| Abstract
| - Air-stable palladium complexes [(t-Bu)2P(OH)]2PdCl2, [(t-Bu)2P(OH)PdCl2]2, and [[(t-Bu)2PO···H···OP(t-Bu)2]PdCl]2 serve as efficient catalysts for a variety of cross-coupling reactions of vinyl andaryl chlorides with arylboronic acids, arylzinc reagents, and thiols to yield the corresponding styrenederivatives, biaryls, and thioethers. 31P NMR and mechanistic studies argue that the phosphinousacid ligands in the complexes can be deprotonated in the presence of a base to yield an electron-rich anionic species, which is likely a catalyst intermediate, and dimeric [[(t-Bu)2PO···H···OP(t-Bu)2]PdCl]2 was isolated and cystallographically characterized. These anionic complexes areanticipated not only to accelerate the rate-determining oxidative addition of aryl chlorides but alsoto stabilize the palladium complexes in the catalytic cycle.
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