General method for the preparation of alkyne-functionalized oligopyridine building blocks

A general approach for the synthesis of substituted oligopyridines containing a single alkyne chain comprising one, two or three ethynyl groups, is described. The procedure was used for the synthesis of a large series of alkyne-substituted oligopyridines based on 2,2-bipyridine, 1,10-phennathroline, 2,2':6',2'-terpyridine or 1,8-naphthyridine substrates. Stepwise extension of the acetylene function by Cadiot-Chodkiewicz coupling and alkali-methanolic deprotectio results in the isolation of a family of novel dibutadinyl- and hexadiynyl-oligopyridine compounds.