A di(o-tolyl)borylgold complex was synthesized via the metathesis reaction of a gold alkoxide with tetra(o-tolyl)diborane(4). The resulting diarylborylgold complex exhibited a Lewis acidic boron center and a characteristic visible absorption that arises from its HOMO–LUMO excitation, which is narrower than that of a previously reported dioxyborylgold complex. The diarylborylgold complex reacted with isocyanide in a stepwise fashion to afford single- and double-insertion products and a C–C coupled product. Reactions of this diarylborylgold complex with CO/N double bond species furnished addition products under concomitant formation of Au–C and B–O/N bonds, which suggests nucleophilic reactivity of the gold metal center. DFT calculations provided details of the underlying reaction mechanism, which involves an initial coordination of the CO/N bond to the boron vacant p-orbital of the diarylboryl ligand followed by a migration of the gold atom from the tetracoordinate sp³-hybridized boron center, which is analogous to the reactivity of the conventional sp³-hybridized borate species. The DFT calculations also suggested a stepwise mechanism for the reaction of this diarylborylgold complex with isocyanide, which afforded three different reaction products depending on the applied reaction conditions.

中文翻译：

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二芳基硼基金（I）络合物中金原子对极性多重键的亲核反应性

通过烷醇金与四（邻甲苯基）二硼烷（4）的复分解反应合成了二（邻甲苯基）硼基金配合物。生成的二芳基硼金复合物表现出路易斯酸性硼中心，并且由于其HOMO-LUMO激发而具有特征性的可见吸收，该吸收比以前报道的二氧硼基金复合物窄。二芳基硼基金配合物与异氰酸酯逐步反应，得到单插入和双插入产物以及C-C偶联产物。该二芳基硼基金配合物与C的反应O / N双键物种在Au-C和B-O / N键的同时形成下提供了加成产物，这表明金金属中心具有亲核活性。DFT计算提供了潜在反应机理的详细信息，该反应机理涉及与二芳基硼基配体的硼空位p轨道的C O / N键初始配位，然后从四配位sp ^3-杂化硼中心迁移金原子。类似于传统的sp ^3-杂交的硼酸盐种类的反应性。DFT计算还提出了该二芳基硼烷基金配合物与异氰化物反应的分步机理，根据所应用的反应条件，该反应可提供三种不同的反应产物。