A short summary of the older literature

Preparative Use of Cyanoacetylenes 2.2.2.1 A Short Summary of the Older Literature 

In their review on cyanocarbon and polycyano compounds Ciganek et al. [11 a] wrote in 1970 Although their [i.e., the cyanoacetylenes] physical properties have received considerable attention, reports on the chemistry of these compounds are not as abundant as might be expected in view of their high reactivity . For nearly a quarter of a century this situation has not changed very much in fact, it was one of the reasons why we began our own work in this area. 

Among the classical (summarized in [11]) reactions of cyanoacetylenes (salt and n-complex formation, nucleophilic addition of, inter alia, amines and alcohols, Diels-Alder additions with 2 (see Section 2.22.2), addition of halogens and hydrogen halides, etc.) their polymerization might deserve a second look since the products formed - polyacetylenes - have attracted much attention during the last two decades. Thus 1, several of its derivatives, and 2 have been polymerized with anionic initiators (triethylamine, sodiiun cyanide, butyllithium) to give black, low-molecular-weight polymers claimed to have structures like 33 [38-40], which is obtained from 2 by treatment with butyllithium. 

A structurally related compound, the stable alkylidene-l,6-diphosphorane 35, has been obtained by treating 2 with triphenylphosphine, with the betaine 34 postulated as an intermediate in this process. The trimerization is accompanied by the formation of polymerized acetylene of unknown structure [41, 42] [Eq. (10)]. 

2 Novel Cycloadditions with Cyanoacetyienes - Simple and Efficient Methods for the Construction of Complex Carbon Frameworks 

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