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1. The contrasting reactivity of trans - vs. cis -azobenzenes (ArNNAr) with benzynes

   https://doi.org/10.1039/d3sc02253f  

   Sneddon, Dorian S.; Hoye, Thomas R. (June 2023, Chemical Science)

   We report here a study that has revealed two distinct modes of reactivity of azobenzene derivatives (ArNNAr) with benzynes, depending on whether the aryne reacts with a trans - or a cis -azobenzene geometric isomer. Under thermal conditions, trans -azobenzenes engage benzyne via an initial [2 + 2] trapping event, a process analogous to known reactions of benzynes with diarylimines (ArCNAr). This is followed by an electrocyclic ring opening/closing sequence to furnish dihydrophenazine derivatives, subjects of contemporary interest in other fields ( e.g. , electronic and photonic materials). In contrast, when the benzyne is attacked by a cis -azobenzene, formation of aminocarbazole derivatives occurs via an alternative, net (3 + 2) pathway. We have explored these complementary orthogonal processes both experimentally and computationally. 

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2. Synthesis, Structure, and Reactivity of Copper(I) Proazaphosphatrane Complexes

   https://doi.org/10.1021/acs.inorgchem.4c04779  

   Hoskins-Harris, Jack_E; Kotera, Kiiko; Hoilette, Jr., Donovan_A; Apostolou, William_E; Osenga, Vicky_A; Thomas, Jared_I; Schley, Nathan_D; Donald, Kelling_J; Johnson, Miles_W (January 2025, Inorganic Chemistry)
3. Engendering reactivity at group 5-heteroatom multiple bonds via π-loading

   https://doi.org/10.1039/D2SC02706B  

   Fostvedt, Jade I.; Mendoza, Jocelyne; Lopez-Flores, Sacy; Alcantar, Diego; Bergman, Robert G.; Arnold, John (July 2022, Chemical Science)

   In this Perspective, we discuss the strategy of π-loading, i.e. , coordination of two or more strongly π-donating ligands to a single metal center, as it applies to promoting reactivity at group 5 transition metal-imido groups. When multiple π-donor ligands compete to interact with the same symmetrically-available metal d π orbitals, the energy of the imido-based frontier molecular orbitals increases, leading to amplified imido-based reactivity. This strategy is of particular relevance to group 5 metals, as mono(imido) complexes of these metals tend to be inert at the imido group. Electronic structure studies of group 5 bis(imido) complexes are presented, and examples of catalytically and stoichiometrically active group 5 bis(imido) and chalcogenido–imido complexes are reviewed. These examples are intended to encourage future work exploring π-loaded bis(imido) systems of the group 5 triad. 

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4. Synthesis and Reactivity of a Dimeric Ni(I) Methyl Complex

   https://doi.org/10.1021/acs.organomet.2c00188  

   Witzke, Ryan J.; Tilley, T. Don (June 2022, Organometallics)
5. Metal- versus ligand-centered reactivity of a cobalt-phenylenediamide complex with electrophiles

   https://doi.org/10.1039/d4dt01655f  

   Zou, Minzhu; Kuruppu, Sewwandi; Emge, Thomas J; Waldie, Kate M (August 2024, Dalton Transactions)

   A cobalt complex with a phenylenediamide redox-active ligand reacts with an electrophilic trifluoromethyl source to generate a robust Co–CF₃bond, while in contrast, treatment with alkyl electrophiles occurs at the ligand scaffold. 

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