Portal de Periódicos da CAPES

Pentamethylcyclopentadienyl-rhodium and -iridium complexes. Part 27. Catalysed oxygenation reactions; tetrahydrofuran to γ-butyrolactone

1981; Science Press; Volume: 10; Issue: 2 Linguagem: Inglês

10.1016/0304-5102(81)85009-2

1873-3131

Koichi Hirai, Andrew Nutton, Peter M. Maitlis,

Lanthanide and Transition Metal Complexes

The tri-μ-hydroxo-complex [Rh2(C5Me5)2(OH)3]Cl·4H2O(1) catalyses the oxygenation of tetrahydrofuran to γ-butyrolactone in the presence of small amounts of water. Peroxides cause a similar reaction. Complex (1) also catalyses the oxygenation of Ph3P to Ph3PO; however, (EtO)3P is not oxidised but is into [(RhC5Me5) (EtO)3P3]2+. Complex (1) is itself oxidised by to give initially a paramagnetic species with an ESR spectrum similar to that of Rh(II)—O2 complexes, which is tentatively identified as [RhII(C5Me5)(O2)X], and finally to acetic acid, acetate, and CO2. Solids containing acetate can be isolated from this reaction that are similar to materials obtained by the air-oxidation of (1) in isopropanol and base. The mechanisms of these oxidation reactions are discussed.