Scheme 5 details the formation of major side-products 4a (main cycle, decoordination from Pd II intermediate IV), 5a, 6a and 7a. Pentacycle 7a is thought to arise through a formal oxidative C-H activation of phenanthridinone 2a. Thus, reaction of Pd(dppe)Br2 VIII with 2a would involve formation of Pd II intermediate IX (loss of HBr). Cyclopalladation, with loss of HBr 41 would give 6-membered ring palladacycle X. Finally, reductive elimination forms 7a. The appearance of Pd(dppe)Br2 VIII in our stoichiometric Pd experiments supports this proposal. The association of protodebrominated product 9a with the formation of 7a (revealed by the Heat Map analysis) suggests that 1a is an oxidant in this competing catalytic cycle. Organohalides acting as oxidants for Pd 0 →Pd II is known. The heat map correlation of side-product 6a with 2a allows us to propose that a C-H activation process involving phenanthridinone 2a and Pd II oxidative addition intermediate II is likely, giving complex XI (detailed steps not given). Subsequent reductive elimination regenerates Pd 0 catalyst species I, releasing compound 6a. Alternatively, Catellani et al. has suggested that compounds similar to 6 could arise by intramolecular cyclopalladation, followed by coupling with 1a and ipso-substitution. The heat map analysis revealed a correlation between 5a, 13a and 16a. We propose that 5a arises from C-H activation in IV to form XII, followed by reductive elimination. Porée 8e et al. found that compounds like 5 dominated under reaction conditions in which bromine-carbonate exchange and hence, rotation around the biaryl axis, is disfavored. We acknowledge that 5a could be formed by reaction of urea 3a with product 2a, for which the heat map analysis shows a strong positive correlation. Hydrolysis of 4a likely occurs at Pd II , thus from intermediate IV products carboxylic acid 13a and aniline 16a are formed.