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In chemistry, the hydrogenation of carbon–nitrogen double bonds is the addition of the elements of dihydrogen (H 2) across a carbon–nitrogen double bond, forming amines or amine derivatives. [1] Although a variety of general methods have been developed for the enantioselective hydrogenation of ketones, [ 2 ] methods for the hydrogenation of ...
Catalytic hydrogenation using platinum(IV) oxide (PtO 2) [23] or Raney nickel [24] Iron metal in refluxing acetic acid [25] Samarium diiodide [26] Raney nickel, platinum on carbon, or zinc dust and formic acid or ammonium formate [6] α,β-Unsaturated nitro compounds can be reduced to saturated amines by: Catalytic hydrogenation over palladium ...
An example of a homogeneous catalytic system is the reductive amination of ketones done with an iridium catalyst. [20] Homogenous Iridium (III) catalysts have been shown to be effective in the reductive amination of carboxylic acids , which in the past has been more difficult than aldehydes and ketones. [ 16 ]
Useful reagents for this reaction include formic acid with a hydrogenation catalysis [12] or metal hydrides, which are used to add one mol of hydrogen to the nitrile. For example, sodium borohydride reduces nitriles in alcoholic solvents with a CoCl 2 catalyst or Raney nickel .
Catalytic hydrogenation [ edit ] Catalytic hydrogenation can be used to reduce amides to amines ; however, the process often requires high hydrogenation pressures and reaction temperatures to be effective (i.e. often requiring pressures above 197 atm and temperatures exceeding 200 °C). [ 1 ]
For example, reaction between sterically hindered t-butyl acrylate and benzaldehyde with catalytic DABCO in the absence of solvent required 4 weeks to give moderate conversion to the final product. In aprotic solvents, the reaction rate is even slower, although recovery is possible with protic additives (e.g. alcohols and carboxylic acids). [15]
Hydrogenation is a chemical reaction between molecular hydrogen (H 2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically constitutes the addition of pairs of hydrogen atoms to a molecule ...
An imine can be reduced to an amine via hydrogenation for example in a synthesis of m-tolylbenzylamine: [32] Other reducing agents are lithium aluminium hydride and sodium borohydride. [33] The asymmetric reduction of imines has been achieved by hydrosilylation using a rhodium-DIOP catalyst. [34] Many systems have since been investigated. [35] [36]