AbstractsChemistry

Palladium-mediated carbon-earbon (and carbon-heteroatom) bond formation! is to an increasing extent playing a vital role in synthetic organic chemistry. The chemistry is usually performed under mild conditions, with the organopal1adium intermediates being formed in situ from inorganic palladium salts or complexes, and has good tolerance of functionality on the substrates. The palladium mediator may be present in the reaction in amounts ranging from stoichiometric to catalytic. Reactions requiring stoichiometric amounts of palladium may appear to be inherently uneconomical. Palladium, however, may be easily recovered in most cases, and may be converted into salts useful for catalysis, effectively offsetting the initial expense. 2 The use of polymer-bound palladium catalysts! has also been shown to be a viable method of palladium recovery. Palladium may form a- or 1r-eomplexes with organic compounds and, as with many other transition-metal complexes, a-palladium complexes are generally only stable in the presence of select ligands. Arylphosphines are most commonly used, and of these triphenylphosphine is the ligand of choice for its availability and low cost...