202352-04-3Relevant academic research and scientific papers
An aryl exchange reaction with full retention of configuration of the complexes: Mechanism of the aryl exchange between [PdR2L2] complexes in chloroform (R = pentahalophenyl, L = thioether)
Casado, Arturo L.,Casares, Juan A.,Espinet, Pablo
, p. 5730 - 5736 (2008/10/08)
The complexes [Pd(3,5-C6Cl2F3)2L2] and [Pd(C6F5)2L2] (L = SC4H8 (tht), or SMe2) react in CCl3D to give a mixture also containing the heteroaryl products [Pd(3,5-C6Cl2F3)(C6F 5)L2], whereas for L = PPh3, AsPh3, 2-picoline, 4-picoline, or 1/2COD, this exchange is not observed. The 19F NMR kinetic study supports that the scrambling of the aryl groups takes place with retention of configuration at both Pd centers via a triply-bridged binuclear activated complex [L(C6Cl2F3)Pd(μ-C6Cl 2F3)(μ-C6F5)(μ-L)Pd(C 6F5)L]?. The aryl double bridge is supported by a bridging S-donor ligand facilitating an otherwise difficult exchange (not observed for other weak L ligands, such as picolines, lacking a second lone pair). This constitutes the first reported example of reversible migration of σ-C-bonded groups between bis-organo Pd(II) complexes proceeding without cis-trans isomerization. The isomerization process is also observed, occurring at a much slower rate.
