915299-24-0Relevant articles and documents
Taming gold(I)-counterion interplay in the de-aromatization of indoles with allenamides
Jia, Minqiang,Cera, Gianpiero,Perrotta, Daniele,Monari, Magda,Bandini, Marco
, p. 9875 - 9878 (2014)
A careful interplay between the π electrophilicity of a cationic Au I center and the basicity of the corresponding counterion allowed for the chemo- and regioselective inter- as well as intramolecular de-aromatization of 2,3-disubstituted indoles with allenamides. The silver-free bifunctional Lewis acid/Bronsted base complex [{2,4-(tBu)2C 6H3O}3PAuTFA] assisted the formation of a range of densely functionalized indolenines under mild conditions.
Gold(I)-Catalyzed and Nucleophile-Guided Ligand-Directed Divergent Synthesis
Lee, Yen-Chun,Knauer, Lena,Louven, Kathrin,Golz, Christopher,Strohmann, Carsten,Waldmann, Herbert,Kumar, Kamal
supporting information, p. 5688 - 5699 (2018/10/31)
Transition metal catalysts can mediate a plethora of skeleton rearrangements of a range of substrates to construct complex small molecules. Yet, their potential to transform common substrates into distinct molecular scaffolds has not been fully explored to deliver biologically relevant small molecules. Gold(I)-catalyzed transformations of enynes are amongst the most intriguing rearrangements and provide opportunities to access a range of diverse scaffolds efficiently. In ligand-directed divergent synthesis (LDS), variation of ligands in metal complexes determines the fate of substrates during their transformation into distinct scaffolds. For instance, variation of ligands for the gold(I) catalysts helps to transform oxindole derived 1,6-enynes into several distinct molecular frameworks. In this report, we present how ligand variation in gold(I) catalysts, nucleophile-additives and alkyl and alkynyl substitutions on the 1,6-enynes as well as replacement of the oxindole ring with a different privileged ring-system (PRS) influence the LDS approach to access a wider chemical space. Based on the experimental results, we propose several mechanistic pathways in gold(I)-catalyzed cycloisomerizations and cascade reactions of 1,6-enyne substrates leading to structurally distinct chemotypes.
Efficient general procedure to access a diversity of gold(0) particles and gold(I) phosphine complexes from a simple HAuCl4 source. Localization of homogeneous/heterogeneous system's interface and field-emission scanning electron microscopy study
Zalesskiy, Sergey S.,Sedykh, Alexander E.,Kashin, Alexey S.,Ananikov, Valentine P.
supporting information, p. 3550 - 3559 (2013/05/09)
Soluble gold precatalysts, aimed for homogeneous catalysis, under certain conditions may form nanoparticles, which dramatically change the mechanism and initiate different chemistry. The present study addresses the question of designing gold catalysts, taking into account possible interconversions and contamination at the homogeneous/heterogeneous system's interface. It was revealed that accurate localization of boundary experimental conditions for formation of molecular gold complexes in solution versus nucleation and growth of gold particles opens new opportunities for well-known gold chemistry. Within the developed concept, a series of practical procedures was created for efficient synthesis of soluble gold complexes with various phosphine ligands (R3P)AuCl (90-99% yield) and for preparation of different types of gold materials. The effect of the ligand on the particles growth in solution has been observed and characterized with high-resolution field-emission scanning electron microscopy (FE-SEM) study. Two unique types of nanostructured gold materials were prepared: hierarchical agglomerates and gold mirror composed of ultrafine smoothly shaped particles.
