Unexpected isolation, and structural characterization, of a β-hydrogen-containing σ-alkylpalladium halide complex in the course of an intramolecular Heck reaction. Synthesis of polycyclic isoquinoline derivativesElectronic supplementary information (ESI) available: Experimental information for compounds 1–7. Crystal data for 5. Fig. SI 1 (possible conformations for the Heck insertion step). See http://www.rsc.org/suppdata/cc/b2/b211856b