Introduction to Oxidation and Reduction
Oxidation
Most of the common oxidizing agents used in organic chemistry are inorganic compounds, such as:
- Tab.1
- Frequently used oxidizing agents in organic chemistry
| permanganate | |
| manganese dioxide | |
| dichromate | |
| chromium oxide | |
| osmium tetroxide | |
| hydrogen peroxide | |
| peroxide | |
| chlorine | |
| hypochlorite | |
| / cat. | air + transition metal oxides as catalysts |
| / hν | irradiation with photosensitizers in air (photooxidation) |
| electrochemical processes (anionic oxidation) |
The oxidation of functional groups, such as C=C double bonds, alcohols, aldehydes, ketones, benzylic and allylic H atoms or functional groups containing N, S or P, is carried out in most cases with specifically tailored reagents that meet certain conditions. On the other hand, the selective oxidation of C-H bonds in alkanes and aromatic compounds has not been solved satisfactorily. Though tertiary H atoms are more reactive than secondary and primary ones, the oxidation of hydrocarbons usually leads to a mixture of products and structural fragmentation (in extreme cases combustion can lead to CO2 and water).
Organic oxidation reactions are normally divided into three categories:
- Dehydrogenation (removal of H2 )
- Oxidation by replacement of hydrogen with oxygen
- Oxidation by addition of oxygen
