Synthesis and Reactivity of 7-Azaindoles (1H-Pyrrolo(2,3-b)pyridine)

The results of research into the chemistry of 7-azaindole during the last twenty years are presented. New synthetic methods for the 7-azaindole structures are developed including palladium-catalysed cross-coupling reactions. Reactivity of 3-formyl-, 3-halogeno- and 2-lithio-7-azaindole derivatives is reported. Functionalisation of the pyridine ring via the N-oxide is also described. In the last part, biological activity of various 7-azaindole derivatives is briefly indicated.