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Amide reduction is a reaction in organic synthesis where an amide is reduced to either an amine or an ... and so does hydrosilylation with a suitable catalyst. References
In organic chemistry, carbonyl reduction is the conversion of any carbonyl group, usually to an alcohol. It is a common transformation that is practiced in many ways. [1] Ketones, aldehydes, carboxylic acids, esters, amides, and acid halides - some of the most pervasive functional groups, -comprise carbonyl compounds.
These hydrides facilitate the reduction of imines or iminium ions—key intermediates in reductive amination—into secondary or tertiary amines. This reaction typically occurs under mild conditions with excellent selectivity, which often makes H 2 /Pd the first choice for synthesizing amines in pharmaceuticals and fine chemicals.
Nitrogen derivates such as amides, nitriles, imines, and most other organonitrogen compounds are reduced to the corresponding amines. Nitroarenes can be converted to azoxyarenes, azoarenes, or hydroazoarenes, depending on the reaction conditions. [1] Some common functional group reductions using SMEAH can be found below:
Amide reduction: Amines, aldehydes Reagent: lithium aluminium hydride followed by hydrolysis Vilsmeier–Haack reaction: Aldehyde (via imine) POCl 3, aromatic substrate, formamide Bischler–Napieralski reaction: Cyclic aryl imine: POCl 3, SOCl 2, etc. Tautomeric chlorination: Imidoyl chloride: Oxophilic halogenating agents, e.g. COCl 2 or SOCl 2
Nahm and Weinreb also reported the synthesis of aldehydes by reduction of the amide with an excess of lithium aluminum hydride (see amide reduction). The Weinreb–Nahm ketone synthesis. The major advantage of this method over addition of organometallic reagents to more typical acyl compounds is that it avoids the common problem of over-addition.
The amide will serve as a nucleophile for the cyclization forming the azlactone 4. Deprotonation and acylation of the azlactone forms the key carbon-carbon bond. Subsequent ring-opening of 6 and decarboxylation give the final keto-amide product. [9] [10] The mechanism of the Dakin-West reaction
Chiral Lewis acid catalysts have been given interests as they could activate the electron-withdrawing group in an enantioselective manner. Chiral cationic oxazaborolidinium catalysts were shown to be effective in the three-component coupling of α,β-acetylenic esters, aldehydes, and trimethylsilyl iodide (50-99% yield, 62-94% ee).