The redox chemistry of mononuclear and dinuclear gold(I) phosphine arylthiolate complexes was recently investigated by using electrochemical, chemical, and photochemical techniques. We now report the redox chemistry of dinuclear gold(I) phosphine complexes containing aliphatic dithiolate ligands. These molecules differ from previously studied gold(I) phosphine thiolate complexes in that they are cyclic and contain aliphatic thiolates. Cyclic voltammetry experiments of Au(2) (LL)(pdt) [pdt = propanedithiol; LL = 1,2-bis(diphenylphosphino)-ethane (dppe), 1,3-bis(diphenylphosphino)propane (dppp), 1,4-bis(diphenylphosphino)butane (dppb), 1,5-bis(diphenylphosphino)pentane (dpppn)] in 0.1 M TBAH/CH(3)CN or CH(2)Cl(2) solutions at 50 to 500 mV/sec using glassy carbon or platinum electrodes, show two irreversible anodic processes at ca. +0.6 and +1.1 V (vs. SCE). Bulk electrolyses at +0.9 V and +1.4 V result in n values of 0.95 and 3.7, respectively. Chemical oxidation of Au(2)(dppp)(pdt) using one equivalent of Br(2) (2 oxidizing equivalents) yields 1,2-dithiolane and Au(2)(dppp)Br(2). The reactivity seen upon mild oxidation = +1.0 V is consistent with formal oxidation of a thiolate ligand, followed by a fast chemical reaction that results in cleavage of a second gold-sulfur bond. Oxidation at higher potentials (>/= +1.3 V) is consistent with oxidation of gold(I) to gold(III). Structural and electrochemical differences between gold(I) aromatic and aliphatic thiolate oxidation processes are discussed.
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http://dx.doi.org/10.1155/MBD.1994.419 | DOI Listing |
Tetrahedron Lett
October 2024
Department of Chemistry, University of California, Berkeley, CA 94720, USA.
Neutral dual hydrogen bond donors (HBDs) are effective catalysts that enhance the electrophilicity of substrates or the Lewis/Brønsted acidity of reagents through an anion-binding mechanism. Despite their success in various enantioselective organocatalytic reactions, their application to transition metal catalysis remains rare. Herein, we report the activation of gold(I) precatalysts by chiral ureas, leading to enantioselective hydroarylation of allenes with indoles.
View Article and Find Full Text PDFEur J Med Chem
January 2025
School of Science, STEM College, RMIT University, Melbourne, Victoria, 3001, Australia. Electronic address:
Four new mononuclear gold (I) compounds of the type [AuL{κC-2-CHP(S)Ph}] {L = PTA (1), PPh (2), PPh(CH-3-SONa) (3), and PPh(2-py) (4)} were prepared by scission of the dinuclear compound [Au{μ-2-CHP(S)Ph}] by L or via a transmetalation reaction using the organotin reagent 2-MeSnCHP(S)Ph and a suitable gold halide precursor. The cytotoxic potential of complexes 1-4 was evaluated against four human cancer cell lines of diverse cellular origin: cervical (HeLa), prostate (PC-3), non-small cell lung adenocarcinoma (A549), and fibrosarcoma (HT-1080). The in vitro cytotoxicity results showed that 1 demonstrated exceptional anticancer activity with IC values ranging from 0.
View Article and Find Full Text PDFActa Biochim Biophys Sin (Shanghai)
September 2024
Fujian Provincial Key Laboratory of Translational Cancer Medicine, Clinical Oncology School of Fujian Medical University, Fujian Cancer Hospital, Fuzhou 350014, China.
Hepatocellular carcinoma (HCC), the predominant type of liver cancer, is an aggressive malignancy with limited therapeutic options. In this study, we assess a collection of newly designed gold(I) phosphine complexes. Remarkably, the compound GC002 exhibits the greatest toxicity to HCC cells and outperforms established medications, such as sorafenib and auranofin, in terms of antitumor efficacy.
View Article and Find Full Text PDFJ Am Chem Soc
October 2024
State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
A diarylurea-containing phosphine ligand-modulated stereoinvertive -glycosylation with primal furanosyl and pyranosyl -alkynylbenzoate () donors under gold(I) catalysis is disclosed. Both α- and β-configured glycosides could be obtained from the corresponding stereochemically pure β- and α-glycosyl donors with high yields and good to excellent stereoselectivities, respectively. This method accommodates a variety of glycosyl donors and alcoholic acceptors, leading to both 1,2- and 1,2- glycosidic linkages, and has been applied to the convenient preparation of a series of linear arabinan glycans.
View Article and Find Full Text PDFInorg Chem
September 2024
Chemical Sciences and Technology Division, CSIR- National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram, Kerala 695019, India.
Gold catalysis enables selective chemical transformations with catalytic activity tunable through ligand selection. This study uses the density functional theory (DFT) to explore the impact of phosphine ligands (PR) on gold(I)-catalyzed alkyne-alkene cyclobutene formation. We analyze the following key steps: (i) PR-Au complexation, (ii) alkyne binding, (iii) alkene binding, (iv) C-C coupling transition state, (v) cyclobutene formation transition state, and (vi) cyclobutene dissociation.
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