Studies On The Heteropoly Acid Catalyzed Propargyl Substitution Reaction

Propargyl compound has a unique structure and reactivity, which draws moreattention in recent years as a reaction intermediate. Carbon-carbon triple bond of thepropargyl-based compound can be easily converted into other functional groups; itcan also be activated by the metal complex at propargyl position, in order to facilitatethe attack of nucleophiles. This makes the propargyl substitution reaction plays animportant role in organic synthesis.Heteropoly acid (abbreviated as HPA) is composed of hetero atoms (such as P,Si, Fe, Co, etc.), and multi-atoms (such as Mo, W, V, Nb, Ta, etc.) according to acertain structure through the coordination of the oxygen atom, with high catalyticactivity. Heteropoly acid has good stability, can be used for both homogeneous andheterogeneous reaction, even as phase transfer catalyst, no pollution to theenvironment, is a kind of promising green catalyst.Propargylic Sulfides compounds can be widely used as an important intermediatein organic synthesis. It can construct a series of important natural product andbiological active compounds through catalytic cyclization. Therefore, low carbon,environmentally friendly catalyst for highly efficient synthesis of propargyl propylsulfide compounds is of great significance.The thesis describes the heteropoly acid catalyzed propargyl substitution reaction,forming (1,3-diphenylprop-2-ynyl)(p-tolyl) sulfide compounds. Progress onpropargyl propyl substitution reaction in recent years were also reviewed. Theexperimental results shows that the phosphotungstic acid can be used for nucleophilicsubstitution reaction of propargylic alcohols and thiols, reaction time directlyinfluence the final yield. The optimal reaction conditions are obtained:50%PWA (w=4%)，DCE，80℃，6h. This method is simple in operation, low carbon environmentalprotection, high efficiency, good tolerance to substrate. For the benzene ringsubstituted propargyl alcohol, either electron-withdrawing or weak electron-donatinggroups, the product can be obtained in moderate to good yields. For the benzene ringsubstituted thiophenols, this reaction system can be applicable, and the electronic effect is not obvious. The aliphatic propargyl alcohol can also be used in thissubstitution reaction system, to obtain the corresponding products in moderate yield.However, for the heterocyclic propargyl alcohol, this reaction system is notapplicable.