A SYNTHETIC PATHWAY TO ARYLSILYL(SILYL)ARENES - SELECTIVE SI-C CLEAVAGE IN BIS(ARYLSILYL) ARENES WITH TRIFLIC ACID

Bis(arylsilyl)arenes such as bis(p-tolylsilyl)benzene and bis(p-anisyl silyl)naphthalene are available from in situ Grignard reactions of the corresponding haloarenes, arylchlorosilanes and magnesium in tetrahyd rofuran. Treatment of these products with one equivalent of trifluorom ethanesulfonic (triflic) acid at low temperatures leads to arylsilyl ( trifluoromethylsulfonatosilyl)arenes, which can be converted into aryl silyl(silyl)arenes using LiAlH4. The regioselectivity of the Si-C clea vage is surprisingly high. Any of the first dearylation steps is faste r then the consecutive steps. Ortho, meta and para substituted p-tolyl silyl(silyl) benzene 1,4-dibromo-2-(p-tolylsilyl)-5-(silyl)benzene, an d 1-(p-anisylsilyl)-8-(silyl)naphthalene have thus been obtained in go od to moderate yields. These compounds can serve as starting materials for monofunctional arylsilanes with a tailored structure. The crystal structure of 1-(p-anisylsilyl)-8-(silyl)naphthalene has been determin ed by single crystal X-ray diffraction.