Electron-Rich Monovalent Boron: A Platform for Metal Mimicry

• Applicant: Professor Dr. Holger Braunschweig
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2017 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 325229020

• Final Report Year: 2020

Final Report Abstract

This project has opened up huge opportunities for future research in our group. The TM-borylene chemistry, upon which the original proposal was based, has seen a large expansion of promising TM-borylene reagents, as well as a number of new modes of liberation of the borylene ligand using Lewis bases and other reagents such as chalcogens, leading to new (metal-free) monovalent boron compounds, iminoboranes as well as a number of new classes of boron-containing heterocycles. The metal-free chemistry of monovalent boron compounds, a more recent offshoot of this chemistry, has already witnessed some major breakthroughs such as the first fixation, reduction and dimerization of N2 at a main-group atom, and ultimately the confirmed one-pot synthesis of ammonium from N2 using this system. A huge number of possibilities beckon from these results in different directions, namely: (a) the use of monovalent boron species in the activation of other challenging small molecules, and (b) the development of the N2 fixation chemistry towards practical methods to prepare ammonia and other value-added nitrogencontaining compounds.

Publications

• Synthesis and Trapping of Iminoboranes via M=B/C=N Bond Metathesis, Angew. Chem. Int. Ed. 2017, 56, 7975–7979
  Nutz, Marco; Borthakur, Bitupon; Dewhurst, Rian D.; Deißenberger, Andrea; Dellermann, Theresa; Schäfer, Marius; Krummenacher, Ivo; Phukan, Ashwini K. & Braunschweig, Holger
  
• The First Boron-Tellurium Double Bond: Direct Insertion of Heavy Chalcogens into a Mn=B Double Bond, Angew. Chem. Int. Ed. 2017, 56, 15760–15763
  Liu, Siyuan; Légaré, Marc‐André; Auerhammer, Dominic; Hofmann, Alexander & Braunschweig, Holger
  
• A Boradiselenirane and a Boraditellurirane: Isolable Heavy Analogs of Dioxiranes and Dithiiranes, J. Am. Chem. Soc. 2018, 140, 11223–11226
  Liu, Siyuan; Légaré, Marc-André; Hofmann, Alexander & Braunschweig, Holger
  
• Nitrogen fixation and reduction at boron, Science 2018, 359, 896–900
  Légaré, Marc-André; Bélanger-Chabot, Guillaume; Dewhurst, Rian D.; Welz, Eileen; Krummenacher, Ivo; Engels, Bernd & Braunschweig, Holger
  
• Release of Isonitrile- and NHC-stabilized Borylenes from Group VI Terminal Borylene Complexes, Chem. Eur. J. 2018, 24, 6843–6847
  Nutz, Marco; Borthakur, Bitupon; Pranckevicius, Conor; Dewhurst, Rian D.; Schäfer, Marius; Dellermann, Theresa; Glaab, Fabian; Thaler, Melanie; Phukan, Ashwini K. & Braunschweig, Holger
  
• Metallomimetic Chemistry of Boron, Chem. Rev. 2019, 119, 8231–8261
  Légaré, Marc-André; Pranckevicius, Conor & Braunschweig, Holger
  
• Recent Advances in Boron-Centered Ligands and Their Transition Metal Complexes, Coord. Chem. Rev. 2019, 184–200
  Goettel, James T. & Braunschweig, Holger
  
• Synthesis of unsymmetrical B2E2 and B2E3 heterocycles by borylene insertion into boradichalcogeniranes, Chem. Sci. 2019, 10, 4662–4666
  Liu, Siyuan; Légaré, Marc-André; Hofmann, Alexander; Rempel, Anna; Hagspiel, Stephan & Braunschweig, Holger
  
• The reductive coupling of dinitrogen, Science 2019, 363, 1329–1332
  Légaré, Marc-André; Rang, Maximilian; Bélanger-Chabot, Guillaume; Schweizer, Julia I.; Krummenacher, Ivo; Bertermann, Rüdiger; Arrowsmith, Merle; Holthausen, Max C. & Braunschweig, Holger
  
• Boron: Its role in energy related research and applications, Angew. Chem. Int. Ed.
  Huang, Zhenguo; Wang, Suning; Dewhurst, Rian D.; Ignat'ev, Nikolai V.; Finze, Maik & Braunschweig, Holger