Application Of In Situ Propargyl-allenyl Isomerization For The Construction Of Heterocyclic Compounds

Heterocyclic compounds are widely existing in nature. Natural products and drugs have numerous heterocyclic skeleton structures; Heterocyclic compounds are applied to human lives everywhere. Therefore, construction of heterocyclic compounds has been an important topic for chemists. This thesis starts from the propargyl-allenyl isomerization, followed by other kinds of heterocyclic reaction, providing efficient methods for construction of heterocyclic compounds.This thesis is divided into two parts:The first part:Synthesis of 2,3-dihydrofurans via the sequence of propargyl-allenyl isomerization and Alder-ene reaction.In the second chapter, we chose propargyl ether as the substrate, the substrate occurs propargyl-allenyl isomerization to form intermediate, followed by Alder-ene reaction to offer product. The method, with high yield, is a good protocol for preparation of 2,3-dihydrofurans.The second part:Synthesis of benzothiophenyl and thiophenyl ketones/aldehyde/ phosphine oxides via ?-sulfonium carbanion.In the third chapter, we use sulfide as the substrate, which occur propargyl-allenyl isomerization, followed by sulfur addition reaction, [3,3]-? rearrangement to get benzothiophenyl and thiophenyl compounds.