| Kornblum oxidation | |
|---|---|
| Named after | Nathan Kornblum |
| Reaction type | Organic redox reaction |
TheKornblum oxidation, named afterNathan Kornblum, is anorganic oxidation reaction that convertsalkyl halides andtosylates intocarbonyl compounds.[1][2][3]
Similar tosulfonium-based oxidation of alcohols to aldehydes reactions, the Kornblum oxidation creates an alkoxysulphonium ion, which, in the presence of a base, such astriethylamine (Et3N), undergoes anelimination reaction to form thealdehyde orketone.
The first step is anSN2 reaction, so it is subject to the usualleaving group limitations of that reaction. Whileiodides work well, evenbromides are often not reactive enough to be displaced by the DMSO. However, using an additive such assilver tetrafluoroborate allows the reaction to work on a wider range of substrates, as often seen for alkyl-halide substitutions, or they can be converted first to the corresponding alkyl tosylate.[4][5] The reaction was initially limited to activated substrates, such asbenzylic and α-halo ketones. To increase the range of viable substrates, Kornblum later added a preliminary conversion of the halide to a tosylate, which is a better leaving group, to the protocol, and usingpyridine-N-oxide or similar reagents rather than DMSO.[5] TheGanem oxidation built on this latter modification, expanding on the use of variousN-oxide reagents.