Oxidative Bond Formation and Reductive Bond Cleavage at Main Group Metal Centers: Reactivity of Five-Valence-Electron MX2 Radicals

Monomeric five-valence-electron bis­(boryl)
complexes of gallium,
indium, and thallium undergo oxidative M–C bond formation with
2,3-dimethylbutadiene, in a manner consistent with both the redox
properties expected for MII species and with metal-centered
radical character. The weaker nature of the M–C bond for the
heavier two elements leads to the observation of reversibility in
M–C bond formation (for indium) and to the isolation of products
resulting from subsequent B–C reductive elimination (for both
indium and thallium).

单原子五价电子硼基复合物，包括镓、铟和铊，与2,3-二甲基丁二烯发生氧化M-C键形成反应，其过程既符合MII物种所预期的氧化还原性质，也符合金属中心自由基的特征。对于较重的两种元素，M-C键的较弱性质导致M-C键形成过程的可逆性（对于铟）以及后续B-C还原消除产物的分离（对于铟和铊）得以观测。