Search results
Results from the WOW.Com Content Network
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 ]
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 ...
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 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 ]
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]
In a similar fashion, the intermediate isocyanate can be trapped by tert-butyl alcohol, yielding the tert-butoxycarbonyl (Boc)-protected amine. The Hofmann Rearrangement also can be used to yield carbamates from α,β - unsaturated or α- hydroxy amides [ 2 ] [ 8 ] or nitriles from α,β- acetylenic amides [ 2 ] [ 9 ] in good yields (≈70%).
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 amine concentration in the absorbent aqueous solution is an important parameter in the design and operation of an amine gas treating process. Depending on which one of the following four amines the unit was designed to use and what gases it was designed to remove, these are some typical amine concentrations, expressed as weight percent of ...