserves the advantages of organotin reagent.Accordingly,we studied the synthesis of 1,3-disubstituted-1,3-dihydroisobenzofuran and cyclohexenone-fused isochromans compounds facilitated by tin powder.This paper is mainly composed of the following three chapters:The chapter one: The Research Progress of 1,3-Dihydroisobenzofurans compoundsIn this chapter,we mainly summarize the classification of 1,3-dihydroisobenzofuran compounds and review the synthesis methods.The chapter two: Synthesis of 1,3-Disubstituted 1,3-Dihydroisobenzofurans by Tin Powder Promoted Tandem Nucleophilic/Oxa-Michael Addition of o-Formylchalcone with Ally bromidesIn this chapter,we develop the tandem nucleophilic addition/Oxa-Michael addition between allyl bromide and o-formylchalcone promoted by tin powder.By this method,1,3-disubstituted-1,3-dihydroisobenzofuran compounds were synthesized by "one-pot" method,and an effective method for the synthesis of these compounds was established,Which is simple to operate,short reaction time,good functional group tolerance,and excellent yield.The chapter three: Synthesis of Cyclohexenone-Fused Isochromans by Tin powder Promoted Tandem Nucleophilic/Oxa-Michael Addition of 1’-methoxy-4’-oxy-1’,4’-dihydrogen-[1,1’-biphenyl]-2-formaldehyde with Allyl bromidesIn this chapter,a simple and efficient three-component "one-pot" tandem nucleophilic addition /Oxa-Michael reaction is developed.promoted by tin powder,a simple and efficient method for the synthesis of cyclohexenone isochromic compounds was prepared by the reaction of 1 ’-methoxy-4’-oxy-1 ’,4 ’-dihydrogen-[1,1’-biphenyl]-2-formaldehyde with allyl bromide.This method is easy to obtain raw materials,easy to operate and yield in medium to good.