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.
The Beckmann Rearrangement Executed by Visible-Light-Driven Generation of Vilsmeier-Haack Reagent
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.
Scope and Mechanism of a True Organocatalytic Beckmann Rearrangement with a Boronic Acid/Perfluoropinacol System under Ambient Conditions
X. Mo, T. D. R. Morgan, H. T. Ang, D. G. Hall, J. Am. Chem. Soc., 2018, 140, 5264-5271.
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.
Hypervalent Iodine-Mediated Beckmann Rearrangement of Ketoximes
R. Oishi, K. Segi, H. Hamamoto, A. Nakamura, T. Maegawa, Y. Miki, Synlett, 2018, 29, 1465-1468.
Photocatalyzed Triplet Sensitization of Oximes Using Visible Light Provides a Route to Nonclassical Beckmann Rearrangement Products
X. Zhang, T. Rovis, J. Am. Chem. Soc., 2021, 143, 21211-21217.
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.
Zinc(II) catalyzes a single-step protocol for the Beckmann rearrangement using hydroxylamine-O-sulfonic acid (HOSA) as the nitrogen source in water. This environmentally benign and operationally simple method efficiently produces secondary amides under open atmosphere in a pure form after basic aqueous workup.
S. Verma, P. Kumar, A. K. Khatana, D. Chandra, A. K. Yadav, B. Tiwari, J. L. Jat, Synthesis, 2020, 52, 1841-1846.
Cu(OTf)2-Catalyzed Beckmann Rearrangement of Ketones Using Hydroxylamine-O-sulfonic Acid (HOSA)
S. Munnuri, S. Verma, D. Chandra, R. R. Anugu, J. R. Falck, J. L. Jat, Synthesis, 2019, 51, 3709-3714.
Direct and Catalytic Amide Synthesis from Ketones via Transoximation and Beckmann Rearrangement under Mild Conditions
K. Hyodo, G. Hasegawa, N. Oishi, K. Kuroda, K. Uchida, J. Org. Chem., 2018, 83, 13080-13087.
Deacetylative Amination of Acetyl Arenes and Alkanes with C-C Bond Cleavage
K. Hyodo, G. Hasegawa, H. Maki, K. Uchida, Org. Lett., 2019, 21, 2818-2822.
Solvent-Free and One-Step Beckmann Rearrangement of Ketones and Aldehydes by Zinc Oxide
H. Sharghi, M. Hosseini, Synthesis, 2002, 1057-1059.