Mechanistics studies on the cobalt(II) Schiff base catalyzed oxidation of olefins by O/sub 2/

Journal Article · Tue Jan 20 23:00:00 EST 1987 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00236a014· OSTI ID:6970339

Hamilton, D E; Drago, R S; Zombeck, A

The cobalt complex (bis(salicylidene-..gamma..-iminopropyl)methylamine)cobalt(II), CoSMDPT, has been shown to catalytically oxidize olefins in the presence of dioxygen or hydrogen peroxide. When terminal olefins are oxidized, the methyl ketone and corresponding secondary alcohol are produced selectively. Internal as well as terminal olefins are oxidized. The most common pathway for the oxidation of olefins catalyzed by first-row transition metals-autoxidation-has been ruled out in this system. A Wacker-type mechanism, oxidation by peracids, and mechanisms involving the formation of peroxymetallocycles have also been ruled out. A new mechanism for O/sub 2/ oxidations is proposed which involves oxidation of the primary alcohol solvent by CoSMDPT to produce the corresponding aldehyde and hydrogen peroxide. Reaction of hydrogen peroxide with CoSMDPT occurs to form a cobalt hydroperoxide, which can be viewed as a stabilized hydroperoxy radical which has spin paired with the d/sub z/sup 2// electron of CoSMDPT. The cobalt hydroperoxide then adds to the olefin double bond, leading to formation of an alkyl hydroperoxide. Haber-Weiss decomposition of this alkyl hydroperoxide by CoSMDPT produces the observed ketone and alcohol products. Deactivation of the catalyst is due to oxidation of the ligand system of the cobalt complex as well as formation of a ..mu..-peroxo-dicobalt complex.

• Research Organization: Univ. of Florida, Gainesville
• OSTI ID: 6970339
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 109:2; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ALCOHOLS
ALKENES
AMINES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL BONDS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COBALT COMPLEXES
COMPLEXES
DATA
DOUBLE BONDS
ELEMENTS
EXPERIMENTAL DATA
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
HYDROXY COMPOUNDS
INFORMATION
KETONES
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDATION
OXYGEN
OXYGEN COMPOUNDS
PEROXIDES
SPECTRA
SPECTROSCOPY
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
VISIBLE SPECTRA