The review surveys the reactions of electron-deficient azaaromatic compounds with mono- and bifunctional nucleophilies in which a nucleophilic attack at the unsubstituted CH carbon of an aromatic ring is one of the key steps. Use of the SNH methodology for the synthesis of fused heterocyclic systems by means of nucleophilic addition –addition AN–AN, addition –substitution of hydrogen AN–SNH, tandem substitution of hydrogen SNH–SNH, and other strategies will be discussed. Intramolecular SNH reactions will also be considered as effective synthetic tools to obtain condensed heterocyclic systems.
