Ruthenium-Catalyzed Isomerization of Allylic Alcohols: Oxidation State Determines Resistance Against Diene Inhibition

Autor: Huub Kooijman, Jeroen W. Sprengers, Elisabeth Bouwman, Robert C. van der Drift, Eite Drent, Wilhelmus P. Mul, Anthony L. Spek
Rok vydání: 2002
Předmět:
Zdroj: European Journal of Inorganic Chemistry. 2002:2147-2155
ISSN: 1099-0682
1434-1948
Popis: The novel complex mer-[RuCl3(dmso)(phen)] (1) has been prepared and characterized by X-ray diffraction. The ruthenium center is in a distorted octahedral environment with the three chloride ions coordinated in a mer-fashion and an S-bonded dmso ligand trans to one of the phen nitrogen atoms. Electrochemical experiments show two reversible waves in acetonitrile solution, corresponding to the couples RuIII/II (0.11 V) and Ru IV/III (1.73 V). The analogous Ru II complex cis,cis-[RuCl2(dmso)2(phen)] (2) shows one reversible wave at 1.08 V, corresponding to the Ru III/II couple. Both complexes exhibit high catalytic activity in the isomerization of 3-buten-2-ol to butanone. The initial turnover frequency (TOF) for 1 in diglyme/water at 130 °C is 295 h −1 with a firstorder kini of 0.6 h −1 , while 2 reaches an initial TOF of 260 h −1 and a kini of 0.5 h −1 . A cumulative turnover number (TON) of 1025 has been obtained with 1 as a catalyst precursor. The activity of 1 and 2 has been compared to that of in situ mixtures with both Ru III and Ru II precursors. All Ru II complexes are deactivated before 100% conversion has been attained.
Databáze: OpenAIRE
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