Aminolysis of nitriles

Lastly, an unexpected aminolysis of nitriles catalyzed by the nickel (II) bromide, which affords an interesting new way to amides, is described. 

As an unexpected result of our investigations on the arylation of amines, a new catalysis with nickel complexes was pointed out for the aminolysis of nitriles indeed, in the reaction of the p-bromobenzonitrile with the 4-phenylpyridine in the presence of catalytic amounts of NiBr2, in addition to the expected arylamine, the amide resulting from the aminolysis of the cyano group (and subsequent hydrolysis during the work-up) was isolated (eqn. 8). 

But, till now, to the best of our knowledge, there is no example for the aminolysis of nitriles catalyzed by nickel complexes. 

Trimerization of nitriles, isocyanates, isothiocyanates, imidates, and carbodiimides all lead to symmetrical 2,4,6-trisubstituted 1,3,5-triazines (see Section 6.12.9.5). The use of lanthanide trifluoromethanesulfonate and ammonia as cocatalysts is claimed as a big improvement. The trisaminal of 2,4,6-triformyl-l,3,5-triazine is also useful for further derivatization to unusual structures (see Section 6.12.7.1). Treatment of a 1 1 pyridine/conc. ammonia solution of an aromatic aldehyde with excess Fremy s salt is another development. Separation of the amide coproduct was claimed to be easy. The synthesis fails with aliphatic aldehydes (see Section 6.12.9.5.4). Aminolysis of 2,4,6-triaryl-1,3,5-oxadiazinium salts gives symmetrical 1,3,5-triazines but the reactions are limited in that electron-withdrawing groups in the aromatic rings lead to instability and difficulty in separation of products (see Section 6.12.10.4). 

The ammonolysis of unsaturated carbonyl compounds in the presence of hydrogen is the most exothermic type. Reaction of phenols, alcohols, and halides with ammonia is only slightly exothermic. Aminolysis of alcohols is much more exothermic than the ammonolysis. Reactions of hydrocarbons with ammonia to form nitriles seem to be special cases in that they are extremely endothermic in nature. 

Gd(OTf)3 is prepared by the general method described above. If suspect, then add aqueous triflic acid (50% vA) and proceed as above. It catalyses the aminolysis of epoxides in an extraordinarily efficient manner in aprotic solvents (e.g. toluene, CH2CI2) with complete trans stereoselectivity and high regioselectivity [Chini et al. Tetrahedron Lett 35 433 1994]. It also catalyses the reactions between nitriles and amines to yield a variety of amidines which, depending on the amine, can be used to prepare cyclic amidines, pyrimidines and x-triazines [Forsberg et al. J Org Chem 52 1017 79S7]. It is a water-tolerant Lewis acid used in aldol reactions of silyl enol-ethers and aldehydes in -79-89% yields (see below) [Kobayashi Hachiya J Org Chem 59 3590 1994]. 

A few years after the first publication on acylamino acid thiophenyl esters [4] the peptide research team of the CIBA laboratories in Basel, led by Robert Schwyzer, described a systematic study of the aminolysis of methyl esters substituted with various electron-withdrawing groups [20]. From a series of esters examined with respect to their reaction rates in aminolysis cyanomethyl esters were selected as best suited for peptide synthesis. Cyanomethyl esters were readily prepared through the reaction of acylamino acid salts with chloroaceto-nitrile and they showed satisfactory rates in the acylation of amino acid esters... 

Many of the reactions which have been reported for carbonyl compounds (hydration, alcoholysis, aminolysis, etc.) are also shown by co-ordinated nitrile ligands. The reaction of a nucleophile with a nitrile is a two-stage process, which may involve one or two molecules of the incoming nucleophile (Fig. 4-6). 

Acid derivatives including esters, amides, halides and nitriles are readily accessible. Dicyanofuroxan (72) shows in its reactions some similarities to phthalonitrile (75LA1029) it also provides a source of fused pyridazino- and oxazino-furoxans (73) and (74) via addition with hydrazine and hydroxylamine, respectively (82H(19)1063). The tetronic acid compound (75) yields a hydroxyamide (76) on aminolysis (79S977). 

Bridgehead nitrogen hydantoins have been obtained from imidazole-, pyrrolidine-, and piperidine-2-carboxylates,19 as well as spirohydantoins, such as 15, derived from the aminolysis products of isatincarboxamides.20 Amino nitriles react in a similar manner.1,3,21,22... 

This nitrile aminolysis reaction, involving a nickel catalysis, permits moreover to obtain the synthesis of N,N -disubstituted amidines, the classical methods leading only to the corresponding N-unsubstituted amidines. 

The results are reported of the application of Fourier transform IR spectroscopy to the study of the chemical degradation of a PETP fibre/nitrile mbber composite under consideration for use in an experimental automotive subsystem. It is shown that the mechanism of polyester decomposition responsible for failure is aminolysis. 9 refs. An appendix is included, which presents data for unadulterated and modified PETP samples and describes a successful attempt to identily anomalous broadening of intense bands observed in the spectrum of fibres, where strength is preserved. 21 refs. 

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