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1. Catalytic reduction of aryl trialkylammonium salts to aryl silanes and arenes

   https://doi.org/10.1039/c9sc01083a  

   Rand, Alexander W.; Montgomery, John (January 2019, Chemical Science)

   A new approach for the reduction of aryl ammonium salts to arenes or aryl silanes using nickel catalysis is reported. This method displays excellent ligand-controlled selectivity based on the N-heterocyclic carbene (NHC) ligand employed. Utilizing a large NHC in non-polar solvents generates aryl silanes, while small NHCs in polar solvents promote reduction to arenes. Several classes of aryl silanes can be accessed from simple aniline building blocks, including those useful for cross-couplings, oxidations, and halogenations. The reaction conditions are mild, functional group tolerant, and provide efficient access to a variety of benzene derivatives. 

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2. Visible‐Light‐Induced Palladium‐Catalyzed Generation of Aryl Radicals from Aryl Triflates

   https://doi.org/10.1002/ange.201915962  

   Ratushnyy, Maxim; Kvasovs, Nikita; Sarkar, Sumon; Gevorgyan, Vladimir (April 2020, Angewandte Chemie)

   Abstract A mild visible‐light‐induced Pd‐catalyzed intramolecular C−H arylation of amides is reported. The method operates by cleavage of a C(sp²)−O bond, leading to hybrid aryl Pd‐radical intermediates. The following 1,5‐hydrogen atom translocation, intramolecular cyclization, and rearomatization steps lead to valuable oxindole and isoindoline‐1‐one motifs. Notably, this method provides access to products with readily enolizable functional groups that are incompatible with traditional Pd‐catalyzed conditions. 

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3. Ruthenium-Catalyzed Reductive Cleavage of Unstrained Aryl–Aryl Bonds: Reaction Development and Mechanistic Study

   https://doi.org/10.1021/jacs.9b11605  

   Zhu, Jun; Chen, Peng-hao; Lu, Gang; Liu, Peng; Dong, Guangbin (October 2019, Journal of the American Chemical Society)
4. A Review of the Functional Roles of the Zebrafish Aryl Hydrocarbon Receptors

   https://doi.org/10.1093/toxsci/kfaa143  

   Shankar, Prarthana; Dasgupta, Subham; Hahn, Mark E; Tanguay, Robyn L (September 2020, Toxicological Sciences)

   null (Ed.)

   Abstract Over the last 2 decades, the zebrafish (Danio rerio) has emerged as a stellar model for unraveling molecular signaling events mediated by the aryl hydrocarbon receptor (AHR), an important ligand-activated receptor found in all eumetazoan animals. Zebrafish have 3 AHRs—AHR1a, AHR1b, and AHR2, and studies have demonstrated the diversity of both the endogenous and toxicological functions of the zebrafish AHRs. In this contemporary review, we first highlight the evolution of the zebrafish ahr genes, and the characteristics of the receptors including developmental and adult expression, their endogenous and inducible roles, and the predicted ligands from homology modeling studies. We then review the toxicity of a broad spectrum of AHR ligands across multiple life stages (early stage, and adult), discuss their transcriptomic and epigenetic mechanisms of action, and report on any known interactions between the AHRs and other signaling pathways. Through this article, we summarize the promising research that furthers our understanding of the complex AHR pathway through the extensive use of zebrafish as a model, coupled with a large array of molecular techniques. As much of the research has focused on the functions of AHR2 during development and the mechanism of TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) toxicity, we illustrate the need to address the considerable knowledge gap in our understanding of both the mechanistic roles of AHR1a and AHR1b, and the diverse modes of toxicity of the various AHR ligands. 

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5. Homoleptic Aryl Complexes of Uranium (IV)

   https://doi.org/10.1002/anie.201905423  

   Wolford, Nikki J.; Sergentu, Dumitru‐Claudiu; Brennessel, William W.; Autschbach, Jochen; Neidig, Michael L. (June 2019, Angewandte Chemie International Edition)

   Abstract The synthesis and characterization of sterically unencumbered homoleptic organouranium aryl complexes containing U−C σ‐bonds has been of interest to the chemical community for over 70 years. Reported herein are the first structurally characterized, sterically unencumbered homoleptic uranium (IV) aryl‐ate species of the form [U(Ar)₆]²⁻(Ar=Ph,p‐tolyl,p‐Cl‐Ph). Magnetic circular dichroism (MCD) spectroscopy and computational studies provide insight into electronic structure and bonding interactions in the U−C σ‐bond across this series of complexes. Overall, these studies solve a decades‐long challenge in synthetic uranium chemistry, enabling new insight into electronic structure and bonding in organouranium complexes. 

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