METALATION OF ALIPHATIC CARBON-ATOMS .6. REACTIONS OF 2-PIVALOYLPYRIDINE WITH PALLADIUM(II) ACETATE RESULTING IN CYCLOPALLADATION AND NUCLEOPHILIC ATTACKS ON CARBONYL CARBON

The reaction of 2-pivaloylpyridine and palladium(II) acetate in acetic acid at 90-95-degrees-C gives a binuclear, six-membered cyclopalladated complex, [{Pd[CH2CMe2C(= O)C5H4N](mu-MeCO2)}2]. Treatment of this complex with lithium chloride affords the chloro-bridged analogue, [{Pd[CH2CMe2C(= O)C5H4N](mu-Cl)}2], which is converted into the corresponding mononuclear complexes by reactions with 3,5-dimethylpyridine and thallium(I) acetylacetonate. In refluxing methanol this reaction yields a new 1-methoxy-2,2-dimethyl-1-(2-pyridyl)propoxo-N,O type complex, [Pd{OC(OMe)((t)Bu)C5H4N}2]. Palladium(II) acetate reacts with 2-pivaloylpyridine in the presence of water in benzene to produce [{Pd[OC(OH)((t)BU)C5H4N](mu-MeCO2)}2] and [Pd{OC(OH)((t)BU)C5H4N}2].