Tri-n-butyltin Hydride as Reagent in Organic Synthesis

The considerable growth of the application of tri-n-butyltin hydride (TBTH) in organic synthesis since 1975 is reviewed. Four main aspects are included: a) selective transformation of C-X (X=halide, OH, S, Se, NH₂, NO₂, COOH) to C-H bonds, b) addition to C=C, C≡C, C=Y ( Y = O, S, N) groups, c) use of intermediate carbon centered radicals from a) or b) for intra- or intermolecular C-C coupling, which occurs mostly regio- and stereoselectively, and d) use in palladium-catalyzed syntheses, e.g. of aldehydes. 1. Introduction 2. Dehalogenation 2.1. Replacement of Halogen by Hydrogen or Deuterium at the Same Carbon Atom 2.2. Dehalogenation Followed by Intramolecular C-C Coupling 2.3. Dehalogenation Followed by Intermolecular C-C Coupling 2.4. Dehalogenation Followed by Radical Rearrangements or Fragmentation 2.5. Dehalogenation at Heteroatoms 3. Cleavage of C-O, C-S, C-Se, C-Te Bonds 3.1. Deoxygenation 3.2. Desulfuration 3.3. Deselenation and Detelluration 4. Cleavage of C-N Bonds 4.1. Deamination 4.2. Denitration 5. Decarboxylation 6. Addition to C- C Double and Triple Bonds 7. Addition to Carbonyl and Other C=X Groups 8. Miscellaneous Uses 9. Preparation of Tri-n-butyltin Hydride (Deuteride, Tritide), and Work-up Procedure