Selective and efficient access to ortho, meta and para ring-substituted phenylacetylene derivatives R-[C C-C6H4](x)-Y (Y=H, NO2, CN, I, NH2)

ortho, meta and para isomers of iodo and amino ring-substituted phenylacetylene as well as rod-like arylacetylene derivatives were prepared by a simple synthetic route involving three consecutive reactions: the palladium-catalysed carbon-carbon bond formation, the Sandmeyer reaction and thr desilylation of die protected trimethylsilylalkynes. (C) 1997 Elsevier Science Ltd.