Decarboxylative Halogenation of Indolecarboxylic Acids Using Hypervalent Iodine(III) Reagent and Its Application to the Synthesis of Polybromoindoles
作者:Hiromi Hamamoto、Yasuyoshi Miki、Hideaki Umemoto、Misako Umemoto、Chiaki Ohta、Emi Fujita、Akira Nakamura、Tomohiro Maegawa
DOI:10.3987/com-14-13162
日期:——
Hypervalent iodine mediated decarboxylative halogenation of indoledicarboxylic acid derivatives was studied. The treatment of 1-methylindole-2,3-dicarboxylic acid with phenyliodine diacetate (PIDA) in the presence of lithium bromide gave 1-methyl-3,3-bromooxindole. However, the reaction of 1-(phenylsulfonyl)indole-2,3-dicarboxylic acid with PIDA in the presence of lithium bromide afforded 2,3-dibromo-1-(phenylsulfonyl)indole. In a similar manner, the 2,3-dichloro- and 2,3-diiodoindole derivatives could be obtained by the reaction of the indole-2,3-dicarboxylic acids with PIDA in the presence of lithium chloride and iodide. This method was optimized to the synthesis of polybromoindole alkaloids.