Azaindoles constitute essential subunits in many pharmaceutically important drug substances. 1 In contrast to a vast array of methods for indole synthesis, 2 there are a limited number of methodologies available for azaindole formation. 3 The often employed method involves a Sonogashira coupling of a terminal alkyne with 4-tert-butoxycarbonylamino-3-iodopyridine followed by deprotection/cyclization in situ or in a separate step. 4 Palladium-catalyzed ...