Reduction of Nitriles To aldehydes:
The Nitriles can be reduced to aldehydes by Aluminum hydride (AlH).
DIBAL-H (diisobutylaluminum hydride) is generally used for the reduction of Nitriles.
Explanation:
Nitriles can also be reduced to aldehydes.
Reducing agent Diisobutylaluminium hydride, or DIBAL-H, is another commonly used metal hydride. DIBAL-H acts as a proton source, adding a hydride ion to the carbon of the nitrile. The resulting imine is a relatively stable intermediate that can be hydrolyzed to the aldehyde.
DIBAL-H is added in controlled amounts at low temperatures to achieve partial reduction of the nitrile. The aluminum atom in DIBAL acts as a Lewis acid, accepting an electron pair from the nitrile. The nitrile is then reduced by the transfer of a hydride ion to the carbon of the carbon-nitrile triple bond, producing an imine. After a workup with water, the aluminum complex is hydrolyzed to produce the desired aldehyde. Because the hydrolytic workup generates the aldehyde at the end, the nitrile does not undergo over-reduction.