Chemo- and regio-specific palladium catalysed four component cascade processes, involving formation of 4 new bonds, initiated by oxidative addition of Pd(0) with aryl/heteroaryl iodides followed by sequential incorporation of CO(1atm), allene (1atm) and an S- or N-nucleophile [PhSO2-or (RNTs)(-)] occur in good to excellent yield at 50 degrees C. (C) 1997 Elsevier Science Ltd.