Arynes and heteroarynes

Arynes and heteroarynes are reactive intermediates derived formally by the removal of two adjacent hydrogens from, respectively, a carbocyclic or a heterocyclic aromatic ring. Prototypical examples are benzyne (1) and 3,4-didehydropyridine (2). Since these molecules contain a partial triple bond, they are properly regarded as -ynes and, as will be seen, undergo many reactions typical of that functionality, modified by the inherent strain caused by their nonlinearity. 

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