New applications of superacidic pyramidal boranes

A collaboration between three research groups belonging to the NISM institute (Namur Institute of Structured Matter) of the University of Namur coordinated by Prof. Guillaume Berionni and Dr. Aurélien Chardon (Chargé de recherché Postdoctorant FNRS) recently lead to the discovery of novel classes of non-planar boron superacids with unprecedented structure and reactivities (read the paper in Angewandte Chemie).

Trivalent organoboron compounds are ubiquitous Lewis acids widely used in homogeneous and heterogenous catalysis, and have a central role in materials science, chemical catalysis, supramolecular chemistry and drug discovery. According to fundamental chemical predictions models, trivalent organoboron compounds adopt a classical trivalent planar geometry.

The RCO (organic chemistry, reactivity and catalysis), the LCT (computational chemistry) and the CBS (X-ray diffractometry) research groups discovered that some unusually pyramidal boron compounds displayed the most Lewis acidic property ever observed among boranes. Arnaud Osi (PhD student funded by a FRIA scholarship from the FNRS) demonstrated that these boron superacids can even react with the strong covalent C-H, C-Si and C-C bonds of aromatic and aliphatic molecules, resulting in the formation of highly valuable chemical building blocks.

Such challenging chemical transformations are indicating the promising potential of pyramidal boron superacids in catalysis, since they display comparable reactivity to that of some transitions metals complexes.

Main authors:

  • G. Berionni, corresponding author (University of Namur, RCO laboratory, NISM Institute)
  • A. Chardon, corresponding author (University of Namur, RCO laboratory, NISM Institute)
  • Arnaud Osi, first author (University of Namur, RCO laboratory, NISM Institute)

Collaborators:

  • Damien Mahaut, FRIA PhD student (University of Namur, LCT/RCO laboratory, NISM Institute)
  • B. Champagne (University of Namur, LCT laboratory, NISM Institute)
  • N. Tumanov (University of Namur, CBS laboratory, NISM Institute)
  • J. Wouters (University of Namur, CBS laboratory, NISM Institute)
  • L. Fusaro (University of Namur, CMA laboratory, NISM Institute)

Article Online : https://onlinelibrary.wiley.com/doi/10.1002/anie.202112342