Facile C-H Bond Metathesis Mediated by a Stannylene.

The diarylstannylene, :Sn(Ar iPr4)2 (Ar iPr4 = C6H3-2,6-(C6H3-2,6- iPr2)2), undergoes C-H metathesis with toluene, m-xylene, or mesitylene in solutions of these solvents at 80 °C. The products, [Ar iPr4Sn(CH2Ar)]2 (Aryl=C6H5 (1a), C6H4-3-Me (1b), C6H3-3,5-Me2(1c)) were characterized via 1H, 13C and 119Sn NMR, UV-vis and IR spectroscopy, and by X-ray crystallography for 1a and 1b. A stoichiometric amount of the arene, Ar iPr4H, was also produced in these reactions. The use of EPR spectroscopy indicated the presence of a new type of one-coordinate, tin-centered radical, :ṠnAr iPr4, resulting from Sn-C bond cleavage in Sn(Ar iPr4)2.