Gold(III) Meets Azulene: A Class of [(tBuC∧N∧C)AuIII(azulenyl)] Pincer Complexes

Eppel, Daniel; Oberhof, Nils; Dietl, Martin C.; Cieslik, Patrick; Rudolph, Matthias; Eberle, Lukas; Krämer, Petra; Stuck, Fabian; Röminger, Frank; Dreuw, Andreas; Hashmi, A. Stephen K.

doi:10.1021/acs.organomet.1c00535

Cited by 7 publications

(2 citation statements)

References 61 publications

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“…Of note, internal monoaryl alkynes are inert towards the cationic gold catalyst. Later, the same group developed a synthetic route to a class of [( t Bu C N C)Au(III)(azulenyl)] pincer complexes using the azulenes obtained by this elegant gold‐catalyzed dimerization of diarylalkynes [24b] …”

Section: Azulenes From Transition Metal‐catalyzed Formal Crossed [2+2...mentioning

confidence: 99%

Direct Access to Functionalized Azulenes and Pseudoazulenes via Unconventional Alkyne Cyclization Reactions

Wang

2023

Chemistry An Asian Journal

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Owing to the unique chemical structure and photophysical properties of azulene, azulene derivatives show great promise for a wide range of prospective technical applications, such as molecular switching, sensors, solar cells, and biological activities. In addition to functionalization of the existed azulene cores, direct construction of azulenes via condensation with odd‐membered carbocycles such as tropolone, 2‐oxazulanone, cyclopentadiene, and 6‐aminofulvene is another classical method for obtaining azulene derivatives. Although alkynes are widely explored for construction of benzene rings, several unconventional cyclization reactions with alkynes produce azulene, pseudoazulene, or azulenone skeletons. This minireview summarizes these interesting and practical cyclization with a classification based on the function of alkyne in the azulene formation process, aiming at capturing the attention of the scientific community to make efforts in the development of such nonalternant cyclization reactions of alkynes.

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Section: Azulenes From Transition Metal‐catalyzed Formal Crossed [2+2...mentioning

confidence: 99%

Direct Access to Functionalized Azulenes and Pseudoazulenes via Unconventional Alkyne Cyclization Reactions

Wang

2023

Chemistry An Asian Journal

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“…Thirty-three gold(III) complexes of the [(C^C)Au(NHC/PPh 3 )L] + and [(C^N^C)AuL] + type were designed with L being the pyridine ligand of interest (Scheme ). These (C^C) and (C^N^C) chelating ligands are known for their high stability − and a large panel of applications in fundamental organometallic chemistry, , photoluminescence, − and biology. ,, Three scaffolds were chosen in order to access a large range of electronic effects. Aryl ligands (complexes 1 and 2 ) are indeed known to have a higher trans influence compared to N -donor ligands (complexes 3 ) …”

Section: Introductionmentioning

confidence: 99%

Bond-Dissociation Energies to Probe Pyridine Electronic Effects on Organogold(III) Complexes: From Methodological Developments to Application in π-Backdonation Investigation and Catalysis

Bourehil,

Soep,

Seng

et al. 2023

Inorg. Chem.

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In this work, we report on the synthesis of several organogold(III) complexes based on 4,4′-diterbutylbiphenyl (C^C) and 2,6-bis(4-terbutylphenyl)pyridine (C^N^C) ligands and bond with variously substituted pyridine ligands (pyrR). Altogether, 33 complexes have been prepared and studied with mass spectrometry using higher-energy collision dissociation (HCD) in an Orbitrap mass spectrometer. A complete methodology including the kinetic modeling of the dissociation process based on the Rice− Ramsperger−Kassel−Marcus (RRKM) statistical method is proposed to obtain critical energies E 0 of the pyrR loss for all complexes. The capacity of these E 0 values to describe the pyridine ligand effect is further explored, at the same time as more classical descriptors such as 1 H pyridinic NMR shift variation upon coordination and Au−N pyrR bond length measured by X-ray diffraction. An extensive theoretical work, including density functional theory (DFT) and domain-based local pair natural orbital coupled-cluster theory (DLPNO-CCSD(T)) methods, is also carried out to provide bond-dissociation energies, which are compared to experimental results. Results show that dissociation energy outperforms other descriptors, in particular to describe ligand effects over a large electronic effect range as seen by confronting the results to the pyrR pK a values. Further insights into the Au−N pyrR bond are obtained through an energy decomposition analysis (EDA) study, which confirms the isolobal character of Au + with H + . Finally, the correlation between the lability of the pyridine ligands toward the catalytic efficiency of the complexes could be demonstrated in an intramolecular hydroarylation reaction of alkyne. The results were rationalized considering both pre-catalyst activation and catalyst reactivity. This study establishes the possibility of correlating dissociation energy, which is a gas-phase descriptor, with condensed-phase parameters such as catalysis efficiency. It therefore holds great potential for inorganic and organometallic chemistry by opening a convenient and easy way to evaluate the electronic influence of a ligand toward a metallic center.

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Synthetic Strategies for the Preparation of Gold‐based Anticancer Agents

Gukathasan

Awuah

2022

Encyclopedia of Inorganic and Bioinorganic Chemistry

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Gold (Au) complexes attained an exceptional reach as new metal‐based anticancer agents in recent years. The FDA‐approved Au I complex auranofin [(2,3,4,6‐tetra‐ O ‐acetyl‐1‐thio‐β‐ d ‐glucopyranose (triethylphosphoranylidene)gold(I)] displays efficacious chemotherapeutic potential in phase I and II clinical trials for both liquid and solid tumors. Ignited by the success of auranofin as an anticancer agent, new designs and synthetic processes toward Au I and Au III complexes for unique biomedical applications are actively ongoing. In the past few years, Au III complexes have become attractive as premised on promising antitumor preclinical studies despite bottlenecks associated with stability and biological target identification. Advancement of gold complexes to the clinic will require agents with improved anticancer potency, unambiguous biological target, pharmacokinetic profile, and optimal stability. Thus, ligand tuning and innovative synthetic chemistry coupled with rigorous biological characterization are crucial. In this article, an overview of known synthetic strategies for the synthesis of gold anticancer complexes is presented. Primary focus on the synthesis of Au I and Au III complexes along with anticancer outcomes is outlined. This article presents medicinal inorganic chemists with an armory of synthetic tools and purification protocols to readily access highly potent gold anticancer agents.

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Gold(III) Meets Azulene: A Class of [(^tBuC^{^∧}N^{^∧}C)Au^III(azulenyl)] Pincer Complexes

Cited by 7 publications

References 61 publications

Direct Access to Functionalized Azulenes and Pseudoazulenes via Unconventional Alkyne Cyclization Reactions

Direct Access to Functionalized Azulenes and Pseudoazulenes via Unconventional Alkyne Cyclization Reactions

Bond-Dissociation Energies to Probe Pyridine Electronic Effects on Organogold(III) Complexes: From Methodological Developments to Application in π-Backdonation Investigation and Catalysis

Synthetic Strategies for the Preparation of Gold‐based Anticancer Agents

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