Sulfoxidation

in chemistry, sulfoxidation refers to two distinct reactions.

Reactions of alkenes with sulfur dioxide

In one meaning, sulfoxidation refers to the reaction of alkanes with a mixture of sulfur dioxide and oxygen. This reaction is employed industrially to produce alkyl sulfonic acids, which are used as surfactants. The reaction requires UV-radiation.
The reaction favors secondary positions in accord with its free-radical mechanism. Mixtures are produced. Semiconductor-sensitized variants have been reported.

Sulfoxidation can also refer to the oxidation of a thioether to a sulfoxide.
For unsymmetrical sulfides, the sulfoxide will be chiral. Significant effort have led to asymmetric versions of the sulfide to sulfoxide reaction..
Sulfoxides can be further oxidized to sulfones, as illustrated with diphenylsulfone:
Many oxidants have been demonstrated, but from the perspective of green chemistry, hydrogen peroxide is favored.