P-Nitrobenzonitrile

The complete stereoselectivity of the reaction, however, is difficult to reconcile with a two-step process. This earlier controversy, however, has long since been resolved. For example, when considering results of the cycloaddition of p-nitrobenzonitrile oxide with cis- and trani-l,2-dideuterioethylene (111), the experiments clearly established that, within experimental limits of detection, the reaction is > 98% stereoselective. If diradical intermediates were operative, significant scrambling of configuration should be observed in the products. These and other results confirm a concerted mechanism for the 1,3-dipolar cycloaddition reaction (15). 

The kinetics and mechanism of the phosphorus-catalysed dimerization of acrylonitrile to give 1,4-dicyanobut-l-ene and 2,4-dicyanobut-l-ene have been studied.114 The reactions of aryhminodimagnesium (138) with //-substituted p-cyanobenzophenones, l-cyano-9-fluorenenone, o-, m-, and p-dicyanobcnzcnes, and o-, m-, and p-nitrobenzonitriles have been examined.115 The effect of pressure on the reaction of 3 -methyl- l-(4-tolyl)triazene (139) and benzoic acid in chloroform and acetonitrile has been studied.116 The effect of acids on the rate of urethane formation from alcohols and isocyanates in the presence of alkyltin carboxylates has been examined.117 A Hammett a value has been reported for the amidine group N=CHNMe2 and used for the prediction of the basicity of sites in bifunctional amidines.118... 

NH2— —NO2. A first communication notes that trifluoroacetic acid, a very strong acid (pKa 0.3) reacts with aqueous hydrogen peroxide much more iiipidly than formic or acetic acid, and that the equilibrium probably is much more liivorable to the peracid. For oxidation of 0.05 mole of p-aminobenzonitrile to p-nitrobenzonitrile, a solution of peracid is prepared by adding 5.1 ml. (0.2 mole) of... 

The first experiments were reported by Nozik and co-workers, for p-GaP and p-InP liquid junctions [95, 96], In particular, InP was a good candidate, because of its high electron mobility. The authors used p-nitrobenzonitrile (t/redox = -0.86 V (SCE)) as an electron acceptor, because the standard potential of this redox couple occurs 0.44 eV above the conduction band as determined by Mott-Schottky measurements. Photocurrent-potential curves in blank solutions were compared with those of solutions containing nitrobenzonitrile. The observation of increased cathodic photocurrent was reported as evidence for hot electron transfer. 

MILLER-SNYDER Aryl Cyanide Synthesis Synthesis of benzonitriles from aldehydes via oxime ethers in the presence of p-nitrobenzonitrile. Formation of p-cyanophenol fron p-nitrobenzaldoxime and p-nitrobenzonitrile (used as a sometimes recyclable chain carrier) (see 1st edition). 

The choice of nitrile is also important. In general, nitriles with electron withdrawing substituents, such as p-nitrobenzonitrile, tend to increase aldehyde selectivity and yield (Table 1). 

The lower yield of trimerized product from the o-nitrobenzo-nitrile compared to p-nitrobenzonitrile can be accounted for by steric effects. The very hi yield of trimerized product from the p-cyanobenzoic acid mi t have resulted from a reaction in which the p-cyanobenzoic acid itself served as a CO-catalyst. 

---