Selective benzylic C-H activation of solvent toluene and m-xylene by an iron-tin cluster complex: Fe-2(mu-SnBu2t)(2)(CO)(8)

The bimetallic cluster complex Fe-2(mu-SnBu2t)(2)(CO)(8), 1, selectively activates the benzylic C-H bond in solvent toluene at reflux conditions to afford the complex Fe-2[mu-SnBut(CH2Ph)](2)(CO)(8), 3, where two of the But groups in 1 have been replaced with benzyl groups. Similarly 1 also activates the benzylic C-H bond in solvent m-xylene to yield complexes Fe-2[mu-SnBut(m-CH2PhMe)](2)(CO)(8), 4, Fe-2[mu-SnBut(m-CH2PhMe)][mu-Sn(m-CH2PhMe)(2)](CO)(8), 5, and Fe-2[mu-Sn(m-CH2PhMe)(2)](2)(CO)(8), 6, where two, three and four of the Bu-t groups in 1 have been replaced by m-tolyl groups, respectively. A mechanism based on a radical pathway is proposed for the C-H activation by 1. (c) 2009 Elsevier B.V. All rights reserved.