Indium Metal and Its Halides in Organic Synthesis

This review highlights the applications of indium metal and indium(III) halides in organic synthesis with particular reference to regio-, stereo-, and chemoselectivity. Indium-mediated reactions include the regioselective allylation of alkynes, the stereoselective debromination of vic-aryl-substituted dibromides, the homocoupling of alkyl/aryl halides, and the reduction of α-halocarbonyl compounds. Indium trichloride has been used as a Lewis acid catalyst in epoxide rearrangements, in the synthesis of α-amino phosphonates, and in the construction of the quinoline system. Indium triiodide has proven to be a very efficient catalyst for transesterification processes.