Pd(0) catalysed bis- and tris-cyclisation reactions involving aryl-or vinyl-iodides and terminating in Tonnai Friedel-Crafts alkylation of aryl and heteroaryl rings occur regio- and stereo-specifically in good yield.
A new, wide ranging, synthetically powerful, catalytic tandem cyclisation-anion capture process is proposed which depends on the rate of cyclisation of an organopalladium specifies (RPdX) onto a proximate alkene or diene being significantly faster than anion exchange and reductive elimination in the sequence RPdX → RPdY → RY + Pd(0). The catalytic cyclisation - anion capture sequence is illustrated