Reduction of benzonitriles

Benzaldehyde, by condensation of phenyllithium with 1,1,3,3-tetra-methylbutyl isonitrile, 51,38 by reduction of benzonitrile with Raney nickel alloy, 51,22 BENZALDEHYDE, 3,4,5-TRIMETH-OXY-, 51,8... 

Voltammetric data for the reduction of benzonitrile (BN) in iV,iV-dimethylformamide as a function of i fa... 

Experimental data for the reduction of benzonitrile in lV,N-dimethyl-formamide (DMF)—Bu4NBF4 (0.1 M) are given in Table 4 and the results of the two correlation methods are summarized in Tables 5 and 6. This system will be discussed in the section dealing with heterogeneous kinetics. 

The crude Na[Zn2(CH3)2H3] solution in THF may be used as a reducing agent.4 Like lithium tetrahydridoaluminate(l —), the zinc reagent reduces aliphatic ketones and esters to the corresponding alcohols and aliphatic nitriles to amines. However, of the two, the zinc compound is a somewhat milder reducing agent as shown by the reduction of benzonitrile to the corresponding imine under conditions in which lithium tetrahydrido-aluminate(l —) yields the amine. 

Benjfylamine (2), which behaves as an aliphatic amine, may be prepared by the reduction of benzonitrile or benzaldoxime (Scheme 8.10). 

Chiral N-borylimine 65 generated in situ by reduction of benzonitrile 63 with di-isopinocamphenylborane 64 reacted with butyllithiiun to give the adduct 66 with 24% ee in 71 % yield (Scheme 19) [56]. 

N-Sitylimine 89 in ether at -78°C was asymmetrically alkylated with butyl-Uthium in the presence of the diUthium alkoxide of the chiral diol 93 (76%, 62% ee) (Scheme 27) [76]. Addition of the preformed (-)-sparteine (19)-BuLi complex to benzaldehyde N-diisobutylaluminoimine 90, prepared in situ from partial reduction of benzonitrile with diisobutylaluminum hydride, in pentane at -78°C gave the primary amine 92 in good ee (70% yield, 74% ee) [77]. The use of polymer-supported amino alcohol 94 in THF at -78°C allows the asymmetric alkylation of an M-borylimine 91 to give the primary amine 92 with 44% ee [77]. 

The normalized potential LSV is based on a direct comparison of normalized currents, = I/Ip at normalized potentials, E = E —Ep/j. The normalized experimental data are compared with theoretical ones. The comparison of a reversible wave with the Nernstian data (see Appendix G) gives the correlation coefficient 1.0. In the case of an irreversible (or quasi-reversible) process the parameters of the electrode process, k° and can be estimated using working curves for different combinations of these quantities. For the reduction of benzonitrile in DMF at a mercury electrode the working curves were best fitted with ranging from 0.47 to 0.50 and corresponding k° values (5.8-4.9) X lO- ms- [126]. 

Reaction conditions were optimized for the reduction of benzonitrile la to benzaldehyde 2a. These optimized reaction conditions were used successfully for other aromatic nitriles [44]. 

Imamura K, Yoshikawa T, Nakanishi K, Hashimoto K, Kominami H (2013) Photocatalytic reduction of benzonitrile to benzylamine in aqueous suspensions of palladium-loaded titanium (IV) oxide. Chem Commun 49 10911-10913... 

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