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  1. Abstract

    The Lewis superacid, bis(1‐methyl‐ortho‐carboranyl)borane, is rapidly accessed in two steps. It is a very effective hydroboration reagent capable of B−H addition to alkenes, alkynes, and cyclopropanes. To date, this is the first identified Lewis superacidic secondary borane and most reactive neutral hydroboration reagent.

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  2. Abstract

    The synthesis of tris(ortho‐carboranyl)borane (BoCb3), a single site neutral Lewis superacid, in one pot from commercially available materials is achieved. The high fluoride ion affinity (FIA) confirms its classification as a Lewis superacid and the Gutmann‐Beckett method as well as adducts with Lewis bases indicate stronger Lewis acidity over the widely used fluorinated aryl boranes. The electron withdrawing effect ofortho‐carborane and lack of pi‐delocalization of the LUMO rationalize the unusually high Lewis acidity. Catalytic studies indicate that BoCb3is a superior catalyst for promoting C−F bond functionalization reactions than tris(pentafluorophenyl)borane [B(C6F5)3].

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  3. Abstract

    The 9‐borataphenanthrene anion is easily accessed by deprotonation of a 9,10‐dihydro‐9‐boraphenanthrene and its diverse reactivity is investigated. Alkylation occurs at the carbon atom adjacent to boron, and room temperature hydroboration occurs across the B=C bond. The π‐manifold of the central BC5ring coordinates to chromium in an η6fashion while only the B=C unit binds η2to gold, indicating versatility of the 9‐borataphenanthrene anion as a ligand. Supporting calculations rationalize the reactivity and aromaticity is corroborated by nucleus‐independent chemical shift (NICS) indices.

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  4. Carborane fused boron doped polycyclic aromatic hydrocarbons were accessed by dehydrobrominative and dehydrogenative borylation.

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    Free, publicly-accessible full text available May 22, 2025
  5. Free, publicly-accessible full text available March 18, 2025
  6. Free, publicly-accessible full text available November 1, 2024
  7. The additions of the phosphinoboronate ester Ph2PBpin to an antiaromatic borole and a borafluorene is reported. The Lewis acid/base adducts are obtained in excellent yields and represent the first P-donor adducts of Ph2PBpin. 
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    Free, publicly-accessible full text available October 27, 2024
  8. Free, publicly-accessible full text available August 21, 2024
  9. Reactions of tris(ortho-carboranyl)borane with Lewis bases reveals only small bases bind. The tremendous bulk and Lewis acidity is leveraged in frustrated Lewis pair Si–H cleavage with a wider range of Lewis bases and greater efficacy than B(C6F5)3.

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  10. Nickel K- and L 2,3 -edge X-ray absorption spectra (XAS) are discussed for 16 complexes and complex ions with nickel centers spanning a range of formal oxidation states from II to IV. K-edge XAS alone is shown to be an ambiguous metric of physical oxidation state for these Ni complexes. Meanwhile, L 2,3 -edge XAS reveals that the physical d-counts of the formally Ni IV compounds measured lie well above the d 6 count implied by the oxidation state formalism. The generality of this phenomenon is explored computationally by scrutinizing 8 additional complexes. The extreme case of NiF 6 2− is considered using high-level molecular orbital approaches as well as advanced valence bond methods. The emergent electronic structure picture reveals that even highly electronegative F-donors are incapable of supporting a physical d 6 Ni IV center. The reactivity of Ni IV complexes is then discussed, highlighting the dominant role of the ligands in this chemistry over that of the metal centers. 
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