Single and Multiple Insertion of Carbon−Carbon Triple Bonds into the Palladium−Aryl Bond of Cationic and Neutral Arylpalladium Complexes with a 2,2‘-Bipyridine Ligand

Dimethyl acetylenedicarboxylate reacts with PdI(C6H3Me2-3,5)(bpy) in the presence of AgBF4, causing rapid insertion of three acetylene molecules into the Pd−C bond to afford (Z = COOMe), whereas a similar reaction without AgBF4 gives the product of a single insertion of the carbon−carbon triple bond, Pd(I)(CZCZC6H3Me2-3,5)(bpy).