Nitriles interconversions

Scheme 9.31 Interconversion of primary amide and nitrile groups.

This contribution reviews recent results on [Si(Pc)0]n (Pc = phthalocyaninato) solid state electrochemistry and the structural interconversions that accompany electrochemical doping/undoping processes. In aceto-nitrile/(a-Bu)4N+BF4, it is found that a significant overpotential accompanies initial oxidation of as-polymerized [Si(Pc)0]n. This can be associated with an ortho rhomb ic- te tr agonal structural transformation. 

Furazan- and furoxan-carboxylic acids are thermally and hydrolytically unstable decomposing to a-(hydroxyimino)nitriles, but their amide, ester, halide, and nitrile derivatives are readily accessible and all undergo the expected functional group interconversions. Dicyanofuroxan reacts with hydroxylamine to give the fused oxazino compound (63) and the pyridazino analogue (64) is similarly formed with hydrazine <82H(19)1063>. 

Much work has been done since the early 1980s on the detailed investigation of the azirine-nitrile ylide interconversion using pulsed-laser photolysis. Thus the azirines 103 (R =R =Ph, R =H R =Me, R = R =Ph R = p-napthyl, R = Me, R = H), on irradiation in isooctane, gave intense long-hved absorptions (250-400 nm) attributed to the nitrile ylides 104 (44). Quenching studies with electon-deficient alkenes led to the determination of absolute rate constants that were similar to those reported earlier for steady-state trapping experiments. The nitrile ylide-olefin reactions are discussed in more detail in Section 7.3.1. 

The chroman ring system is stable to organometallic reagents, for example in the formation of the tertiary alcohol (690) in high yield (63HCA650), and to the usual interconversion of carboxylic acid, acyl chloride, carboxamide and nitrile. 

Other 2-thiazolines, on irradiation in acetonitrile, undergo fragmentation with the formation of the corresponding nitrile and thiiran.142 A thiiran (167) was also obtained on irradiation of the 1,3-oxathiole (168),143 and the allylic biradical (169) has been proposed as an intermediate in the photochemically induced interconversion of the cyclobutenes (170 and 171).144 Surprisingly,... 

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