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Unlocking Heteroaromatic Ring Systems through Chalcogen Insertion into Boroles.

Tobias Bischof^1,2, Nele Wieprecht^1,2, Sonja Fuchs^1,2

¹Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.

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|December 4, 2023

Summary

This summary is machine-generated.

Researchers explored how annulated borole derivatives react with oxygen, sulfur, and selenium. The 9-o-carboranyl-substituted 9-borafluorene derivative successfully formed new chalcogen-containing heteroarenes, including a novel 1,2-selenaborinine.

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Area of Science:

Organometallic Chemistry
Heterocyclic Chemistry
Materials Science

Background:

Borole derivatives are versatile building blocks in organic synthesis.
Chalcogen insertion reactions are crucial for creating novel heterocyclic compounds.
Annulated borole systems offer unique electronic and structural properties.

Purpose of the Study:

To investigate the reactivity of substituted 9-borafluorenes and fused thiophene-benzene derivatives towards chalcogen insertion.
To synthesize novel chalcogen-containing heteroarenes, including selenium derivatives.
To evaluate the aromaticity of newly synthesized heterocyclic compounds.

Main Methods:

Synthesis of various annulated borole derivatives.
Chalcogen (O, S, Se) insertion reactions.
Spectroscopic characterization of products.
Computation of nucleus-independent chemical shift (NICS) values.

Main Results:

The 9-o-carboranyl-substituted 9-borafluorene selectively yielded a complete set of O, S, and Se heteroarenes.
The first 1,2-selenaborinine derivative was successfully synthesized.
NICS values indicated aromaticity in the synthesized heterocyclic analogues.

Conclusions:

The 9-o-carboranyl substituent is key for achieving complete chalcogen insertion in these borole systems.
This study expands the scope of heterocyclic chemistry by introducing novel selenium-containing boroles.
The findings provide insights into the aromatic character of these unique heterocycles.