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A New Type of Chiral Sulfinamide Monophosphine Ligands: Stereodivergent Synthesis and Application in Enantioselective Gold(I)‐Catalyzed Cycloaddition Reactions
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Zhan‐Ming Zhang Peng Chen Dr. Wenbo Li Yanfei Niu Prof. Dr. Xiao‐Li Zhao Prof. Dr. Junliang Zhang 《Angewandte Chemie (International ed. in English)》2014,53(17):4350-4354
A simple, new type of chiral sulfinamide monophosphines, the so‐called Ming‐Phos ligands, is reported; these ligands could be easily prepared from inexpensive and commercially available starting materials. The Ming‐Phos ligands performed well in the enantioselective gold‐catalyzed cycloaddition reaction of 2‐(1‐alkynyl)‐alk‐2‐en‐1‐ones with nitrones. Both enantiomers of the products could be obtained in good yields and with excellent diastereo‐ and enantioselectivity through transformations that were catalyzed by gold complexes derived from two diastereomers of Ming‐Phos ligand M5 (Ar=1‐naphthyl). 相似文献
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Prof. Louise A. Berben 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(7):2734-2742
Non‐Innocent ligand complexes of aluminum are described in this Concept article, beginning with a discussion of their synthesis, and then structural and electronic characterization. The main focus concerns the ability of the ligands in these complexes to mediate proton transfer reactions. As examples, aluminum–ligand cooperation in the activation of polar bonds is described, as is the importance of hydrogen bonding to stabilization of a transition state for β‐hydride abstraction. Taken together these reactions enable catalytic processes such as the dehydrogenation of formic acid. 相似文献
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Alejandro Cervantes-Reyes Dr. Frank Rominger Dr. Matthias Rudolph Prof. Dr. A. Stephen K. Hashmi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(50):11745-11757
Nine- and ten-membered N-heterocyclic carbene (NHC) ligands have been developed and for the first time their gold(I) complexes were synthesized. The protonated NHC pro-ligands 2 a – h were prepared by the reaction of readily available N,N′-diarylformamidines with bis-electrophilic building blocks, followed by anion exchange. In situ deprotonation of the tetrafluoroborates 2 a – h with tBuOK in the presence of AuCl(SMe2) provided fast access to NHC-gold(I) complexes 3 – 10 . These new NHC-gold(I) complexes show very good catalytic activity in a cycloisomerization reaction (0.1 mol % catalyst loading, up to 100 % conversion) and their solid-state structures reveal high steric hindrance around the metal atom (%Vbur up to 53.0) which is caused by their expanded-ring architecture. 相似文献
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Valentina Stoppa Edoardo Battistel Marco Baron Paolo Sgarbossa Andrea Biffis Gregorio Bottaro Lidia Armelao Cristina Tubaro 《Molecules (Basel, Switzerland)》2022,27(13)
The use of alkynyl gold(I) complexes covers different research fields, such as bioinorganic chemistry, catalysis, and material science, considering the luminescent properties of the complexes. Regarding this last application, we report here the synthesis of three novel dinuclear gold(I) complexes of the general formula [(diNHC)(Au-C≡CPh)2]: two Au-C≡CPh units are connected by a bridging di(N-heterocyclic carbene) ligand, which should favor the establishment of semi-supported aurophilic interactions. The complexes can be easily synthesized through mechanochemistry upon reacting the pristine dibromido complexes [(diNHC)(AuBr)2] with phenylacetylene and KOH. Interestingly, we were also able to isolate the monosubstituted complex [(diNHC)(Au-C≡CPh)(AuBr)]. The gold(I) species were fully characterized by multinuclear NMR spectroscopy and mass spectrometry. The emission properties were also evaluated, and the salient data are comparable to those of analogous compounds reported in the literature. 相似文献
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Dr. T. Srinivasa Reddy Dr. Deep Pooja Dr. Steven H. Privér Dr. Rodney B. Luwor Dr. Nedaossadat Mirzadeh Dr. Shwathy Ramesan Dr. Sistla Ramakrishna Shailaja Karri Dr. Madhusudana Kuncha Prof. Suresh K. Bhargava 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(62):14089-14100
Four cycloaurated phosphine sulfide complexes, [Au{κ2-2-C6H4P(S)Ph2}2][AuX2] [X=Cl ( 2 ), Br ( 3 ), I ( 4 )] and [Au{κ2-2-C6H4P(S)Ph2}2]PF6 ( 5 ), have been prepared and thoroughly characterized. The compounds were found to be stable under physiological-like conditions and showed excellent cytotoxicity against a broad range of cancer cell lines and remarkable cytotoxicity in 3D tumor spheroids. Mechanistic studies with cervical cancer (HeLa) cells indicated that the cytotoxic effects of the compounds involve the inhibition of thioredoxin reductase and induction of apoptosis through mitochondrial disruption. In vivo experiments in nude mice bearing HeLa xenografts showed that treatment with compounds 4 and 5 resulted in significant inhibition of tumor growth (35.8 and 46.9 %, respectively), better than that of cisplatin (29 %). The newly synthesized gold complexes were also evaluated for their in vitro and in vivo anti-inflammatory activity through the study of lipopolysaccharide (LPS)-activated macrophages and carrageenan-induced hind paw edema in rats, respectively. 相似文献
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Alejandro Portugués Dr. Delia Bautista Dr. Juan Gil-Rubio 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(63):15815-15822
New dinuclear Au(I), Au(II) and Au(III) complexes containing (CF2)n bridging chains were obtained. Metallomacrocycles [Au2{μ-(CF2)4}{μ-diphosphine}] show an uncommon figure-eight structure, the helicity inversion barrier of which is influenced by aurophilic interactions and steric constraints imposed by the diphosphine. Halogenation of LAu(CF2)4AuL (L=PPh3, PMe3, (dppf)1/2, (binap)1/2) gave [Au(II)]2 species, some of which display unprecedented folded structures with Au−Au bonds. Aurophilic interactions facilitate this oxidation process by preorganizing the starting [Au(I)]2 complexes and lowering its redox potential. The obtained [Au(II)]2 complexes undergo thermal or photochemical elimination of R3PAuX to give Au(III) perfluorinated auracycles. Evidence of a radical mechanism for these decomposition reactions was obtained. 相似文献
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Dr. Mathilde Rigoulet Dr. Karinne Miqueu Dr. Didier Bourissou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(60):e202202110
The mechanism of oxy-arylation/vinylation of alkenes catalyzed by the (MeDalphos)AuCl complex was comprehensively investigated by DFT. (P,N)Au(Ph)2+ and (P,N)Au(vinyl)2+ are key intermediates accounting for the activation of the alkenols and for their cyclization by outer-sphere nucleophilic attack of oxygen. The 5-exo and 6-endo paths have been computed and compared, reproducing the peculiar regioselectivity difference observed experimentally between 4-penten-1-ol, (E) and (Z)-4-hexen-1-ols. Examining the way the alkenol coordinates to gold (more η2 or η1) can offer, in some cases, a simple way to predict the favored path of cyclization. 相似文献
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Koshevoy IO Lin CL Karttunen AJ Jänis J Haukka M Tunik SP Chou PT Pakkanen TA 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(41):11456-11466
Reactions of the homoleptic (AuC(2)R)(n) precursors with stoichiometric amount of diphosphine ligand PPh(2)C(6)H(4)PPh(2) (P^P) and Cu(+) ions lead to an assembly of a new family of bimetallic clusters [Au(6)Cu(2)(C(2)R)(6)(P^P)(2)](2+) (type I; R=9-fluorenolyl (1), diphenylmethanolyl (2), 2,6-dimethyl-4-heptanolyl (3), 1-cyclohexanolyl (4), Cy (5), tBu (6)). In the case of R=1-cyclohexanolyl, a structurally different complex [Au(6)Cu(2)(C(2)C(6)H(11)O)(6)(P^P)(3)](2+) (7, type II) could be obtained by treatment of 4 with one equivalent of the diphosphine, while for R=isopropanolyl only the latter type of cluster [Au(6)Cu(2)(C(2)C(3)H(7)O)(6)(P^P)(3)](2+) (8) was detected. Steric bulkiness of the alkynyl ligands and O···H-O hydrogen bonding are suggested to play an important role in stabilizing the type I and type II cluster structural motif, respectively. All the complexes exhibit intense photoluminescence in solution with emission parameters that depending on the geometrical arrangement of the octanuclear metal core. The clusters 1-4 and 6 show single emission band in a blue region (469-488 nm) with maximum quantum yield of 94% (4), while structurally different 7 and 8 emit yellow-orange (590 nm) with unity quantum efficiency. The theoretical DFT calculations of the electronic structures have been carried out to demonstrate that the metal-centered triplet emission within the heterometallic core plays a key role for the observed phosphorescence. 相似文献
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The centrosymmetric {[(HOOCCH2PPh2)]2(CH2)4}2+ cation adopts an extended conformation in which the phosphorus center adopts a tetrahedral geometry. O? H···O and C? H···O hydrogen bonding interactions expand this structure to form a two‐dimensional layered architecture. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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Cover Picture: Ylide‐Functionalized Phosphines: Strong Donor Ligands for Homogeneous Catalysis (Angew. Chem. Int. Ed. 39/2018)
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Thorsten Scherpf Christopher Schwarz Lennart T. Scharf Jana‐Alina Zur Andreas Helbig Prof. Dr. Viktoria H. Gessner 《Angewandte Chemie (International ed. in English)》2018,57(39):12587-12587
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Andriani Furoida Misato Daitani Kyohei Hisano Osamu Tsutsumi 《Molecules (Basel, Switzerland)》2021,26(23)
Gold(I) complexes, enabling to form linear coordination geometry, are promising materials for manifesting both aggregation-induced emission (AIE) behavior due to strong intermolecular Au–Au (aurophilic) interactions and liquid crystalline (LC) nature depending on molecular geometry. In this study, we synthesized several gold(I) complexes with rod-like molecular skeletons where we employed a mesogenic biphenylethynyl ligand and an isocyanide ligand with flexible alkoxyl or alkyl chains. The AIE behavior and LC nature were investigated experimentally and computationally. All synthesized gold(I) complexes exhibited AIE properties and, in crystal, room-temperature phosphorescence (RTP) with a relatively high quantum yields of greater than 23% even in air. We have demonstrated that such strong RTP are drastically changed depending on the crystal-size and/or crystal growth process that changes quality of crystals as well as the aggregate structure, of e.g., Au–Au distance. Moreover, the complex with longer flexible chains showed LC nature where RTP can be observed. We expect these rod-like gold(I) complexes to have great potential in AIE-active LC phosphorescent applications such as linearly/circularly polarizing phosphorescence materials. 相似文献
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Prof. Gianpiero Cera Gabriele Giovanardi Prof. Andrea Secchi Prof. Arturo Arduini 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(40):10261-10266
We report the synthesis and characterization of novel triphosphine calix[6]arene ligands. These supramolecular wheels, with recognition features governed by the hydrogen-bonding domain, were employed to synthesize multitasking trinuclear gold(I) complexes as a new platform for the synthesis of interwoven (pseudo)rotaxane species. In parallel, the multivalent, metal-bonded upper rim displayed catalytic features promoting highly selective gold-catalyzed cycloisomerization reactions of 1,6-enynes. 相似文献