Transfer hydrogenation
Under transfer hydrogenation refers to the addition of hydrogen (H 2 ) to a molecule , wherein the hydrogen is not from gaseous hydrogen. Transfer hydrogenations are used in industry and in organic synthesis , mostly to avoid the potentially dangerous handling of gaseous hydrogen (H 2 ).
Catalytic transfer hydrogenation
For the catalytic transfer hydrogenation some very active and useful were the catalyst - Complex developed. They are based on complexes of ruthenium or rhodium as the metal center with diamine or phosphine - ligand . Transfer hydrogenation is mostly used in the reduction of ketones to alcohols and imines to amines . The reductions can be stereoselective if the starting material is prochiral. Isopropanol , which is usually also the solvent , usually acts as the hydrogen donor .
Ryōji Noyori was awarded the 2001 Nobel Prize in Chemistry for the asymmetric hydrogenation of β-keto esters with chiral ruthenium- BINAP complexes .
Industrial application
In industrial use, partially hydrogenated aromatics such as tetralin or decalin are mostly used in non-catalytic processes. For example, tetralin was used for thermal hydocracking in carbohydrate hydrogenation at temperatures of around 500 ° C. Today hydrogen is mostly used with the addition of an iron catalyst.
Individual evidence
- ↑ T. Ikariya, K. Murata, R. Noyori: Bifunctional Transition Metal-Based Molecular Catalysts for Asymmetric Syntheses , Org. Biomol. Chem., 2006, volume 4, 393-406.