Nitrile compounds triple-bond systems

Dehydration of primary nitro compounds (Mukaiyama reaction)12 affords nitrile oxides, which may dimerize to yield furoxans, or otherwise be trapped by suitable dipolarophiles such as double or triple bond systems, leading to the formation of various heterocyclic systems, 5.13 The latter have been used for further derivatization in the heterocyclic series, or in "return" as precursors of acyclic products after ring cleavage,7d-14 for example, 1,3-amino alcohols 6 or (J-hydroxycarbonyl compounds, 9. 

One of die most popular reactions in organic chemistry is dissolving metal reductions [1-3], Two systems are frequently used - sodium dissolved in ammonia with alcohol and lithium dissolved in alkylamines [4]. Although calcium is seldom used, it has been successfully applied to the reduction of a variety of compounds and functional groups [5], including aromatic hydrocarbons, carbon-carbon double and triple bonds, benzyl ethers, allyl ethers, epoxides, esters, aliphatic nitriles, dithianes, als well as thiophenyl and sulfonyl groups. 

The areas covered by this chapter deal with the photochemistry and radiation chemistry of triply bonded systems. The definition of a system with a triple bond is fairly loose and the review will deal with compounds which contain the following functionalities alkynes, nitriles, diazo compounds, diazonium salts and azides. The photochemical reactivity of these compounds has been reviewed extensively This review is not intended to be encyclopaedic but will highlight some of the areas currently of interest. 

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