Retraction notice to “trans-Tetrakis(pyridine)dichloroiron(II) as catalyst for Suzuki cross-coupling in ethanol and water” [Tetrahedron Lett. 49 (2008) 6679]

RETRACTED: trans-Tetrakis(pyridine)dichloroiron(II) as catalyst for Suzuki cross-coupling in ethanol and water

Aryl bromides can be coupled with phenylboronic acid in moderate to excellent yields using a transtetrakis(pyridine)dichloroiron(II) catalyst. The Suzuki–Miyaura reaction can be carried out under air in ethanol and aqueous ethanol with low catalyst loading. Addition of TBAB dramatically increases the yields in aqueous ethanol or in water. trans-Tetrakis(pyridine)dichloroiron(II) offers an environmental and less expensive method for the synthesis of biaryl compounds. This is the first example of an iron– pyridine catalyst for Suzuki cross-coupling.

Synthesis of Chlorinated Biphenyls by Suzuki Cross-Coupling Using Diamine or Diimine-Palladium Complexes

Several novel diimines (Salen-type ligands) 2a–2i and their reduced diamine counterparts 3b,3d–3g and 3i form complexes 4a–4i, 5b,5d–5g, and 5i with PdCl2 in DMF or methanol. Using 1 mol-% of the isolated complexes 4e and 5f many polychlorinated biphenyls (PCBs) can be prepared in moderate to excellent yields according to the Suzuki crosscoupling protocol with contact to air. Several 4-acetylbiphen