A room-temperature-stable electride and its reactivity: Reductive benzene/pyridine couplings and solvent-free Birch reductions

Nathan Davison, James A. Quirk, Floriana Tuna, David Collison, Hannes Michaels, George H. Morritt, Paul G. Waddell, Jamie A. Gould, Marina Freitag, James A. Dawson, Erli Lu

Research output: Contribution to journalArticlepeer-review

15 Citations (SciVal)
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Abstract

In this work, we report the synthesis of a room-temperature-stable electride (RoSE) reagent, namely K +(LiHMDS)e (1) (HMDS: 1,1,1,3,3,3-hexamethyldisilazide), from accessible starting materials (potassium metal and LiHMDS) via mechanochemical ball milling at 20 mmol scale. Despite its amorphous nature, the presence of anionic electrons in 1, key diagnostic criteria for an electride, was confirmed by both experimental and computational studies. Therefore, by definition, 1 is an electride. Utilizing its anionic electrons, electride reagent 1 exhibited a versatile reactivity profile that includes (1) mediation of C–H activation and C–C coupling of benzene and pyridine and (2) mediation of solvent-free Birch reduction. This work proves the concept of facile mechanochemical synthesis of a room-temperature-stable electride, and it introduces electride 1 to the synthetic chemistry community as a versatile reagent.

Original languageEnglish
Pages (from-to)576-591
Number of pages16
JournalChem
Volume9
Issue number3
Early online date1 Dec 2022
DOIs
Publication statusPublished - 9 Mar 2023

Bibliographical note

Funding Information:
The authors thank the Newcastle University Chemistry Technical Support Team (Dr. Laura McCorkindale, Dr. Amy Roberts, and Mr. Niall Straughan) for supporting their research. E.L. thanks Drs. Roly Armstrong and Keith Izod, as well as Profs. Michael Waring and Bernard Golding (all at Newcastle University), for their insightful discussions. E.L. J.A.D. and M.F. thank the Newcastle University Academic Track (NUAcT) Fellowship Scheme for financial support. N.D. thanks Newcastle University for a NUAcT PhD studentship. J.A.D. gratefully acknowledges the EPSRC (EP/V013130/1) for funding; via membership of the UK's HEC Materials Chemistry Consortium, which is funded by the EPSRC (EP/R029431), this work used the ARCHER2 UK National Supercomputing Service. E.L. thanks the EPSRC North East Centre of Energy Materials (NECEM) and the Royal Society of Chemistry Research Enablement Grant (E20-5153) for financial support to build the mechanochemistry facility. The authors thank the EPSRC National Research Facility for EPR Spectroscopy (NS/A000055/1) for EPR and magnetometry measurements. C.L.M. thanks the University of Bath for access to the Anatra and Balena High Performance Computing Services. This work is dedicated to the memory of Prof. James L. Dye (Michigan State University; 1927–2021), a pioneer in electride chemistry. N.D. and E.L. conceptualized the central idea and designed and conducted the syntheses and characterization. J.A.Q. and J.A.D. designed and conducted the AIRSS calculations for 1. F.T. and D.C. collected and analyzed the EPR and SQUID magnetometry data. C.L.M. designed and conducted the molecular geometries and the orbital and reaction intermediate calculations for 2. H.M. G.H.M. and M.F. collected and analyzed the electroconductivity data. P.G.W. and J.A.G. collected and analyzed the single-crystal and powder X-ray diffraction data, respectively. E.L. supervised the work, analyzed the data, and wrote the manuscript with contributions from all the authors. The authors declare no competing interests. We support inclusive, diverse, and equitable conduct of research.

Funding Information:
The authors thank the Newcastle University Chemistry Technical Support Team (Dr. Laura McCorkindale, Dr. Amy Roberts, and Mr. Niall Straughan) for supporting their research. E.L. thanks Drs. Roly Armstrong and Keith Izod, as well as Profs. Michael Waring and Bernard Golding (all at Newcastle University), for their insightful discussions. E.L., J.A.D., and M.F. thank the Newcastle University Academic Track (NUAcT) Fellowship Scheme for financial support. N.D. thanks Newcastle University for a NUAcT PhD studentship. J.A.D. gratefully acknowledges the EPSRC ( EP/V013130/1 ) for funding; via membership of the UK’s HEC Materials Chemistry Consortium, which is funded by the EPSRC ( EP/R029431 ), this work used the ARCHER2 UK National Supercomputing Service. E.L. thanks the EPSRC North East Centre of Energy Materials (NECEM) and the Royal Society of Chemistry Research Enablement Grant ( E20-5153 ) for financial support to build the mechanochemistry facility. The authors thank the EPSRC National Research Facility for EPR Spectroscopy ( NS/A000055/1 ) for EPR and magnetometry measurements. C.L.M. thanks the University of Bath for access to the Anatra and Balena High Performance Computing Services. This work is dedicated to the memory of Prof. James L. Dye (Michigan State University; 1927–2021), a pioneer in electride chemistry.

Publisher Copyright:
© 2022 The Author(s)

Keywords

  • Birch reduction
  • C–C coupling
  • C–H activation
  • SDG12: Responsible consumption and production
  • SDG3: Good health and well-being
  • benzene
  • electride
  • mechanochemistry
  • organic synthesis
  • pyridine
  • sustainability

ASJC Scopus subject areas

  • Biochemistry, medical
  • Materials Chemistry
  • Chemical Engineering(all)
  • Chemistry(all)
  • Biochemistry
  • Environmental Chemistry

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