The Radical Reaction Of Allenes And The Nucleophilic Addition Reaction Of Electron-Deficient Allenes

In this dissertation, the Mn(OAc)₃-mediated radical reaction of allenes with dimethyl manolate and ethyl cyanoacetate; the hydrochalcogenation reaction of allenyl diphenyl phosphine oxides and allenyl sulfoxides; and the carbocupration of acetylenic phosphine oxides were investigated.Firstly, the Mn(OAc)₃-mediated radical reaction of allenes with dimethyl manolate and ethyl cyanoacetate was investigated. (1) the radical intermediates, generated from dimethyl malonate and ethyl cyanoacetate in the present of Mn(OAc)₃, take a intermolecular central attack to 1-alkyl phenylallenes to give addition intermediates, which were coverted to 5-alkyl-4-methyl-2-oxo-5-phenyl-2,5-dihydro-furan-3-carbo-xylic acid methyl ester ( or carbonitrile) finally; (2) the radical intermediates, generated from dimethyl malonate in the present of Mn(OAc)₃, take a intermolecular central attack to arylallenes to give addition intermediates, which were coverted to 2-(1-Methyl-2-oxo-2-aryl-ethylidene)-malonic acid dimethyl ester finally; (3) by building the unite of manolate and allenyl into one molecule, the Mn(OAc)₃-mediated intramolecular reaction was also investigated.Secondly, the synthesis of β-oganochalcogenyl allyl phosphine oxides, β-oganochalcogenyl allyl phenylsulfoxides and their application in organic synthesis was investigated. Through the regioselective addition of organyl thiolate, selenolate or tellurolate anions to allenyl phosphine oxides and allenyl sulfoxides, the β-oganochalcogenyl allyl phosphine oxides and β-oganochalcogenyl allyl phenylsulfoxides were obtained in good yields. The coupling reaction of β-phenyltelluro allyl phosphine oxide and β- phenyltelluro allyl sulfoxide with terminal alkynes were also studied at the same time.Thirdly, carbocupration of acetylenic phosphine oxide was investigated. The vinylcopper intermediates stabilized by the a-diphenyl phosphine oxide react with electrophiles, such as I₂, PhSeBr, PhTeI and allyl bromide to give a-functionalized vinyl phosphine oxides and 1,4-dienes.