A wide range of palladium catalysed regio-and stereo-specific 5-, 6-and 7-exo-dig mono-, bis-and tris-cyclisation processes of aryl and vinyl halides and allylic acetates are described. The mono-and bis-cyclisation processes terminate in hydride capture from piperidineformic acid or sodium formate. Addition of Tl2CO3 results in alkyne-allene isomerisation and leads, after cyclisation, to 1, 3-dienes which give Diels-Alder adducts in good yield.