Chemo-and regioselectivity of intramolecular Heck reactions are dependent on the type of ligand employed. Six-to eight-membered benzolactams are produced in good yields using PPh3 as ligand. In contrast, a biaryl coupling occurred preferentially under ligandless conditions to form a dihydrophenanthridine product. Conformations of the seven-and eight- membered benzolactams in the solid state were examined by X-ray crystallography.
