Tris(trimethylsilyl)methyltin oxinates and their conversion into bis-(trimethylsilyl)methyltin oxinates
Abstract
8-Hydroxyquinoline reacts in ethanol with organotin halides SnRX3, SnR′RX2, SnR′2RX [where R′= Me or Ph; R =(Me3Si)3C; X = halide] to yield oxinate complexes [SnR(ox)3], [Sn(OEt)R(ox)2], [SnR′R(ox)2], and [SnR′2R(ox)]. The [SnR′R(ox)2] complexes exist in two cis isomeric forms. When the di- or tri-oxinates are heated in ethanol nucleophilic cleavage of one trimethylsilyl group occurs yielding the bis(trimethylsilyl)methyl compounds, [Sn(OEt){CH(SiMe3)2}(ox)2] and [SnR′{CH(SiMe3)2}(ox)2]. The methyl complex has the structure cis-[SnMe{CH(SiMe3)2}(ox)2] with nitrogen trans to both Sn–C bonds. Hydrobromic acid readily converts these oxinates into the corresponding bromides.