Open Access
CC BY 4.0 · Organic Materials 2025; 07(03): 9-36
DOI: 10.1055/a-2603-4217
Emerging Stars in Organic and Polymer Materials
Review

Synthetic Methods for the Construction of 1,2-Azaborole-Containing Polycyclic Aromatic Hydrocarbons

Patrick T. Geppert#
a   Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
,
Daniel Volland#
a   Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
,
Klaudia Szkodzińska
a   Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
,
a   Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
› Institutsangaben


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Abstract

Boron-doped polycyclic aromatic hydrocarbons have emerged as a prominent class of compounds due to the unique properties that can be achieved through the incorporation of boron, often paired with another heteroatom, a combination that makes them attractive for a range of applications. The benefit of doping with these heteroatoms is also evident in 1,2-azaboroles, a subclass of B-containing compounds, consisting of five-membered unsaturated heterocycles with dative boron–nitrogen bonds. The donation of electron density from nitrogen to boron renders the molecules electronically saturated and endows them with the stability that is a prerequisite for their application in organic electronics, photovoltaics, or bioimaging. The development of these compounds, first described in the 1960s, has been particularly intensive over the past two decades, driven by their photoresponsive and luminescent properties. This review aims to provide a comprehensive overview of the synthetic methodologies employed in the construction of 1,2-azaboroles. In addition to classical approaches, such as nitrogen-directed electrophilic C – H borylation or lithiation–transmetalation of prefunctionalized substrates, we discuss less commonly used methods and protocols that are limited to specific starting materials, thus demonstrating a large available repertoire of synthetic tools to access these compounds.

1 Introduction

2 Synthetic Approaches

2.1 Lithiation-Transmetalation

2.2 Electrophilic C–H Borylation

2.3 Transition Metal-Catalyzed C–H Borylation

2.4 Cycloaddition

2.5 Photoisomerization

2.6 Hydroboration

2.7 Coordination-Cyclization

2.8 Nucleophilic Aromatic Substitution

2.9 Silicon–Boron Exchange

3 Conclusion and Outlook

# These authors contributed equally to this work.




Publikationsverlauf

Eingereicht: 05. April 2025

Angenommen: 05. Mai 2025

Accepted Manuscript online:
08. Mai 2025

Artikel online veröffentlicht:
09. Juli 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/).

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