TRANSITION METAL-CATALYZED FANCTIONALIZATION REACTION OF ALKANES IN SUPERCRITICAL FLUID

(1)The new catalytic system has been examined for the partial oxidation of methane in liquid phase。It was found that the vanadium containing heteropolyacids/K2S2O8/(CF3CO)2O/CF3COOH catalyst system converts methane to methyl trifluoroacetate along with a trace amount of methyl acetate in a 95%yield based on methane.The activation energy of the reaction was estimated to be 27.9kcal/mol.(2)The VO(Acac)2(acac=2，4-pentanedionato)catalyst in the presence of K2S2O8and CF3COOH has been found to efficiently transform methane and CO to acetic acid selectively.The reaction of Methane(5atm)with CO(20atm)at80 I D1°I D1C for 20h gives acetic acid in93%yield based on methane.Other vanadium compounds such as V2O3，V2O5，and NaVO3 and various vanajium-containing heteropolyacids such as H5PV2Mo10O40，H4PVW11O40，and H5SiVW11O40also work as catalysts.(3)As a catalyst of the above two reactions，VO(OCOCF3)3complex was isolated。This new catalytic system has been examined for the carboxylation and oxidation of methane in supercritical carbon dioxide.It was found that this vanadium complex is insoluble to supercritical carbon dioxide and has no catalytic activity affording no product.(4)Cobalt(II)acetate(Co(OAc)2)has been found to be an efficient catalyst for the carboxylation reaction of saturated hydrocarbons with CO to yield the corresponding carboxylic acids in high yields in the presence of K2S2O8 and CF3COOH..About#china_person0#.55conversion of propane is obtained in this reaction。The activation parameters of the reaction of propane have been determined by Arrhenius and Eyring plots.

(1) The new catalytic system has been examined for the partial oxidation of methane in liquid phase. It was found that the vanadium containing heteropolyacids/K2S2O8/(CF3CO)2O/CF3COOH catalyst system converts methane to methyl trifluoroacetate along with a trace amount of methyl acetate in a 95% yield based on methane. The activation energy of the reaction was estimated to be 27.9 kcal/mol.(2) The VO(acac)2(acac=2,4-pentanedionato) catalyst in the presence of K2S2O8 and CF3COOH has been found to efficiently transform methane and CO to acetic acid selectively. The reaction of Methane (5 atm) with CO (20 atm) at 80ィイD1゜ィエD1C for 20 h gives acetic acid in 93% yield based on methane. Other vanadium compounds such as V2O3, V2O5, and NaVO3 and various vanajium-containing heteropolyacids such as H5PV2Mo10O40, H4PVW11O40, and H5SiVW11O40 also work as catalysts.(3) As a catalyst of the above two reactions, VO(OCOCF3)3 complex was isolated. This new catalytic system has been examined for the carboxylation and oxidation of methane in supercritical carbon dioxide. It was found that this vanadium complex is insoluble to supercritical carbon dioxide and has no catalytic activity affording no product.(4) Cobalt (II) acetate (Co(OAc)2) has been found to be an efficient catalyst for the carboxylation reaction of saturated hydrocarbons with CO to yield the corresponding carboxylic acids in high yields in the presence of K2S2O8 and CF3COOH. About 89.55 conversion of propane is obtained in this reaction. The activation parameters of the reaction of propane have been determined by Arrhenius and Eyring plots.