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Updated: Oct 6, 2025
10:44
Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
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Kinetic stabilization allows structural analysis of a benzoborirene
Marvin Sindlinger1, Markus Ströbele2, Cäcilia Maichle-Mössmer2
1Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany. holger.bettinger@uni-tuebingen.de.
Chemical Communications (Cambridge, England)
|January 20, 2022
Summary
Researchers synthesized a novel, strained benzoborirene using tert-butyl lithium reduction. This unique organoboron compound is the first of its kind to be fully characterized by X-ray crystallography.
Area of Science:
- Organometallic Chemistry
- Boron Chemistry
- Organic Synthesis
Background:
- Benzoborirenes are highly strained cyclic organoboron compounds.
- Their synthesis and characterization are challenging due to inherent instability.
- Previous studies lacked detailed structural information.
Purpose of the Study:
- To synthesize and characterize a novel benzoborirene derivative.
- To investigate the kinetic stabilization of strained boron compounds.
- To provide the first single-crystal X-ray crystallographic data for a benzoborirene.
Main Methods:
- Formal reduction of a (2-bromophenyl)chloro(terphenyl)borane precursor.
- Utilized tert-butyl lithium as the reducing agent at low temperatures.
- Characterization via single-crystal X-ray crystallography.
Main Results:
- Successfully synthesized a highly strained benzoborirene.
- The compound is kinetically stabilized by a bulky terphenyl substituent.
- The benzoborirene withstands heating up to 80 °C.
- The six-membered ring exhibits an anti-Mills-Nixon distortion.
Conclusions:
- This work reports the first fully characterized benzoborirene.
- The bulky terphenyl group provides significant kinetic stabilization.
- The structural data offers insights into the bonding and distortion in strained boron heterocycles.
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