Oxone, Potassium peroxomonosulfate
The composition of the oxidizing agent Oxone® is 2KHSO5.KHSO4.K2SO4. The active component potassium monopersulfate (KHSO5, potassium peroxomonosulfate) is a salt from the Caro´s acid H2SO5.
The use of Oxone has increased rapidly. Reasons for this are the stability, the simple handling, the non-toxic nature, the versatility of the reagent and the low costs.
B. R. Travis, M. Sivakumar, G. O. Hollist, B. Borhan, Org. Lett., 2003, 5, 1031-1034. DOI
As long as Oxone is stored under dry and cool conditions, it loses about 1% activity per month under release of oxygen and heat. Decomposition to SO2 and SO3 takes place under the influence of heat (starting at 300°C).
Acidic, aqueous solutions of the pure reagent in distilled water are relatively stable. The stability reaches a minimum at pH 9, where the mono anion (HSO5-) has the same concentration as the dianion (SO52-). Iron, cobalt, nickel, copper, manganese and further transition metals can catalyze the decay of Oxone in solution.
The following secondary reactions should be avoided: Halides can be oxidized to halogens (e.g. chloride to chlorine), cyanides react with Oxone under release of hydrogen cyanide, "heavy" transition metals (Cu, Mn, Co, Ni) and their salts lead to the decomposition of Oxone under release of oxygen.
Recent Literature
Highly efficient, mild, and simple protocols allow the oxidation of aldehydes to
carboxylic acids and esters utilizing Oxone as the sole oxidant. These reactions
may prove to be valuable alternatives to traditional metal-mediated oxidations.
B. R. Travis, M. Sivakumar, G. O. Hollist, B. Borhan, Org. Lett.,
2003, 5, 1031-1034.
B. R. Travis, M. Sivakumar, G. O. Hollist, B. Borhan, Org. Lett.,
2003, 5, 1031-1034.
A novel, metal-free oxidation system for the catalytic synthesis of aldehydes
and ketones using TEMPO and a quarternary ammonium salt as catalysts and Oxone
as oxidant proved especially successful for the synthesis of ketones. The mild
conditions tolerate even sensitive silyl protective groups which can otherwise
be cleaved in the presence of Oxone.
C. Bolm, A. S. Magnus, J. P. Hildebrand, Org. Lett., 2000,
2, 1173-1175.
C. Bolm, A. S. Magnus, J. P. Hildebrand, Org. Lett., 2000,
2, 1173-1175.
Catalytic use of o-iodoxybenzoic acid (IBX) in the presence of Oxone
as a co-oxidant is demonstrated for the oxidation of primary and secondary
alcohols. In addition, the in situ oxidation of 2-iodosobenzoic acid (IBA)
and even commercially available 2-iodobenzoic acid (2IBAcid) by Oxone to IBX
allows the use of these less hazardous reagents, in place of potentially
explosive IBX, as catalytic oxidants.
A. P. Thottumkara, M. S. Bowsher, T. K. Vinod, Org. Lett., 2005,
7, 2933-2936.
A. P. Thottumkara, M. S. Bowsher, T. K. Vinod, Org. Lett., 2005,
7, 2933-2936.
A highly chemo- and enantioselective epoxidation of conjugated cis-enynes
using readily available glucose-derived ketones as catalysts and Oxone as
oxidant forms cis-propargyl epoxides in high ee's. The interaction
between the alkyne substrate and the oxazolidinone moiety of the ketone catalyst
are important for the stereodifferentiation.
C. P. Burke, Y. Shi, J. Org. Chem., 2007,
72, 4093-4097.
Specific oxidation protocols have been developed for the cleavage of styrenes,
aliphatic olefins, and terminal aliphatic olefins to carbonyl compounds with
ruthenium trichloride as catalyst. Olefins that are not fully substituted are
converted to aldehydes rather than carboxylic acids.
D. Yang, C. Zhang, J. Org. Chem., 2001, 66,
4814-4818.
D. Yang, C. Zhang, J. Org. Chem., 2001, 66,
4814-4818.
The OsO4-catalyzed direct oxidation of olefins via the
carbon-carbon cleavage of an osmate ester by the action of oxone allows the
preparation of ketones or carboxylic acids in high yields. This method
should be applicable as an alternative to ozonolysis.
B. R. Travis, R. S. Narayan, B. Borhan, J. Am. Chem. Soc., 2002,
124, 3824-3825.
B. R. Travis, R. S. Narayan, B. Borhan, J. Am. Chem. Soc., 2002,
124, 3824-3825.
A new mild RuO4-catalyzed ketohydroxylation of olefins is
reported. α-Hydroxy ketones were obtained with high regioselectivity and
in good to excellent yields.
B. Plietker, J. Org. Chem., 2003,
68, 7123-7125.
Transformation of epoxides to β-alkoxy alcohols, acetonides, and α-alkoxy
ketones is achieved by using molybdenum(VI) dichloride dioxide (MoO2Cl2)
as a catalyst. Alcohol, aldehyde, oxime, tosyl, and tert-butyldimethylsilyl
functional groups are tolerated during the methanolysis and acetonidation of the
functionalized epoxides.
K. Jeyakumar, D. K. Chand, Synthesis, 2008,
807-819.
Grubbs' 2nd generation metathesis catalyst can be used in tandem olefin
metathesis/oxidation protocols. These ruthenium-catalyzed processes provide
access to cis-diols or α-hydroxy ketones from simple olefinic starting
materials.
A. A. Scholte, M. H. An, M. L. Snapper, Org. Lett., 2006, 8, 4759-4762.
A mild and convenient oxidative Nef reaction using Oxone is described.
Following this procedure primary and secondary nitroalkanes generates
carboxylic acids and ketones, respectively, both in good yields.
P. Ceccherelli, M. Curini, M. C. Marcotullino, F. Epifano, O. Rosati, Synth. Commun., 1998, 28, 3057-3064.
A two-step sequence of asymmetric dihydroxylation and regioselective
monooxidation gave enantiopure α-hydroxy ketones (acyloins). The
combination of RuCl3/Oxone/NaHCO3 was used in the
first catalytic regioselective oxidation of vic-diols to
α-ketols.
B. Plietker, Org. Lett., 2004, 6, 289-291.
An efficient method for the oxidative cleavage of internal and terminal
alkynes to carboxylic acids using a combination of RuO2/Oxone/NaHCO3
in a CH3CN/H2O/EtOAc solvent system is described.
Various alkynes, regardless of their electron density, were oxidized to
carboxylic acids in excellent yield.
D. Yang, F. Chen, Z.-M. Dong, D.-W. Zhang, J. Org. Chem., 2004, 69, 209-212.
Iodocyclization of unsaturated tosylamides promoted by Oxone oxidation of KI
afforded, in good yields, N-tosyl iodopyrrolidines and piperidines.
M. C. Marcotullio, V. Campagna, S. Sternativo, F. Costantino, M. Curini,
Synthesis, 2006, 2760-2766.
Addition of oxone to a mixture of a 1,2-phenylenediamine and an
aldehyde in wet DMF results in rapid formation of benzimidazoles under very mild
conditions. Products are isolated in high purity in most cases by simple aqueous
precipitation. The reaction is applicable to a wide range of substrates but does
not allow the conversion of aldehydes that are sensitive to oxone under acidic
reaction conditions.
P. L. Beaulieu, B. Haché, E. von Moos, Synthesis, 2003, 1683-1692.
α-Bromo- or α-chloro-α,β-unsaturated carbonyl compounds were prepared in good
yields by addition of hydrobromic acid or hydrochloric acid to α,β-unsaturated
carbonyl compounds in the presence of Oxone in CH2Cl2
followed by treatment of the resulting dihalides with Et3N.
K.-M. Kim, I.-H. Park, Synthesis,
2004, 2641-2644.
