Synthesis of trialkyl[60]fullerene C60(CH2SiMe3)3H and its potassium and rhodium(I) complexes

The reaction of [60]fullerene with Me3SiCH2MgCl in 1,2-Cl2C6H4/THF (1/1) under dry air afforded a bis-alkyl adduct, C60(CH2SiMe3)2 (1), in 54% yield. Treatment of 1 with Me3SiCH2MgCl in THF under argon then afforded a trialkyl[60]fullerene, C60(CH2SiMe3)3H (2), in 37% yield. Further treatment of 2 with KOtBu gave a potassium salt, [K(thf)n][C60(CH2SiMe3)3] (3), which was then converted to a Cs-symmetric Rh(I) complex, Rh[η5-C60(CH2SiMe3)3](1,5-cyclooctadiene) (4), in 91% yield.