Selective benzylic C–H activation of solvent toluene and m-xylene by an iron–tin cluster complex: Fe2(μ-SnBu2t)2(CO)8

The bimetallic cluster complex Fe2(μ-SnBu2t)2(CO)8, 1, selectively activates the benzylic C–H bond in solvent toluene at reflux conditions to afford the complex Fe2[μ-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 Fe2[μ-SnBut(m-CH2PhMe)]2(CO)8, 4, Fe2[μ-SnBut(m-CH2PhMe)][μ-Sn(m-CH2PhMe)2](CO)8, 5, and Fe2[μ-Sn(m-CH2PhMe)2]2(CO)8, 6, where two, three and four of the But groups in 1 have been replaced by m-tolyl groups, respectively.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.

Graphical abstractThe bimetallic cluster Fe2(μ-SnBu2t)2(CO)8, 1, reacts with solvent toluene and m-xylene to yield benzylic C–H activated products, where the But groups in 1 have been replaced by benzyl or m-tolyl groups. A radical mechanism for this reaction is proposed.Figure optionsDownload full-size imageDownload as PowerPoint slide