The White–Chen catalyst is an Iron-based coordination complex named after Professor M. Christina White and her graduate student Mark S. Chen.

The catalyst is used along with hydrogen peroxide and acetic acid additive to oxidize aliphatic sp3 C-H bonds in organic synthesis.

[1][2][3][4] Oxidations with the catalyst have proven to be remarkably predictable based on sterics, electronics, and stereoelectronics allowing for aliphatic C–H bonds to be thought of as a functional group in the streamlining of organic synthesis.

The C-H bond shaded in yellow is further from the bulky group, is less sterically hindered, and will therefore be the site of oxidation by the catalyst in this case.

In the case at the right the C–H bond highlighted in yellow is in close proximity to the directing group and would be the expected site for oxidation in this substrate.

[11] The substrate on the left is the starting material and when the R group is an ester the oxidation takes place with low yields of about 26% due to electronic deactivation of the proximal C—H bond.

In general the White Chen catalyst will bind to a carboxylic acid groups and this can be used to override negative electronic, steric, and stereoelectronic effects within a molecule.

The White–Chen catalyst relies on the constructive combination of inherent electronic, steric, and stereoelectronic factors within a substrate to favor one site of oxidation.

The catalyst quickly reacts with hydrogen peroxide, believed to be catalyzed by the acetic acid, and forms and iron-oxo intermediate.