Amide reduction

Catalytic hydrogenation

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).

Amines from other hydride sources

Reducing agents able to effect this reaction include metal hydrides such as lithium aluminium hydride, or lithium borohydride in mixed solvents of tetrahydrofuran and methanol. :[[File:Reduction of amide.svg|400px|Reduction of amides to amines]] Iron catalysis by triiron dodecacarbonyl in combination with polymethylhydrosiloxane has been reported.

Lawesson's reagent converts amides to thioamides, which then catalytically desulfurize.

Noncatalytic routes to aldehydes

Some amides can be reduced to aldehydes in the Sonn-Müller method, but most routes to aldehydes involve a well-chosen organometallic reductant.

Lithium aluminum hydride reduces an excess of N,N-disubstituted amides to an aldehyde: :R(CO)NRR' + LiAlH4 → RCHO + HNRR' With further reduction the alcohol is obtained.

Schwartz's reagent reduces amides to aldehydes, and so does hydrosilylation with a suitable catalyst.

References

References

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2. {{JerryMarch
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