Reactivity of 2,6‐Dihalophenyl Lithium Reagents Towards Chlorosilanes. Synthesis and Structure of 2,3‐ and 2,6‐Dihalophenyl(di‐)silanes

The reaction of 2,6‐dihalophenyllithium 2,6‐X2C6H3Li (X = F, Cl, Br) with the chlorosilanes ClMe2SiSiCl2Me, SiCl4, and HSiCl3 afforded the diaryldisilanes (2,6‐X2C6H3SiMe2)2 [X = F (1a), Cl (1b), Br (1c)] and the diaryl‐ and triarylsilanes (2,6‐X2C6H3)2SiCl2 [X = F (3a), Cl (3a)], (2,3‐Br2C6H3)2SiCl2 (4c), (2,6‐F2C6H3)3SiH (6a), and (2,6‐X2C6H3)2Si(H)Cl [X = Cl (7b), Br (7c)], respectively. The formation of 4c was rationalized on the basis of an equilibrium that exists between the aryllithium isomers 2,6‐Br2C6H3Li and 2,3‐Br2C6H3Li. Reduction of 3a, 3b, 4c, 7b, and 7c using LiAlH4 provided the diarylsilanes (2,6‐X2C6H3)2SiH2 [X = F (2a), Cl (2b), Br (2c)] and (2,3‐Br2C6H3)2SiH2 (5c), respectively. The products were characterized by multinuclear NMR spectroscopy (1H, 13C, 19F, 29Si) and in case of 1a, 1b, 2a, 2b, 2c, 5c, and 6a also by X‐ray crystallography.