Sandmeyer Reaction

The substitution of an aromatic amino group is possible via preparation of its diazonium salt and subsequent displacement with a nucleophile (Cl-, I-, CN-, RS-, HO-). Many Sandmeyer Reactions proceed under copper(I) catalysis, while the Sandmeyer-type reactions with thiols, water and potassium iodide don't require catalysis.

The Sandmeyer Reaction is a very important transformation in aromatic chemistry, because it can result in some substitution patterns that are not achievable by direct substitution.

Fluorination is possible by using the related  Schiemann Reaction.

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Mechanism of the Sandmeyer Reaction

Recent Literature

Catalytic Sandmeyer Bromination
I. P. Beletskaya, A. S. Sigeev, A. S. Peregudov, P. V. Petrovskii, Synthesis, 2007, 2534-2538.

Halo- and Azidodediazoniation of Arenediazonium Tetrafluoroborates with Trimethylsilyl Halides and Trimethylsilyl Azide and Sandmeyer-Type Bromodediazoniation with Cu(I)Br in [BMIM][PF₆] Ionic Liquid
A. Hubbard, T. Okazaki, K. K. Laali, J. Org. Chem., 2008, 73, 316-319.

Unusually Stable, Versatile, and Pure Arenediazonium Tosylates: Their Preparation, Structures, and Synthetic Applicability
V. D. Filimonov, M. Trusova, P. Postnikov, E. A. Krasnokutskaya, Y. M. Lee, H. Y. Hwang, H. Kim, K.-W. Chi, Org. Lett., 2008, 10, 3961-3964.

Sulfonic Acid Based Cation-Exchange Resin: A Novel Proton Source for One-Pot Diazotization-Iodination of Aromatic Amines in Water
V. D. Filimonov, N. I. Semenischeva, E. A. Krasnokutskaya, A. N. Tretyakov, H. Y. Hwang, K.-W. Chi, Synthesis, 2008, 185-187.

A New, One-Step, Effective Protocol for the Iodination of Aromatic and Heterocyclic Compounds via Aprotic Diazotization of Amines
E. A. Krasnokutskaya, N. I. Semenischeva, V. D. Filimonov, P. Knochel, Synthesis, 2007, 81-84.