Synthesis and Characterization of Post-β-Carbon-Elimination Organopalladium Complexes

A unique family of N,N,π,C-palladacycles are synthesized from 8-aminoquinoline-coupled nopol derivatives through directed 1,2-migratory insertion of in situ generated arylpalladium(II) species followed by β-carbon elimination. These palladacycles have exceptional stability under air and moisture at room temperature, enabling successful isolation and characterization by X-ray crystallography, NMR, and high-resolution mass spectrometry. Computational studies shed light on the facile β-alkyl elimination step and the origins of the high stability of these post-β-carbon-elimination complexes.