Sulfonic acid functionalized silica has been found to be a highly efficient and versatile catalyst for alpha-monobromination of carbonyl compounds (cyclic and acyclic ketones, 1,3-diketones, beta-ketoesters, lactones, coumaranones and lactams) using N-bromosuccinimide under mild reaction conditions. The alpha-monobrominated products were obtained in very high yields and in short reaction times. The catalyst works under heterogeneous conditions and can be recyclable. (c) 2006 Elsevier B.V. All rights reserved.