3-Chloroperoxybenzoic acid, MCPBA, meta-Chloroperbenzoic acid
MCPBA is a strong oxidizing agent, which is comparable with other peracids. Advantages of 3-chloroperbenzoic acid is its handling, because it is present as powder, which can be kept in the refrigerator. Nevertheless, material of purity >75% is rarely available commercially, since the pure compound is not particularly stable. Therefore the transport in airplanes with a content of > 72% is forbidden. Main pollution is 3-chlorobenzoic acid (10%) as well as for safety reasons water.

MCPBA is versatile applicable as peracid for use in laboratories.
Main areas are the oxidation of
- aldehydes and ketones to esters (Bayer-Villiger-Oxidation)
- olefines to epoxides
- sulfides to sulfoxides and sulfones
- amines to nitroalkanes, nitroxides or N-oxides
However, for reasons of the atomic economy, the use of MCPBA in production should be avoided. The research concentrates within this area rather on the use of hydrogen peroxide in connection with suitable catalysts or in situ generated, simpler peracids, such as peracetic acid or on potassium peroxymonosulfate (Oxone). In many reactions MCPBA with an outstanding reactivity is however more selective than hydrogen peroxide and other peracids.
Name Reactions
Recent Literature

Use of a solvent with greater
density than the fluorous phase is an alternative to the U-tube method
in phase-vanishing reactions in cases where both reactants are less
dense than the fluorous phase.
N. K. Jana, J. G. Verkade, Org. Lett.,
2003,
5, 3787-3790.

N. K. Jana, J. G. Verkade, Org. Lett.,
2003,
5, 3787-3790.

N. K. Jana, J. G. Verkade, Org. Lett.,
2003,
5, 3787-3790.

The results of a highly diastereoselective epoxidation of allylic diols
derived from Baylis-Hillman adducts are reported.
R. S. Porto, M. L. A. A. Vasconcellos, E. Ventura, F. Coelho,
Synthesis, 2005, 2297-2306.

Sequential treatment of a 1,2-disubstituted olefin with m-CPBA, Br3CCO2H,
and DBU results in the one-pot, stereospecific conversion of the olefin to the
corresponding disubstituted cyclic carbonate. When a solution of a secondary
allylic or homoallylic amine and Br3CCO2H is sequentially
treated with m-CPBA then DBU, the product of the reaction is a cyclic
carbamate.
S. G. Davies, A. M. Fletcher, W. Kurosawa, J. A. Lee, G. Poce, P. M. Roberts,
J. E. Thomson, D. M. Williamson, J. Org. Chem., 2010,
75, 7745-7756.

Several amides were obtained in
high yields by an efficient method from the corresponding imines which
are readily prepared from aldehydes. This procedure involves the
oxidation of aldimines with m-CPBA and BF3·OEt2.
In this reaction, the product is strongly influenced by the electron
releasing capacity of the aromatic substituent (Ar).
G. An, M. Kim, J. Y. Kim, H. Rhee,
Tetrahedron Lett., 2003, 44, 2183-2186.

An efficient oxidation of cyclic acetals provided hydroxy alkyl esters in good
yields in the presence of MCPBA.
J. Y. Kim, H. Rhee, M. Kim, J. Korean Chem.
Soc., 2002, 46, 479-483.

Various α-tosyloxyketones were efficiently prepared in high yields from the
reaction of ketones with m-chloroperbenzoic acid and p-toluenesulfonic acid in
the presence of a catalytic amount of iodobenzene.
Y. Yamamoto, H. Togo, Synlett,
2006, 798-800.

Reaction of methyl sulfinates with lithium amides followed oxidation of the
resulting sulfinamides provides primary, secondary, and tertiary alkane-, arene-
and heteroarenesulfonamides in high yields. This protocol avoids the use of
hazardous, unstable, or volatile reagents and does not affect the
configurational stability of the amines.
J. L. C. Ruano, A. Parra, F. Yuste, V. M. Mastranzo, Synthesis, 2008,
311-312.

β-Piperidinoethylsulfides can be oxidized by m-chloroperbenzoic acid to
intermediates containing both N-oxide and sulfone functions. These
undergo a Cope-type elimination to a vinylsulfone that can be captured by amines
to afford β-aminoethylsulfones. The synthetic methodology developed can be
utilized in multiple-parallel format and has numerous potential applications in
medicinal chemistry.
R. J. Gruffin, A. Henderson, N. J. Curtin, A. Echalier, J. A. Endicott, I. R.
Hardcastle, D. R. Newell, M. E. M. Noble, L.-Z. Wang, B. T. Golding, J. Am. Chem. Soc., 2006,
128, 6012-6013.

The synthesis of N-cyanosulfilimines can readily be achieved by reaction
of the corresponding sulfides with cyanogen amine in the presence of a base and
NBS or I2 as halogenating agents. Oxidation followed by decyanation
affords synthetically useful sulfoximines.
O. García Mancheño, O. Bistri, C. Bolm, Org. Lett., 2007,
9, 3809-3811.

Iodobenzene can be used as a recyclable catalyst in combination with m-chloroperbenzoic
acid as the terminal oxidant for an efficient and regioselective monobromination
of electron-rich aromatic compounds. The bromination of electron-rich aromatic
compounds with lithium bromide was fast in tetrahydrofuran at room temperature,
providing regioselective monobrominated products in good yields.
Z. Zhou, X. He, Synthesis, 2011,
207-209.

A new, regiospecific, sequential one-pot synthesis of symmetrical and
unsymmetrical diaryliodonium tetrafluoroborates, which are the most popular
salts in metal-catalyzed arylations, is fast and high-yielding and has a large
substrate scope. Furthermore, the corresponding diaryliodonium triflates can
conveniently be obtained via an in situ anion exchange.
M. Bielawski, D. Aili, B. Olofsson, J. Org. Chem., 2008,
73, 4602-4607.

One-pot syntheses of neutral and electron-rich [hydroxy(tosyloxy)iodo]arenes (HTIBs)
from iodine and arenes avoid the need for expensive iodine(III) precursors. A
large set of HTIBs, including a polyfluorinated analogue, can be obtained from
the corresponding aryl iodides under mild conditions, without excess reagents,
in high yields.
E. A. Merritt, V. M. T. Carneiro, L. F. Silva Jr., B. Olofsson, J. Org. Chem., 2010,
75, 7416-7419.

A direct synthesis of symmetric and unsymmetric electron-rich diaryliodonium
salts delivers diaryliodonium tosylates in high yields using MCPBA and
toluenesulfonic acid. An in situ anion exchange has also been developed, giving
access to the corresponding triflate salts.
M. Zhu, N. Jalalian, B. Olofsson, Synlett, 2008,
592-596.



