Sodium percarbonate
The name "sodium percarbonate" (SPC) does not reflect the structure of this oxidizing agent, which is in fact a carbonate perhydrate: 2 Na2CO3 • 3 H2O2. Although SPC is very storage-stable if dry, the solid material has a slight vapour pressure of hydrogen peroxide leading to exchange with water or to violent reactions with oxidizable substrates, even in the solid state.
Sodium percarbonate is a source of highly concentrated hydrogen peroxide in non-aqueous systems, even if the material is not fully soluble. The addition of small amounts of water or sonication can increase the rate of oxidation. For example, sodium percarbonate allows the convenient preparation of peroxyacids from acid chlorides, and even from the acids themselves. Thus, SPC can be used in epoxidations and Baeyer-Villiger oxidations in the presence of an acylating agent:
G. A. Olah, Q. Wang, N. J. Trivedi, G. K. S. Prakash, Synthesis,
1991, 739-740.
The slight change in reactivity in aqueous solution might be attributed to the formation of true percarbonates, but the dominant chemistry is that of hydrogen peroxide:
Percarbonate behaves as an electrophile, because the driving force is the formation of carbonate:
For a more detailed explanation, please refer to A. McKillop, W. R. Sanderson, Tetrahedron, 1995, 51, 6145-6166. DOI
For applications in organic synthesis see the following reviews:
J. Muzart, Synthesis, 1995, 1325-1347.
DOI
A. McKillop, W. R. Sanderson, J. Chem. Soc., Perkin Transactions 1,
2000, 471-476.
DOI
Recent Literature
Sodium percarbonate in trifluoroacetic acid is an effective
reagent for the Baeyer-Villiger oxidation of ketones to esters. The scope and
limitations of the reaction were explored.
G. A. Olah, Q. Wang, N. J. Trivedi, G. K. S. Prakash, Synthesis,
1991, 739-740.
The oxidation of primary and secondary alcohols by sodium percarbonate in the presence of catalytic
amounts of both molybdenyl acetylacetonate and Adogen 464 gave fair to high yields
of the corresponding carbonyl compounds.
S. Maignien, S. Aït-Mohand, J. Muzart, Synlett,
1996, 439-440.
In MTO-catalyzed epoxidation, aqueous hydrogen peroxide is typically added
dropwise to a dichloromethane solution of the olefin, pyrazole as accelerant,
and MTO. The use of sodium percarbonate (SPC) offers a slow
release of hydrogen peroxide, that can be accelerated using trifluoroacetic acid.
A. R. Vaino, J. Org. Chem., 2000,
65, 4210-4212.
The use of ammonium iodide as the catalyst and sodium percarbonate as the
co-oxidant enables a transition-metal-free direct α-C-H amination of ketones. A
wide range of ketone ((hetero)aromatic or nonaromatic ketones) and amine (primary/secondary
amines, anilines, or amides) substrates undergo cross-coupling to generate
synthetically useful α-amino ketones.
Q. Jiang, B. Xu, A. Zhao, J. Jia, T. Liu, C. Guo, J. Org. Chem., 2014,
79, 8750-8756.
Sodium percarbonate is an ideal and efficient oxygen source for the oxidation of
tertiary nitrogen compounds to N-oxides in excellent yields in the
presence of various rhenium-based catalysts under mild reaction conditions.
S. L. Jain, J. K. Joseph, B. Sain, Synlett, 2006,
2661-2663.
S. L. Jain, J. K. Joseph, B. Sain, Synlett, 2006,
2661-2663.