Beckmann Rearrangement

An acid-induced rearrangement of oximes to give amides.

This reaction is related to the Hofmann and Schmidt Reactions and the Curtius Rearrangement, in that an electropositive nitrogen is formed that initiates an alkyl migration.

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Mechanism of the Beckmann Rearrangement

Oximes generally have a high barrier to inversion, and accordingly this reaction is envisioned to proceed by protonation of the oxime hydroxyl, followed by migration of the alkyl substituent "trans" to nitrogen. The N-O bond is simultaneously cleaved with the expulsion of water, so that formation of a free nitrene is avoided.

Recent Literature

he Beckmann Rearrangement Executed by Visible-Light-Driven Generation of Vilsmeier-Haack Reagent

Dichloroimidazolidinedione-Activated Beckmann Rearrangement of Ketoximes for Accessing Amides and Lactams

Scope and Mechanism of a True Organocatalytic Beckmann Rearrangement with a Boronic Acid/Perfluoropinacol System under Ambient Conditions

Beckmann Rearrangement of Ketoximes to Lactams by Triphosphazene Catalyst

Efficient Iodine-Mediated Beckmann Rearrangement of Ketoximes to Amides under Mild Neutral Conditions

Beckmann Rearrangement of Oximes under Very Mild Conditions

Bromodimethylsulfonium Bromide-ZnCl₂: A Mild and Efficient Catalytic System for Beckmann Rearrangement

Hypervalent Iodine-Mediated Beckmann Rearrangement of Ketoximes

Au/Ag-Cocatalyzed Aldoximes to Amides Rearrangement under Solvent- and Acid-Free Conditions

Beckmann reaction of oximes catalysed by chloral: mild and neutral procedures

Mercury-Catalyzed Rearrangement of Ketoximes into Amides and Lactams in Acetonitrile

Direct and Catalytic Amide Synthesis from Ketones via Transoximation and Beckmann Rearrangement under Mild Conditions

Deacetylative Amination of Acetyl Arenes and Alkanes with C-C Bond Cleavage

Solvent-Free and One-Step Beckmann Rearrangement of Ketones and Aldehydes by Zinc Oxide