Iodoarene-Mediated α-Tosyloxylation of Ketones with MCPBA and p-Toluenesulfonic Acid
作者:Hideo Togo、Ayumi Tanaka、Katsuhiko Moriyama
DOI:10.1055/s-0030-1260948
日期:2011.8
Alkyl aryl ketones and dialkyl ketones could be converted into the corresponding α-tosyloxy ketones by the reaction with MCPBA and p-toluenesulfonic acid monohydrate (PTSAËH2O) in the presence of a catalytic amount of molecular iodine (I2) in a mixture of acetonitrile and 2,2,2-trifluoroethanol, although the yields were dependent on the ketones (method A). The same conversion of alkyl aryl ketones and dialkyl ketones into the corresponding α-tosyloxy ketones could be smoothly carried out by the reaction with MCPBA and PTSAËH2O in the presence of catalytic amounts of iodine and tert-butylbenzene in a mixture of acetonitrile and 2,2,2-trifluoroethanol (method B). In those reactions, p-iodotoluene and 4-tert-butyl-1-iodobenzene were formed at first in method A and method B, respectively, and then they were converted into p-[(hydroxy)(tosyloxy)]iodotoluene and 4-tert-butyl-1-[(hydroxy)(tosyloxy)iodo]benzene by the reaction with MCPBA and PTSAËH2O. p-[(Hydroxy)(tosyloxy)]iodotoluene and 4-tert-butyl-1-[(hydroxy)-(tosyloxy)iodo]benzene worked as an α-tosyloxylation reagent of ketones.