Publications by authors named "Brandon L Frey"

ConspectusHypervalent iodine reagents find application as selective chemical oxidants in a diverse array of oxidative transformations. The utility of these reagents is often ascribed to (1) the proclivity to engage being selective two-electron redox transformations; (2) facile ligand exchange at the three-centered, four-electron (3c-4e) hypervalent iodine-ligand (I-X) bonds; and (3) the hypernucleofugacity of aryl iodides. One-electron redox and iodine radical chemistry is well-precedented in the context of inorganic hypervalent iodine chemistry─for example, in the iodide-triiodide couple that drives dye-sensitized solar cells.

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Article Synopsis
  • The study shows how sequential disproportionation reactions can gather two- or four electron-holes around a hypervalent iodine center.
  • Disproportionation of an iodanyl radical produced during electrochemical processes results in an iodosylbenzene compound.
  • Further disproportionation of this compound allows for the formation of an iodoxybenzene, illustrating a method for achieving multielectron oxidation through targeted disproportionation.
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Small molecule redox mediators convey interfacial electron transfer events into bulk solution and can enable diverse substrate activation mechanisms in synthetic electrocatalysis. Here, we report that 1,2-diiodo-4,5-dimethoxybenzene is an efficient electrocatalyst for C-H/E-H coupling that operates at as low as 0.5 mol % catalyst loading.

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Development of new electrosynthetic chemistry promises to impact the efficiency and sustainability of organic synthesis. Here we demonstrate that anodically generated hypervalent iodine intermediates effectively couple interfacial electron transfer with oxidative C-H/N-H coupling chemistry. The developed hypervalent iodine electrocatalysis is applicable in both intra- and intermolecular C-N bond-forming reactions.

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We report a topology-guided, precise insertion of three distinct secondary linkers into a zirconium-based metal-organic framework, NPF-300. Constructed from a tetratopic linker L and Zr cluster, NPP-300 exhibits a unique scu topology and certain flexibility along the crystallographic a axis, and in conjunction with the conformation change of the primary ligand, is able to accommodate the stepwise insertion of three different secondary linkers along the a and c axes. Size-matching and mechanic strain of the resulting framework are two important factors that determine the chemical stability of the inserted linkers.

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