Indium in Organic Synthesis

Abstract The various applications of indium in organic synthesis are highlighted in this review. Major fields are Barbier-type reactions, especially allyl additions to carbonyl compounds, and Reformatsky reactions. Special emphasis is placed on reactions, which have been examined only recently, i.e. reductions of various functionalities, indium-catalyzed reactions and palladium/indium-mediated reactions. 1 Introduction 2 Barbier-Type Reactions 2.1 Indium-Mediated Additions to Aldehydes and Ketones 2.2 The Role of the Allyl Halide 2.3 Diastereoselectivity 2.4 Regioselectivity 2.5 Enantioselectivity 2.6 Indium-Mediated Additions to Further Carbonyl Derivatives 2.7 Indium-Mediated Additions to C-C Multiple Bonds 2.8 Reaction of Non-Allylic Substrates in Barbier-Type Reactions 3 Palladium-Catalyzed Allylic Substitutions and Cross-Couplings of Indium Intermediates 4 Reformatsky-Type Reactions 5 Indium-Catalyzed Reactions 6 Nucleophilic Substitutions Using Intermediate Allylindium Compounds 7 Allylindium Reagents 8 Indium-Mediated Reductions 8.1 Reduction and Deoxygenation of N-Containing Functionalities 8.2 Reductive Dehalogenations 8.3 Reduction of Carbonyl Groups 8.4 Miscellaneous Reductions 9 Conclusion