Hydrogen Peroxide Oxidation Catalyzed by Heteropoly Acids Combined with Cetylpyridinium Chloride: Epoxidation of Olefins and Allylic Alcohols, Ketonization of Alcohols and Diols, and Oxidative Cleavage of 1,2-Diols and Olefins

Article abstract of DOI:10.1021/jo00250a032

A general and versatile oxidation catalyst has been developed by using hydrogen peroxide as the oxidant.Olefins and allylic alcohols were epoxidized with commercially available hydrogen peroxide (30-35percent H2O2) using a combination of Mo- or W-based heteropoly acids, H3PMo12O40 (MPA) or H3PW12O40 (WPA), with an appropriate ammonium salt such as cetylpyridinium chloride (CPC), under two-phase conditions using chloroform as the solvent (Tables I and II).The tris(cetylpyridinium) 12-tungtophosphate (CWP), +(CH2)15CH3>3(PW12O40)^3-, prepared independently from WPA and 3 equiv of CPC, catalyzes the efficient ketonization of the secondary hydroxy group of alcohols and diols with H2O2 under homogeneous conditions using tert-butyl alcohol as the solvent (Table III).Under the same conditions, oxidative cleavage of vic-diols was successfully conducted by the CWP-H2O2 system to give carboxylic acids in good yields (Table IV).This catalyst-oxidant system was also efficient for the oxidative cleavage of carbon-carbon double bonds of olefins which provides a new valuable conversion of olefins to carboxylic acids (Table V).