 Not shown are additional equilibria wherein various intermediates coordinate to additional phosphine ligands at various stages in the catalytic cycle.For chelating ligands, the monophosphine palladium species is not formed; oxidative addition, amide formation and reductive elimination occur from L2Pd complexes.The Hartwig group found that "reductive elimination can occur from either a four-coordinate bisphosphine or three-coordinate monophosphine arylpalladium amido complex.