ja064935c_si_008.cif (25.83 kB)

Facile Ar−CF3 Bond Formation at Pd. Strikingly Different Outcomes of Reductive Elimination from [(Ph3P)2Pd(CF3)Ph] and [(Xantphos)Pd(CF3)Ph]

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posted on 04.10.2006, 00:00 by Vladimir V. Grushin, William J. Marshall
Facile and highly selective perfluoroalkyl−aryl reductive elimination from a metal center (Pd) has been demonstrated for the first time. At temperatures as low as 50−80 °C, [(Xantphos)Pd(Ph)CF3] undergoes remarkably clean decomposition to produce CF3Ph in high yield and selectivity. In contrast, analogous trifluoromethylpalladium aryls stabilized by rigid cis-chelating ligands such as dppe are completely unreactive at temperatures up to 130−140 °C. Decomposition of [(Ph3P)2Pd(Ph)CF3] in the presence of PhI in benzene at 60 °C does not produce PhCF3 but rather leads to [(Ph3P)2Pd(Ph)I] and [Ph4P]+[(Ph3P)Pd(CF3)3]- in a 2:1 ratio with high selectivity.