Controlled Generation of 9-Boratriptycene by Lewis Adduct Dissociation: Accessing a Non‐Planar Triarylborane

Aurélien Chardon; Arnaud Osi; Damien Mahaut; Thu Hong Doan; Nikolay Tumanov; Johan Wouters; Luca Fusaro; Benoît Champagne; Guillaume Berionni

doi:10.1002/ange.202003119

Controlled Generation of 9-Boratriptycene by Lewis Adduct Dissociation: Accessing a Non‐Planar Triarylborane

Research output: Contribution to journal › Article › peer-review

Abstract

A highly bent triarylborane, 9-boratriptycene, was generated in solution by selective protodeboronation of the corresponding tetra-aryl boron ate complex with the strong Brønsted acid HNTf₂. The iptycene core confers enhanced Lewis acidity to 9-boratriptycene, making it unique in terms of structure and reactivity. We studied the stereoelectronic properties of 9-boratriptycene by quantifying its association with small N- and O-centered Lewis bases, as well as with sterically hindered phosphines. The resultant Lewis adducts exhibited unique structural, spectroscopic, and photophysical properties. Beyond the high pyramidalization of the 9-boratriptycene scaffold and its low reorganization energy upon Lewis base coordination, quantum chemical calculations revealed that the absence of π donation from the triptycene aryl rings to the boron vacant p_z orbital is one of the main reasons for its high Lewis acidity.

Original language	English
Article number	10.1002/ange.202003119
Pages (from-to)	12502-12506
Number of pages	5
Journal	Angewandte Chemie
Volume	132
Issue number	30
DOIs	https://doi.org/10.1002/ange.202003119
Publication status	Published - 20 Jul 2020

Funding

We acknowledge the University of Namur, the Namur Institute of Structured Matter (NISM), and the Fond National de la Recherche Scientifique (FNRS grant F.4513.18 for GB and FRIA PhD grants for A.O. and D.M.) for financial support. We thank the PC 2 technological platform for access to characterization instruments. The calculations were performed on the computers of the Consortium des Équipements de Calcul Intensif and particularly those of the High‐Performance Computing Platform, which are supported by the FNRS‐FRFC, the Walloon Region, and the University of Namur (Conventions No. GEQ U.G006.15, U.G018.19, 1610468, and RW/GEQ2016). We acknowledge Prof. H. Mayr and Dr. A. R. Ofial (LMU University, Munich), Dr. S. Lakhdar (Paul Sabatier University, Toulouse), Prof. A. Krief, and Dr. N. Tumanova for helpful discussions, and Lei Hu for the sample of 9‐phosphatriptycene.

Keywords

Lewis adducts
non-planar boron Lewis acids
triarylborane
triptycene

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10.1002/ange.202003119

Cite this

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title = "Controlled Generation of 9-Boratriptycene by Lewis Adduct Dissociation: Accessing a Non‐Planar Triarylborane",

abstract = "A highly bent triarylborane, 9-boratriptycene, was generated in solution by selective protodeboronation of the corresponding tetra-aryl boron ate complex with the strong Br{\o}nsted acid HNTf2. The iptycene core confers enhanced Lewis acidity to 9-boratriptycene, making it unique in terms of structure and reactivity. We studied the stereoelectronic properties of 9-boratriptycene by quantifying its association with small N- and O-centered Lewis bases, as well as with sterically hindered phosphines. The resultant Lewis adducts exhibited unique structural, spectroscopic, and photophysical properties. Beyond the high pyramidalization of the 9-boratriptycene scaffold and its low reorganization energy upon Lewis base coordination, quantum chemical calculations revealed that the absence of π donation from the triptycene aryl rings to the boron vacant pz orbital is one of the main reasons for its high Lewis acidity.",

keywords = "Lewis adducts, non-planar boron Lewis acids, triarylborane, triptycene",

author = "Aur{\'e}lien Chardon and Arnaud Osi and Damien Mahaut and Doan, \{Thu Hong\} and Nikolay Tumanov and Johan Wouters and Luca Fusaro and Beno{\^i}t Champagne and Guillaume Berionni",

year = "2020",

month = jul,

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doi = "10.1002/ange.202003119",

language = "English",

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T1 - Controlled Generation of 9-Boratriptycene by Lewis Adduct Dissociation

T2 - Accessing a Non‐Planar Triarylborane

AU - Chardon, Aurélien

AU - Osi, Arnaud

AU - Mahaut, Damien

AU - Doan, Thu Hong

AU - Tumanov, Nikolay

AU - Wouters, Johan

AU - Fusaro, Luca

AU - Champagne, Benoît

AU - Berionni, Guillaume

PY - 2020/7/20

Y1 - 2020/7/20

N2 - A highly bent triarylborane, 9-boratriptycene, was generated in solution by selective protodeboronation of the corresponding tetra-aryl boron ate complex with the strong Brønsted acid HNTf2. The iptycene core confers enhanced Lewis acidity to 9-boratriptycene, making it unique in terms of structure and reactivity. We studied the stereoelectronic properties of 9-boratriptycene by quantifying its association with small N- and O-centered Lewis bases, as well as with sterically hindered phosphines. The resultant Lewis adducts exhibited unique structural, spectroscopic, and photophysical properties. Beyond the high pyramidalization of the 9-boratriptycene scaffold and its low reorganization energy upon Lewis base coordination, quantum chemical calculations revealed that the absence of π donation from the triptycene aryl rings to the boron vacant pz orbital is one of the main reasons for its high Lewis acidity.

AB - A highly bent triarylborane, 9-boratriptycene, was generated in solution by selective protodeboronation of the corresponding tetra-aryl boron ate complex with the strong Brønsted acid HNTf2. The iptycene core confers enhanced Lewis acidity to 9-boratriptycene, making it unique in terms of structure and reactivity. We studied the stereoelectronic properties of 9-boratriptycene by quantifying its association with small N- and O-centered Lewis bases, as well as with sterically hindered phosphines. The resultant Lewis adducts exhibited unique structural, spectroscopic, and photophysical properties. Beyond the high pyramidalization of the 9-boratriptycene scaffold and its low reorganization energy upon Lewis base coordination, quantum chemical calculations revealed that the absence of π donation from the triptycene aryl rings to the boron vacant pz orbital is one of the main reasons for its high Lewis acidity.

KW - Lewis adducts

KW - non-planar boron Lewis acids

KW - triarylborane

KW - triptycene

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DO - 10.1002/ange.202003119

M3 - Article

SN - 0044-8249

VL - 132

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EP - 12506

JO - Angewandte Chemie

JF - Angewandte Chemie

IS - 30

M1 - 10.1002/ange.202003119

ER -

Controlled Generation of 9-Boratriptycene by Lewis Adduct Dissociation: Accessing a Non‐Planar Triarylborane

Abstract

Funding

Keywords

Access to Document

Other files and links

Embargoed Document

Fingerprint

HydrogenActive: Sterically hindered 9-phosphatriptycenes as Lewis bases in frustrated Lewis pair chemistry: synthesis, application to hydrogenation reactions and computational investigations

CÉCI – Consortium of high performance computing centers

High Performance Computing Technology Platform

Physical Chemistry and characterization(PC2)

Synthesis of sterically hindered phosphatriptycenes and computational investigation of their properties in the context of frustrated lewis pair chemistry

Cite this

Controlled Generation of 9-Boratriptycene by Lewis Adduct Dissociation: Accessing a Non‐Planar Triarylborane

Abstract

Funding

Keywords

Access to Document

Other files and links

Embargoed Document

Fingerprint

Projects

HydrogenActive: Sterically hindered 9-phosphatriptycenes as Lewis bases in frustrated Lewis pair chemistry: synthesis, application to hydrogenation reactions and computational investigations

CÉCI – Consortium of high performance computing centers

Equipment

High Performance Computing Technology Platform

Physical Chemistry and characterization(PC2)

Student theses

Synthesis of sterically hindered phosphatriptycenes and computational investigation of their properties in the context of frustrated lewis pair chemistry

Cite this