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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 [ 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 ]
2 R-C≡N + 4 H 2 → (R-CH 2) 2 NH + NH 3 3 R-C≡N + 6 H 2 → (R-CH 2) 3 N + 2 NH 3. Such reactions proceed via enamine intermediates. [8] The most important reaction condition for selective primary amine production is catalyst choice. [1] Other important factors include solvent choice, solution pH, steric effects, temperature, and the ...
Cyclohexylamine is produced by two routes, the main one being the complete hydrogenation of aniline using some cobalt- or nickel-based catalysts: [4] C 6 H 5 NH 2 + 3 H 2 → C 6 H 11 NH 2 It is also prepared by alkylation of ammonia using cyclohexanol .
[6] [7] According to McQuade, the reaction between methyl acrylate and p-nitrobenzaldehyde is second-order relative to the aldehyde. Moreover, it showed a significant kinetic isotope effect for the acrylate's α-hydrogen (5.2 in DMSO, but ≥2 in all solvents), which would imply that proton abstraction is the rate-determining step.
The intermediate imine can be isolated or reacted in-situ with a suitable reducing agent (e.g., sodium borohydride) to produce the amine product. [2] Intramolecular reductive amination can also occur to afford a cyclic amine product if the amine and carbonyl are on the same molecule of starting material. [4]
The Béchamp reduction (or Béchamp process) is a chemical reaction that converts aromatic nitro compounds to their corresponding anilines using iron as the reductant: [1] 4 C 6 H 5 NO 2 + 9 Fe + 4 H 2 O → 4 C 6 H 5 NH 2 + 3 Fe 3 O 4. This reaction was once a major route to aniline, but catalytic hydrogenation is the preferred method. [2]
The Birch reduction is an organic reaction that is used to convert arenes to 1,4-cyclohexadienes.The reaction is named after the Australian chemist Arthur Birch and involves the organic reduction of aromatic rings in an amine solvent (traditionally liquid ammonia) with an alkali metal (traditionally sodium) and a proton source (traditionally an alcohol).