Catalytic Semihydrogenation of the Triple Bond

This review surveys the various catalysts used for the semihydrogenation process. For each of these the bond selectivity, stereoselectivity, and some examples of its synthetic utility are presented. 1. Palladium Catalysts for Isolated Triple Bonds 1.1. Bond Selectivity 1.2. Stereoselectivity 1.3. Use in Synthesis 2. Palladium Catalysts for Conjugated Triple Bonds 2.1. Bond Selectivity 2.2. Stereoselectivity 2.3. Conjugation to Aldehyde or Ketone Groups 2.4. Use in Synthesis 3. Nickel Catalysts 3.1. Bond Selectivity 3.2. Stereoselectivity 3.3. Use in Synthesis 4. Miscellaneous Catalysts 4.1. Raney Iron 4.2. Rhodium 4.3. Platinum 4.4.