Experimental and theoretical studies on gold(iii) carbonyl complexes: reductive C,H- and C,C bond formation
Experimental and theoretical studies on gold(iii) carbonyl complexes: reductive C,H- and C,C bond formation
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DOI：
10.1039/d1dt01315g
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发表时间：
2021-05-12
影响因子：
4
通讯作者：
Hashmi, A. Stephen K.
中科院分区：
文献类型：
--
作者：
Ahrens, Alexander;Lustosa, Danilo M.;Hashmi, A. Stephen K.
研究了阳离子型金（III）羰基配合物的反应活性。虽然原位形成的IPrAu（bph）CO+络合物（bph =联苯-2，2 '-二基）不经历CO迁移插入到相邻的金-碳键中，但亲核试剂可以在分子间攻击配位的CO部分。水作为亲核试剂引发CO2挤出并形成还原性C，H键。从中间体羰基金（iii）快速形成金（i）物质之前尚未观察到，并且显示出（CC）和（CNC）羰基金（iii）之间的反应性的显著差异。据报道，后者通过WGS反应形成稳定的金（iii）氧化物。在甲醇作为亲核试剂攻击金（iii）羰基的情况下，没有观察到挤出的CO2。相反，中间体金（iii）羧基络合物通过还原性C-C键消除形成芳基羧酸酯。该机制的实验和理论研究解释了所观察到的选择性，并给出了新的见解难以捉摸的金（三）羰基的反应性。
The reactivity of cationic (CC)gold(iii) carbonyl complexes was investigated. While the in situ-formed IPrAu(bph)CO+ complex (bph = biphenyl-2,2 '-diyl) does not undergo a migratory insertion of CO into the neighboring gold-carbon bond, nucleophiles can attack the coordinated CO moiety intermolecularly. Water as a nucleophile initiates a CO2 extrusion combined with a reductive C,H bond formation. The rapid formation of a gold(i) species from an intermediary gold(iii) carbonyl has not been observed before and shows a significant difference in reactivity between (CC) and (CNC)gold(iii) carbonyls. The latter have been reported to form stable gold(iii) hydrides via the WGS reaction. In the case of methanol acting as a nucleophile attacking the gold(iii) carbonyl, no extrusion of CO2 is observed. Instead an intermediary gold(iii) carboxyl complex forms an aryl carboxylate via reductive C-C bond elimination. Experimental and theoretical studies on the mechanism explain the observed selectivities and give new insights into the reactivity of elusive gold(iii) carbonyls.