2008

HalogenationO 0235 Bromination of Ketones with H2O2—HBr "On Water". — α-Bromination of dial-

kyl, aryl alkyl ketones, 1,3-diketones, β-ketoesters, and cyclic ketones proceeds in an aqueous H2O2-HBr system with high selectivity for monobromination vs. dibromina-tion and without the need for a catalyst or organic solvent. The reactivity of the system can be manipulated by an additional amount of water. The title system can also be used for tandem oxidation-bromination reactions to synthesize α-bromoketones directly from alcohols [cf. (X)->(XI)]. The "green" features of this protocol include the use of inexpensive reagents and a lower impact on the environment making this process a good alternative to existing bromination methods. — (PODGORSEK, A.; STAVBER, S.; ZUPAN, M.; ISKRA*, J.; Green Chem. 9 (2007) 11, 1212-1218; Jozef Stefan Inst., Univ. Ljubljana, 1000 Ljubljana, Slovenia; Eng.) — H. Hoennerscheid

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