Synthesis, Isolation, and Characterization of an Organometallic Triiodopalladium(IV) Complex. Quantitative and Regioselective Synthesis of Two C-I Reductive Elimination Products

Iodine and the pincer complex [Pd(O,N,C-L)I], where L is the monoanionic ligand resulting from deprotonation of the acetyl group of the dimethylmonoketal of 2,6-diacetylpyridine, are in equilibrium at low temperatures with the palladium(IV) complex [Pd(O,N,C-L)I-3], which can be isolated at -40 degrees C and characterized by H-1 NMR spectroscopy and X-ray diffraction studies, in spite of its great instability. When the same reaction is carried out at room temperature, a quantitative reductive elimination process occurs, giving L-I, which in the presence of water affords L'1, resulting from hydrolysis of L-I.