Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-III-35CATALYTIC OXIDATION OF ORGANIC SUBSTRATES WITHHYDROGEN PEROXIDE IN TWO-PHASE SYSTEMSZ.P. Pai 1 , A.G. Tolstikov 1 , P.V. Berdnikova 1 , T.B. Khlebnikova 1 , O.N. Roor 1 ,N.V. Selivanova 1 , N.K. Gusarova 2 , S.F. Malysheva 2 , N.I. Ivanova 2 , B.A. Trofimov 21 Boreskov Institute of Catalysis SB RAS, 5 Lavrentieva Prospekt, 630090 Novosibirsk, Russia,Fax: +7(383)3308056, E-mail: zpai@catalysis.ru2 Favorsky Irkutsk Institute of Chemistry, Siberian Branch of RAS, 1 Favorsky Street,664033 Irkutsk, Russia, Fax +7(3952) 419346; E-mail: gusarova@irioch.irk.ruIn our earlier works [1], we synthesized and characterized the catalysts based on thetetra(oxodiperoxotungsto)phosphate ({PO 4 [WO(O 2 ) 2 ] 4 } 3– with quaternary ammonium cations,such as [(n-Bu) 4 N] + , [C 5 H 5 N(n-C 16 H 33 )] + , and [MeN(n-C 8 H 17 ) 3 ] + . Such catalytic systemsprovide efficient synthesis of a number of important aliphatic and aromatic epoxides as wellas mono- and dicarboxylic acids by direct oxidation of different organic substrates withhydrogen peroxide in two-phase systems [2].Since tungstate peroxocomplexes have a significant place in the organic substrateoxidations, the present study was aimed at in situ synthesis of oxoperoxotungstates containingorganic ligands – tertiary phosphine oxides and testing of their catalytic activity in the organicsubstrate oxidation reactions (cyclooctene, benzyl alcohol).Tertiary phosphine oxide ligands (tris[2-(2-pyridinyl)etnyl]phosphine oxide, 1-diphenyl-1-[2-(1-ethylimidazol)-1-hydroxymethyl]phosphine oxide, 1-diphenyl-1-[2-(1-vinylimidazol)-1-hydroxymethyl]phosphine oxide) synthesized by the method described elsewhere [3].Oxidation of benzyl alcohol was performed in a two-phase systems (organic phase - aqueousphase) at 80 °C upon varied [W] / [L], [Sub] / [Cat] and [Ox] / [Sub] ratios. Epoxidation ofcyclooctene was performed at 60 °C in a two-phase system.Thus, the experiments showed that the bifunctional homogeneous metal complex catalystsbased on the peroxopolyoxotungstatophosphates combined with organic ligands such astertiary phosphine oxides can be recommended for the selective oxidation of organicsubstrates with hydrogen peroxide in two-phase systems.The oxidation reactions of benzyl alcohol and cyclooctene were used to illustrate theprospects of tungstatophosphoric acid and tris[2-(2-pyridinyl)etnyl]phosphine oxide or1-diphenyl-1-[2-(1-ethylimidazol)-1-hydroxymethyl]phosphine oxide as precursors ofperoxopolyoxotungstate catalysts. It was established that the presence of groups with anunsaturated C=C bond in the phosphine oxide molecule adversely affect both the conversiondegree and selectivity of the oxidation reactions.369