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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 ...
The factors involved include whether the amine unit is treating raw natural gas or petroleum refinery by-product gases that contain relatively low concentrations of both H 2 S and CO 2 or whether the unit is treating gases with a high percentage of CO 2 such as the offgas from the steam reforming process used in ammonia production or the flue ...
For example, isophorone diamine, a precursor to the polyurethane monomer isophorone diisocyanate, is produced from isophorone nitrile by a tandem nitrile hydrogenation/reductive amination by ammonia, wherein hydrogenation converts both the nitrile into an amine and the imine formed from the aldehyde and ammonia into another amine.
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 ...
[2] 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]
For example, in the three-component coupling of aldehydes, amines, and activated alkenes, the aldehyde reacts with the amine to produce an imine prior to forming the aza-MBH adduct, as in the reaction of aryl aldehydes, diphenylphosphinamide, and methyl vinyl ketone, in the presence of TiCl 4, triphenylphosphine, and triethylamine: [19]
The addition of hydrogen and an amino group (NR 2) using reagents other than the amine HNR 2 is known as a "formal hydroamination" reaction. Although the advantages of atom economy and/or ready available of the nitrogen source are diminished as a result, the greater thermodynamic driving force, as well as ability to tune the aminating reagent ...
2-Picolylamine is an organic compound with the formula H 2 NCH 2 C 5 H 4 N. A colorless liquid, it is a common bidentate ligand and a precursor to more complex multidentate ligands such as tris(2-pyridylmethyl)amine. It is usually prepared by hydrogenation of 2-cyanopyridine.