Poly-Lewis-acids based on bowl-shaped tribenzotriquinacene

Abstract

Several derivatives of bowl-shaped tribenzotriquinacenes with Lewis-acidic atoms are reported. Six acetylene functions were attached to the benzene rings and these can carry six SnMe₃ or SiMe₃ groups. Direct functionalization of the benzhydrylic positions with the silyl groups of tribenzotriquinacene in in situ Grignard reactions is reported. Such silyl groups carry various substituents; the Si–H functional species were shown to be convertible into Si–F, Si–Cl and Si–Br functional compounds. The benzhydrylic positions were also substituted by allyl and p-iodo-phenyl functions; the first were further functionalized with a variety of silyl groups (SiCl₃, SiMeCl₂, SiF₃, SiMeF₂), the latter with trimethylsilylethynyl substituents and this product desilylated to a tris-(p-ethynyl-phenyl) tribenzotriquinacene. The complexation of a SbCl₃ unit by a tribenzotriquinacene derivative with a new chelating tris-arene binding motif of the antimony atom is also reported.