Ingleson Group’s recent Angewandte paper highlighted as a Very Important Paper
Ingleson Group’s recent Angewandte paper highlighted as a Very Important Paper
The paper - ‘A Base-Free Two-Coordinate Oxoborane’ - was published last month in Angewandte Chemie International Edition in collaboration with Cate Anstöter. The paper was rated as outstanding by all reviewers for novelty and is significant for several reasons outlined below.
The creation of a novel chemical species: a base-free, two-coordinate oxoborane (R-BO) stabilized as a Lewis adduct with AlCl3 represents a notable advancement because previously, oxoboranes were only known to be isolable in complexes where they form a three-coordinate at boron structure containing a Lewis base.
Addressing Stability Challenges: Oxoboranes are typically transient and prone to trimerization under normal conditions. This study showcases that through coordination of a Lewis acid at oxygen, the oxoborane can remain monomeric, and is stable enough to be isolated. The origin of the stabilization is both kinetic and thermodynamic, highlighting a novel method to enhance the stability of a reactive species without the need for a Lewis base.
Unique Chemical Reactivity: The base-free oxoborane displays unique reactivity patterns, highlighted by its reaction with phenyl azide leading to the formation of an unusual boron heterocycle. Through collaboration with Dr. Anstöter, state of the art methods were used to understand the aromaticity within this unique heterocycle. This provides insights into the reactivity of oxoboranes that were previously not understood or observed.
Fundamental Understanding of Boron Chemistry: By providing an in-depth analysis, including computational data on the structure and bonding within the oxoborane, the study extends fundamental knowledge about boron chemistry, especially about the nature of the boron-oxygen multiple bonds and the effect of Lewis acid coordination on these bonds.
The findings also have broader implications for using Lewis acids to stabilize and manipulate otherwise transient multiply bonded main group species, which can open new pathways in the synthesis and study of otherwise fragile molecules in chemistry.
Overall, the paper marks a step forward in the chemistry of these boron compounds, particularly in understanding and manipulating oxoboranes, which are analogous to key organic functionalities like acylium cations but were previously much less stable and harder to study.
“I’m very pleased that our work has been highlighted in this way, thanks to Clement, Dominic, Gary and Cate for their work, and to the Mass Spec facility at the University of Edinburgh and Diamond Light Source. Thanks also to EPSRC for funding provided through the ‘Boron: Beyond the Reagent’ and ‘New Routes to Fluorocarbons using Fluoroboranes’ grants.”
Prof. Mike Ingleson