WestCHEM, Department of Pure & Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
Chemistry. 2013 Feb 11;19(7):2487-95. doi: 10.1002/chem.201202314. Epub 2013 Jan 7.
The alkylation reactions of soft scorpionates are reported. The hydrotris(S-alkyl-methimazolyl)borate dications (alkyl = methyl, allyl, benzyl), which were prepared by the reaction of Tm(Me) anion and primary alkyl halides, have been isolated and structurally characterised. The reaction is, however, not universally successful. DFT analysis of these alkylation reactions (C=S versus B-H alkylation) indicates that the observed outcome is driven by kinetic factors. Extending the study to incorporate alternative imine thiones (mercaptobenzothiazole, bz; thiazoline, tz) led to the structural characterisation of di[aquo-μ-aquohydrotris(mercaptobenzothiazolyl)boratosodium], which contains sodium atoms in the κ(3)-S,S,S coordination mode. Alkylation of Na[Tbz] and Na[tzTtz] leads to decomposition resulting in the formation of the simple S-alkylated heterocycles. The analysis of the species involved in these reactions shows an inherent weakness in the B-N bond in soft scorpionates, which has implications for their use in more advanced chemistry.
报道了软硫堇配体的烷基化反应。通过 Tm(Me) 阴离子与伯卤代烷反应制备了氢三（S-烷基-甲巯咪唑基）硼酸二阳离子（烷基=甲基、烯丙基、苄基），并对其进行了分离和结构表征。然而，该反应并非普遍成功。这些烷基化反应（C=S 与 B-H 烷基化）的 DFT 分析表明，观察到的结果是由动力学因素驱动的。将研究扩展到包含替代亚胺硫酮（巯基苯并噻唑、bz；噻唑啉、tz），导致了二[水合-μ-羟三水（巯基苯并噻唑基）硼酸根合]钠的结构表征，其中含有κ(3)-S、S、S 配位模式的钠离子。Na[Tbz]和 Na[tzTtz]的烷基化导致分解，形成简单的 S-烷基化杂环。对这些反应中涉及的物种的分析表明，软硫堇配体中的 B-N 键存在固有弱点，这对它们在更先进的化学中的应用有影响。
