Syntheses and Structures of Silyl-Group-Containing Hexaalkylated Benzenes

Friedel−Crafts alkylation of vinyldichloromethylsilane to benzene in the presence of aluminum chloride catalyst at room temperature gave hexakis((dichloromethylsilyl)ethyl)benzene ( 1 ) in 56% yield, along with small amounts of less alkylated products. 1 was easily converted to the corresponding compounds, C 6 (CH 2 CH 2 SiMeR 2 ) 6; ( 5 (R = OCH 3 ), 6 (R = H), 7 (R = CH 3 ), 8 (R = vinyl), 9 (R = allyl), 10 (R = ethynyl), and 11 (R = benzyl)) by reaction with the appropriate nucleophilic reagents. The molecular structures of hexakis((methylsilylethyl)benzene ( 6 ) and the solvent adducts of hexakis((trimethylsilyl)ethyl)benzene ( 7 ·2CH 2 Cl 2 ) and hexakis((dibenzylmethylsilyl)ethyl)benzene ( 11 ·2CHCl 3 ) have been determined by X-ray diffraction studies. Each dichloromethane and chloroform molecule formed C−H···aryl hydrogen bonds, one above and one below, to the ring centroid. The distances between the carbon and the ring centroid were 3.469 and 3.466 Å for CH 2 Cl 2 and CHCl 3, respectively.