Influence of a Very Bulky <i>N-</i>Heterocyclic Carbene in Gold-Mediated Catalysis
作者:Adrián Gómez-Suárez、Rubén S. Ramón、Olivier Songis、Alexandra M. Z. Slawin、Catherine S. J. Cazin、Steven P. Nolan
DOI:10.1021/om200705y
日期:2011.10.24
related gold complexes [Au(IPr*)Cl] (C1) and [Au(IPr*)(NTf2)] (C2) were achieved in high yields. The % VBur of IPr* for both gold complexes was measured, revealing IPr* as one of the bulkiest NHCs on gold complexes reported to date. In addition, the catalytic activity of C1 and C2 in several reactions, typically catalyzed by AuI complexes, was investigated. Examples include the tandem alkoxylation/lactonization
游离卡宾IPr *(IPr * = 1,3-双(2,6-双(二苯基甲基)-4-甲基苯基)咪唑-2-亚烷基)和相关金配合物[Au(IPr *)Cl]的合成(高产率地获得了C1)和[Au(IPr *)(NTf 2)](C2)。测量了两种金络合物的IPr *的V Bur%,表明IPr *是迄今为止报道的金络合物中最大的NHC之一。此外,C1和C2在几个反应中的催化活性(通常由Au I催化)配合物,进行了调查。实例包括γ-羟基-α,β-炔属酸酯的串联烷氧基化/内酯化,乙酸炔丙酯的[3,3]重排导致共轭烯酮和取代的茚的形成以及乙酸烯丙酯的重排。这些研究表明,以1,2-二氯乙烷为选择溶剂对溶剂的催化活性有很强的影响。与带有大分子配体(例如IPr和SIPr)的[Au(NHC)(L)]配合物相比,C1和C2的筛选仅显示出稍微减弱的活性。