Synthesis of α-Bromoketones

Recent Literature

1-Arylethanones and related compounds are rapidly brominated in dioxane with the H₂O₂-HBr aq system, resulting in the replacement of two hydrogen atoms in the methyl group with bromine. The reaction is also accompanied by bromination of the aromatic ring provided that the latter contains electron-donating substituents.
A. O. Terent'ev, S. V. Khodykin, I. B. Krylov, Y. N. Ogibin, G. I. Nikishin, Synthesis, 2006, 1087-1092.

Utilizing the full potential of IBX, a mild, selective, and facile method enables a direct conversion of olefins into the corresponding α-bromo ketones in the presence of 1.1 equivalents each of o-iodoxybenzoic acid and tetraethylammonium bromide.
S. S. Deshmukh, K. H. Chaudhari, K. G. Akamanchi, Synlett, 2011, 81-83.

Efficient oxidative α-halogenation of 1,3-dicarbonyl compounds has been achieved by employing a system comprising of sub-stoichiometric amounts of TiX₄ (X = Cl, Br) in the presence of environmentally benign hydrogen peroxide (H₂O₂) or peracetic acid (MeCO₃H) as the oxidants. The end point of the reaction is accompanied by a sharp colour change.
R. Akula, M. J. Galligan, H. Ibrahim, Synthesis, 2011, 347-351.

Active methylene compounds can be chemoselectively brominated in high yields using potassium bromide, hydrochloric acid, and hydrogen peroxide at room temperature.
M. Kirihara, S. Ogawa, T. Noguchi, K. Okubo, Y. Monma, I. Shimizu, R. Shimosaki, A. Hatano, Y. Hirai, Synlett, 2006, 2287-2289.

1,3-keto esters and 1,3-diketones have been effectively and regioselectively α-monobrominated using bromodimethylsulfonium bromide as reagent.
A. T. Khan, M. A. Ali, P. Goswami, L. H. Choudhury, J. Org. Chem., 2006, 71, 8961-8963.

An efficient one-pot transformation of β-hydroxycarbonyl compounds to α-brominated 1,3-dicarbonyl compounds is achieved with MoO₂Cl₂ in the presence of N-bromosuccinimide. All the reactions were carried out under mild conditions and provide good yields. No bromination occurs at benzylic and allylic positions.
K. Jeyakumar, D. K. Chand, Synthesis, 2009, 306-310.

K. Jeyakumar, D. K. Chand, Synthesis, 2009, 306-310.

Poly{[4-(hydroxy)(tosyloxy)iodo]styrene} was efficient in the halotosyloxylation reaction of alkynes with iodine or NBS or NCS. The polymer reagent could be regenerated and reused.
J.-M. Chen, X. Huang, Synthesis, 2004, 1557-1558.