Cyclometalation of Arylazo Compounds. Part 2. Regioselectivity of the Cyclopalladation of Some Substituted 1-Arylazonaphthalenes

Article abstract of DOI:10.1002/hlca.19820650409

A variety of cyclopalladated 1-arylazonaphthalenes is described, where ortho-palladation occurs at C(2) in the naphthyl ring or at C(2' or 6') in the phenyl moiety.Two examples of peri-cyclopalladation at C(8) in the naphthyl ring are presented.The electronic and steric influences of substituents at either arene moiety on the relative basicities of the azo-N-atoms and the relative nucleophilicities of the potential palladation sites C(2), C(2' or 6'), and C(8) are discussed qualitatively in order to rationalize the observed regioselectivity.