Palladium Catalyzed Addtion Reaction Of α-Nitroesters With Alkynes

Many nucleophiles and allyl compounds can react under Palladium catalyst.It can gain the product of allylation.We name this reaction as Tsuji-Trost. This reaction proceed through a common reaction mechanism,via the formation of theπ-allyl palladium complex and subsequent nucleophilic attack to complete the allylation process. The reaction usually has two characteristics:(1) Relatively mild reaction conditions,this reaction can proceed very well under no harsh conditions.(2)The substrates of the reaction have a wide choice,We can build C-C,C-N,C-O bond through this reaction. So this reaction has a very wide range of application in modern organic synthesis. Propargyl compound is a important intermediate in modern organic synthesis. The isomerization of alkynes to allenes by palladium hydride complexes is also well known in the chemical literature. Yamamoto first discovered that propargyl compounds and nucleophiles can react to produce the praduct of allylation. He make use of methylmalononitrile and 1-phenyl-l-propyne as the substrate, Pd(PPhs)4 as catalyst,and acetic acid (50 mol%) in dioxane at 100℃to give the adduct as a sole product in 99% yield.This reaction compare with Tsuji-Trost reaction.Although the products of the two reactions are allylation products, the reaction has two distinct advantages:(1) The reaction does not require a stoichiometric amount of base,It can react very well only in catalytic amount of palladium reagents.(2) The reaction does not produce leaving group, high atom economy. In this text, we supposed that we can choose some alkynes and a-nitroesters,which are catalyzed by palladium.In this way,we can enable an eco-chemical process to be carried out without liberating leaving groups. The main contents of this thesis are as follows:(1) Some features of the palladium catalyst and its common coupling reaction in application aspects was introduced.(2) We describes that the basic situation of allyl compounds and nucleophiles react as allylation under palladium catalyst,we also explain the mechanism of the reaction. the reactions in organic synthesis are introduced.(3) We choose 1-phenyl-1-propyne and Ethyl 2-nitrate as the basic substrate to optimize the reaction conditions,and explore the palladium reagents, solvents and additives on the reaction, and the results were discussed to arrive at the optimal reaction conditions of the reaction. (4) We desigh different alkynes andα-nitroesters to synthesize eleven products. The structures of all these compounds were characterized by 1HNMR, elemental analysis and mass spectra.