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Further Information

Related Reactions
Curtius Rearrangement
Schmidt Reaction

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.

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

An efficient Beckmann rearrangement at room temperature involves an eosin Y catalyzed, visible-light-mediated in situ formation of the Vilsmeier-Haack reagent from CBr4 and a catalytic amount of DMF. This operationally simple method for the activation of ketoximes avoids the need for any corrosive, water-sensitive reagents and elevated temperatures.
V. P. Srivastava, A. K. Yadav, L. D. S. Yadav, Synlett, 2014, 25, 665-670.

Dichloroimidazolidinedione-Activated Beckmann Rearrangement of Ketoximes for Accessing Amides and Lactams
Y. Gao, J. Liu, Z. Li, T. Guo, S. Xu, H. Zhu, F. Wei, S. Chen, H. Gebru, K. Guo, J. Org. Chem., 2018, 83, 2040-2049.

Beckmann Rearrangement of Ketoximes to Lactams by Triphosphazene Catalyst
M. Hashimoto, Y. Obora, S. Sakaguchi, Y. Ishii, J. Org. Chem., 2008, 73, 2894-2897.

Efficient Iodine-Mediated Beckmann Rearrangement of Ketoximes to Amides under Mild Neutral Conditions
N. C. Ganguly, P. Mondal, Synthesis, 2010, 3705-3709.

Beckmann Rearrangement of Oximes under Very Mild Conditions
L. De Luca, G. Giacomelli, A. Porcheddu, J. Org. Chem., 2002, 67, 6272-6274.

Bromodimethylsulfonium Bromide-ZnCl2: A Mild and Efficient Catalytic System for Beckmann Rearrangement
L. D. S. Yadav, R. Patel, V. P. Srivastava, Synthesis, 2010, 1771-1776.

Au/Ag-Cocatalyzed Aldoximes to Amides Rearrangement under Solvent- and Acid-Free Conditions
R. S. Ramón, J. Bosson, S. Díez-González, N. Marion, S. P. Nolan, J. Org. Chem., 2010, 75, 1197-1202.

Beckmann reaction of oximes catalysed by chloral: mild and neutral procedures
S. Chandrasekhar, K. Gopalaiah, Tetrahedron Lett., 2003, 44, 755-756.

Mercury-Catalyzed Rearrangement of Ketoximes into Amides and Lactams in Acetonitrile
C. Ramalingan, Y.-T. Park, J. Org. Chem., 2007, 72, 4536-4538.

Solvent-Free and One-Step Beckmann Rearrangement of Ketones and Aldehydes by Zinc Oxide
H. Sharghi, M. Hosseini, Synthesis, 2002, 1057-1059.