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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 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]
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 ...
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]
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]
The catalytic hydrogenation of nitriles is often the most economical route available for the production of primary amines. [3] Catalysts for the reaction often include group 10 metals such as Raney nickel , [ 4 ] [ 5 ] [ 6 ] palladium black , or platinum dioxide . [ 1 ]
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 ]
The hydrogen sulfide is subsequently recovered in an amine treater and finally converted to elemental sulfur in a Claus process unit. In those industries, desulfurization process units are often referred to as hydrodesulfurizers (HDS) or hydrotreaters (HDT). Catalysts are based on molybdenum sulfide containing smaller amounts of cobalt or ...