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.
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.
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.
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.
