- Synthesis and solution- and solid-state characterization of gold(I) rings with short Au...Au interactions. Spontaneous resolution of a gold(I) complex
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We report the synthesis and solution- and solid-state characterization of gold(I) rings with short 1,9-transannular Au...Au interactions. The 9- and 16-membered gold(I) rings were prepared by reacting 9,9-dimethyl-4,5-bis(diphenylphosphino)-xanthene and (Me2S)AuCl in the presence of AgNO3 in the molar ratio of 1:0.5:1 and 1:1:1, respectively. X-ray crystallographic measurements in conjunction with solution X-ray diffraction and NMR methods have been used to determine the structure of gold(I) rings, and we also gained insight into the dynamics. The nine-membered gold(I) ring is chiral, and the crystal contains only one of the two enantiomers, either right- or left-handed. To the best of our knowledge this represents the first example of crystallization-induced spontaneous resolution of a binuclear gold(I) cycle. The 16-membered ring with 1,9-transannular Au...Au interaction is in a figure-eight conformation. Copyright
- Deak, Andrea,Megyes, Tuende,Tarkanyi, Gabor,Kiraly, Peter,Biczok, Laszlo,Palinkas, Gabor,Stang, Peter J.
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- Unexpected formation of a fused double cycle trinuclear gold(i) complex supported by: Ortho -phenyl metallated aryl-diphosphine ligands and strong aurophilic interactions
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The first homoleptic trinuclear arylgold(i) complex, [Au3(L′)2](NO3) (3), based on an ortho-phenyl metallated aryl-diphosphine ligand (L′ = o-C6H4PPh(C15H10O)PPh2), has been obtained through a new thermolytic reaction of the corresponding diauracycle, [Au2(L)2](NO3)2 (L = xantphos). The formation of 3 involves activation of the ortho-phenyl C-H bond of the xantphos ligands. The presence of Au-C bonds in this new gold-diphosphine cluster is not its only remarkable feature, since it also displays two 12-membered rings fused together and a linear {Au3} chain with aurophilic interactions. Complex 3 exhibits strong sky-blue luminescence that can be assigned to a triplet metal-metal (3MM) transition partially mixed with a ligand-to-metal-metal charge transfer (3LMMCT) transition related to the aurophilic bonding. This [Au3(L′)2]+ triauracycle also shows AIEE-activity, and is a selective luminescent chemosensor for metal ions.
- Jobbágy, Csaba,Baranyai, Péter,Szabó, Pál,Holczbauer, Tamás,Rácz, Barbara,Li, Liang,Naumov, Pan?e,Deák, Andrea
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- Gold-Catalyzed Oxidative Coupling of Alkynes toward the Synthesis of Cyclic Conjugated Diynes
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Gold-catalyzed oxidative coupling of alkynes was developed as an efficient approach for the synthesis of challenging cyclic conjugated diynes (CCD). Compared with the classic copper-promoted oxidative coupling reaction of alkynes, this gold-catalyzed process exhibited a faster reaction rate due to rapid reductive elimination from the Au(III) intermediate. This unique reactivity thus allowed a challenging diyne macrocyclization to take place with high efficiency. Condition screening revealed an [(n-Bu)4N]+[Cl-Au-Cl]? salt as the optimal pre-catalyst. Macrocycles with ring size between 13 and 28 atoms were prepared in moderate to good yields, which highlighted the broad substrate scope of this new strategy. Furthermore, the synthetic utilities of the CCDs for copper-free click chemistry have been demonstrated, showcasing the potential application of this strategy in biological systems. Macrocycles are important structural moieties in medicinal and biological research, and efficient methods for macrocyclization are always in high demand. With the unique conformation having six carbon atoms in a linear geometry, the cyclic conjugated diynes (CCD) present greater synthetic challenges and have been much less explored. Therefore, application of these unique macrocycles in biological studies is largely unexplored. Here, we describe the discovery of gold-catalyzed Glaser-Hay type oxidative coupling of terminal alkynes to achieve CCD under diluted conditions with broad substrate scope and great functional group compatibility. Taking advantage of the 14-member cyclic diyne, a copper-free click chemistry was achieved, which provided an effective alternative strategy for the traditional cyclooctyne-based azide-alkyne cycloaddition, suggesting a promising future for this method in tackling challenging problems in related biological and medicinal research. Gold-catalyzed oxidative coupling of alkynes was developed as an efficient approach for the synthesis of challenging cyclic conjugated diyne. Compared with copper-promoted oxidative coupling, this protocol allowed macrocyclization under dilute conditions with good overall reactivity and high functional group tolerance. The success in achieving copper-free click chemistry on cyclic conjugated diyne highlights its potential application in biological and medicinal research.
- Ye, Xiaohan,Peng, Haihui,Wei, Chiyu,Yuan, Teng,Wojtas, Lukasz,Shi, Xiaodong
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supporting information
p. 1983 - 1993
(2018/10/02)
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- Synthesis and optical properties of binuclear gold(I) complexes with bridging phosphine ligands: Luminescence from intraligand and metal-centered excited states
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The complexes Au2Cl2(P-P) with P-P = biphep (2,2′-bis(diphenylphosphino)-1,1′-biphenyl), binap (2,2′-bis(diphenylphosphino)-1,1′-binaphthyl) and xantphos (9,9′-dimethyl-4,5-bis(diphenyl-phosphino)xanthene), were prepared and characterized by elemental analysis and ESI-MS. The solid compounds show a r.t. phosphorescence. While the binap complex emits from an intraligand (IL) triplet, the luminescence of the biphep complex originates from a metal-centered (MC) triplet which is presumably lowered by gold-gold interaction. The xantphos complex displays a dual phosphorescence. In this case, the emitting triplets are of the IL and MC type.
- Pawlowski, Valeri,Kunkely, Horst,Vogler, Arnd
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p. 1309 - 1312
(2008/10/09)
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