Hydrocyanation is important due to the versatility of alkyl nitriles (RCN), which are important intermediates for the syntheses of amides, amines, carboxylic acids, and ester compounds. The most popular industrial usage of nickel-catalyzed hydrocyanation is for adiponitrile (NC–(CH2)4–CN) synthesis from 1,3–butadiene (CH2=CH–CH=CH2). Adiponitrile is a precursor to hexamethylenediamine (H2N–(CH2)6–NH2), which is used for the production of certain kinds of Nylon. The DuPont ADN process to give adiponitrile is shown below:
This process consists of three steps: hydrocyanation of butadiene to a mixture of 2-methyl-3-butenenitrile (2M3BM) and 3-pentenenitrile (3PN), an isomerization step from 2M3BM (not desired) to 3PN and a second hydrocyanation (aided by a Lewis acid cocatalyst such as aluminium trichloride or triphenylboron) to adiponitrile.
Naproxen, an anti-inflammatory drug, utilizes an asymmetric enantioselective hydrocyanation of vinylnaphthalene from a phosphinite(OPR2) ligand, L .The enantioselectivity of this reaction is important because only the S enantiomer is medicinally desirable, whereas the R enantiomer produces harmful health effects. This reaction can produce the S enantiomer with > 90% selectivity. Upon recrystallization of the crude product, the optically pure nitrile can be attained.
Read more about this topic: Hydrocyanation
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