Synthesis and Reactions of Pd II Complexes with Aryl, Aroyl, and Iminoaroyl Ligands – Insertion of CO and RNC into the Pd–Ar Bond and Intermolecular Coupling of the Ligands

The arylpalladium(II) complexes [PdIAr(bpy)] (Ar = Ph, C 6 H 3 ‐3,5‐Me 2 , C 6 H 4 ‐4‐OMe, C 6 H 4 ‐2‐OMe, C 6 H 4 ‐4‐C 6 H 4 ‐4‐I, 1‐naphthyl; bpy = 2,2′‐bipyridine) undergo insertion of CO and CNR (R = t Bu, C 6 H 3 ‐2,6‐Me 2 ) into the Pd–aryl bond to produce [PdI(COAr)(bpy)] and [PdI{C(=N–R)Ar}(bpy)]. The dinuclear complex [C 6 H 3 ‐3,5‐{(OCH 2 CH 2 ) 2 C 6 H 4 ‐3‐PdI(bpy)} 2 ] is synthesized by the oxidative addition reaction of 1,3‐bis[(3‐iodophenyl)‐1,4,7‐trioxaheptyl]benzene to [Pd(dba) 2 ] (dba = dibenzylideneacetone). The addition of AgBF 4 to the arylpalladium(II) complexes [PdIAr(bpy)] (Ar = C 6 H 4 ‐4‐OMe, C 6 H 4 ‐2‐OMe, 1‐naphthyl) produces the intermolecular coupling products of the aryl ligands, Ar–Ar. The reactions of AgBF 4 with the aroylpalladium(II) complexes [PdI(COAr)(bpy)] (Ar = C 6 H 3 ‐3,5‐Me 2 , C 6 H 4 ‐2‐OMe) result in decarbonylation and intermolecular coupling of the ligands to yield the diarylketones. The iminoaroylpalladium(II) complex [PdI{C(=N t Bu)C 6 H 3 ‐3,5‐Me 2 }(bpy)] undergoes hydrolysis of the ligand to yield t BuNHCO(C 6 H 3 ‐3,5‐Me 2 ). The addition of AgBF 4 to the dinuclear complex [C 6 H 3 ‐3,5‐{(OCH 2 CH 2 ) 2 C 6 H 4 ‐3‐PdI(bpy)} 2 ] yields a mixture of the cyclic oligomers cyclo ‐[C 6 H 3 ‐3,5‐{(OCH 2 CH 2 ) 2 C 6 H 4 ‐3‐} 2 ] n ( n = 1–4) by inter‐ and intramolecular coupling of the aryl ligands.