Intramolecular borylation via sequential B-Mes bond cleavage for the divergent synthesis of B,N,B-doped benzo[4]helicenes
Abstract
New symmetric and unsymmetric B,N,B-doped benzo[4]helicenes 3 - 6a/b have been achieved in good yields, using a three-step process, starting from N(tolyl)3 in a highly divergent manner (7 examples). A borinic acid functionalized 1,4-B,N- anthracene 1 was found to display unprecedented reactivity, acting as a convenient and highly effective precursor for selective formation of bromo substituted B,N,B-benzo[4]helicenes 2a/2b via intramolecular borylation and sequential B-Mes bond cleavage in presence of BBr3. Subsequent reaction of 2a/2b with Ar-Li provided a highly effective toolbox for the preparation of symmetrically/unsymmetrically functionalized B,N,B-helicenes. Their high photoluminescence quantum yields along with the small ∆EST suggest the potential as thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs).
Citation
Knöller , J , Meng , G , Wang , X , Hall , D , Pershin , A , Beljonne , D , Olivier , Y , Laschat , S , Zysman-Colman , E & Wang , S 2020 , ' Intramolecular borylation via sequential B-Mes bond cleavage for the divergent synthesis of B,N,B-doped benzo[4]helicenes ' , Angewandte Chemie International Edition , vol. Early View . https://doi.org/10.1002/anie.201912340
Publication
Angewandte Chemie International Edition
Status
Peer reviewed
ISSN
1433-7851Type
Journal article
Description
Authors thank the Natural Sciences and Engineering Research Council of Canada and the Leverhulme Trust (RPG-2016-47) for financial support. J. A. Knöller thanks the Baden Württemberg Stiftung for a scholarship as well as Queen's and Stuttgart University for enabling this research through the Dual Degree Masters program.Collections
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