Cinnolinium salt synthesis from cyclopalladated azobenzene complexes and alkynes

Article abstract of DOI:10.1021/om00154a019

The reactivity of the cyclopalladated azobenzene chloro dimer is greatly enhanced when the chloro ligands are replaced by tetrafluoroborate ion. The disolvated tetrafluoroborate reacts with a variety of disubstituted alkynes under mild conditions to form 2-phenylcinnolinium tetrafluoroborates in moderate to good yields. The reaction will occur thermally with the cyclopalladated dimer, also, but only in modest yields.