Synthesis and Characterization of m‐Terphenyl (1,3‐Diphenylbenzene) Compounds Containing Trifluoromethyl Groups

Abstract

AbstractThe bis(silyl)triazene compound 2,6‐(Me3Si)2‐4‐Me‐1‐(NNNC4H8)C6H2 (4) was synthesized by double lithiation/silylation of 2,6‐Br2‐4‐Me‐1‐(NNNC4H8)C6H2 (1). Furthermore, 2,6‐bis[3,5‐(CF3)2‐C6H3]‐4‐Me‐C6H2‐1‐(NNNC4H8)C6H2 derivative 6 can be easily synthesized by a C,C‐bond formation reaction of 1 with the corresponding aryl‐Grignard reagent, i.e., 3,5‐bis[(trifluoromethyl)phenyl]magnesium bromide. Reactions of compound 4 with KI and 6 with I2 afforded in good yields novel phenyl derivatives, 2,6‐(Me3Si)2‐4‐MeC6H2I and 2,6‐bis[3,5‐(CF3)2C6H3]‐4‐MeC6H2I (5 and 7, resp.). On the other hand, the analogous m‐terphenyl 1,3‐diphenylbenzene compound 2,6‐bis[3,5‐(CF3)2C6H3]C6H3I (8) could be obtained in moderate yield from the reaction of (2,6‐dichlorophenyl)lithium and 2 equiv. of aryl‐Grignard reagent, followed by the reaction with I2. Different attempts to introduce the tBu (Me3C) or neophyl (PhC(Me)2CH2) substituents in the central ring were unsuccessful. All the compounds were fully characterized by elemental analysis, melting point, IR and NMR spectroscopy. The structure of compound 6 was corroborated by single‐crystal X‐ray diffraction measurements.