The conventional synthetic approach to transition metal pincer complexes calls for the preparation of the tridentate pincer (proto)ligand first, with subsequent introduction of the transition metal center as the last step. This work demonstrates that the alternative synthetic logic, where the central main group element is introduced last, can be applicable to a number of PEP pincer complexes (E = B, Al, Si, P) derived from phosphinophenols and phosphinopyrroles. This approach obviates the need to isolate well-behaved proto-pincer precursors, and instead relies on the formation of phosphine-metal adducts first, whose nature determines the stoichiometry of the needed main group reagent to complete the synthesis.

中文翻译：

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过渡金属作为模板：在钳形复合物的制备中反转合成逻辑


过渡金属钳络合物的常规合成方法要求首先制备三齿钳形（原始）配体，最后一步引入过渡金属中心。这项工作表明，最后引入中心主族元素的替代合成逻辑可以适用于衍生于膦酚和膦吡咯的许多 PEP 钳形复合物 （E = B， Al， Si， P）。这种方法消除了分离行为良好的原钳前体的需要，而是首先依赖于膦金属加合物的形成，其性质决定了完成合成所需的主基团试剂的化学计量。