Mild α-Halogenation Reactions of 1,3-Dicarbonyl Compounds Catalyzed by Lewis Acids

2002-09-26T00:00:00Z (GMT) by Dan Yang Yi-Long Yan Bob Lui
Lewis acid Mg(ClO<sub>4</sub>)<sub>2</sub>, combined with NBS, in CH<sub>3</sub>CN or EtOAc provided mild and fast bromination of 1,3-dicarbonyl compounds. In particular, this protocol could be applied to the α-monobromination of α-unsubstituted β-keto esters. Similar Lewis acid catalysis was also extended to the α-chlorination and iodination of 1,3-dicarbonyl compounds with NCS and NIS, respectively.