15405
2017
eng
preprint
1
2017-10-19
--
--
CuOTf-mediated intramolecular diborene hydroarylation
Upon complexation to CuOTf, a PMe\(_3\)-stabilized bis(9-anthryl) diborene slowly undergoes an intramolecular hydroarylation reaction at room temperature. Subsequent triflation of the B–H bond with CuOTf, followed by a PMe\(_3\) transfer, finally yields a cyclic sp\(^2\)-sp\(^3\) boryl-substituted boronium triflate salt.
Chemical Communications
10.1039/C7CC07371B
urn:nbn:de:bvb:20-opus-154055
This is the pre-peer reviewed version of the following article: Chemical Communications, 2017, 11945-11947 which has been published at DOI: 10.1039/C7CC07371B.
669054
Chem. Commun., 2017, Advance Article, DOI: 10.1039/C7CC07371B
Deutsches Urheberrecht
Sunewang Rixin Wang
Merle Arrowsmith
Holger Braunschweig
Rian Dewhurst
Valerie Paprocki
Lena Winner
eng
uncontrolled
boron
eng
uncontrolled
C-H activation
eng
uncontrolled
transition metals
Anorganische Chemie
open_access
Institut für Anorganische Chemie
OpenAIRE
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/15405/Braunschweig_CuOTf-mediated_intramolecular_diborene_hydroarylation_ChemComm_2017_submitted_version.pdf
17860
2019
eng
preprint
1
2019-03-26
--
--
Phosphine-Stabilized Diiododiborenes: Isolable Diborenes with Six Labile Bonds
The lability of B=B, B-P and B-halide bonds is combined in the syntheses of the first diiododiborenes. In a series of reactivity tests, these diiododiborenes demonstrate cleavage of all six of their central bonds in different ways, leading to products of B=B hydrogenation and dihalogenation as well as halide exchange.
Angewandte Chemie, International Edition
10.1002/anie.201814230
urn:nbn:de:bvb:20-opus-178608
This is the pre-peer reviewed version of the following article: J. H. Muessig, M. Thaler, R. D. Dewhurst, V. Paprocki, J. Seufert, J. D. Mattock, A. Vargas, H. Braunschweig, Angew. Chem. Int. Ed. 2019, 58, 4405, which has been published in final form at https://doi.org/10.1002/anie.201814230. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.
669054
Angewandte Chemie International Edition 2019, 58, 4405. https://doi.org/10.1002/anie.201814230
false
true
Deutsches Urheberrecht
Jonas H. Muessig
Melanie Thaler
Rian D. Dewhurst
Valerie Paprocki
Jens Seufert
James D. Mattock
Alfredo Vargas
Holger Braunschweig
eng
uncontrolled
boron
eng
uncontrolled
low-valent main-group species
eng
uncontrolled
iodine
eng
uncontrolled
multiple bonding
eng
uncontrolled
1,2-additions
Anorganische Chemie
open_access
Institut für Anorganische Chemie
OpenAIRE
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/17860/Braunschweig_Diiododiborenes_Angew_Chemie_Internat_Ed_2019.pdf
19370
2020
deu
doctoralthesis
1
2020-01-09
--
2019-12-13
Synthese und Reaktivität neuartiger Komplexe mit carbo- und heterocyclischen pi-Liganden
Synthesis and reactivity of novel complexes featuring carbo- and heterocyclic pi-ligands
Die vorliegende Arbeit befasst sich mit der Synthese, Charakterisierung und Reaktivität von Nebengruppen-Metallkomplexen, die mindestens einen pi-koordinierenden Liganden tragen. Im ersten Abschnitt liegt der Fokus auf heteroleptischen Systemen mit carbocyclischen Liganden, zu deren Synthese die gängige Methodik der Salzeliminierung herangezogen wird. Das Metallierungsverhalten dieser Komplexe, sowie die Reaktivität von Komplexen mit reduktionsstabilen funktionellen Gruppen an den Ligandensystemen wird untersucht. Der zweite Abschnitt behandelt die Redox- und Koordinationseigenschaften des CAAC-stabilisierten 1,4 Diborabenzols, wobei Alkali-Metalle, Gruppe 10 Metalle, Lanthanoide, sowie die Actinoide Thorium und Uran untersucht werden.
The present work deals with the synthesis, characterization and reactivity studies of subgroup metal complexes bearing at least one sandwich-type carbo- or heterocyclic ligand. The first chapter covers studies on the synthesis of heteroleptic sandwich complexes employing the well-established salt-metathesis strategy. The metalation properties as well as the reactivity of the complexes is investigated. The second chapter of this work discusses further studies on the redox and coordination properties of neutral, CAAC-stabilized 1,4-diborabenze. To this end reactions with alkali and group 10 metals, elements of the lanthanides as well as the actinide metals Thorium and Uranium are reviewed.
urn:nbn:de:bvb:20-opus-193707
10.25972/OPUS-19370
X 129054
Deutsches Urheberrecht
Valerie Indra Katharina Paprocki
deu
swd
Sandwich-Verbindungen
deu
swd
Metallierung
deu
swd
Diborabenzolderivate
deu
swd
Thorium
deu
swd
Uran
deu
uncontrolled
Sandwich Komplexe
deu
uncontrolled
Diborabenzol
Anorganische Chemie
open_access
Institut für Anorganische Chemie
Universität Würzburg
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/19370/thesis_Paprocki_Valerie_online.pdf
21559
2020
eng
10866-10873
15
59
article
1
2020-11-03
--
--
2,2′-Bipyridyl as a Redox-Active Borylene Abstraction Agent
2,2′-Bipyridyl is shown to spontaneously abstract a borylene fragment (R–B:) from various hypovalent boron compounds. This process is a redox reaction in which the bipyridine is reduced and becomes a dianionic substituent bound to boron through its two nitrogen atoms. Various transition metal–borylene complexes and diboranes, as a well as a diborene, take part in this reaction. In the latter case, our results show an intriguing example of the homolytic cleavage of a B═B double bond.
Inorganic Chemistry
10.1021/acs.inorgchem.0c01383
urn:nbn:de:bvb:20-opus-215595
This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Inorganic Chemistry, copyright © American Chemical Society after peer review. To access the final edited and published work see https://doi.org/10.1021/acs.inorgchem.0c01383.
publish
669054
Inorganic Chemistry 2020, 59, 15, 10866–10873. https://doi.org/10.1021/acs.inorgchem.0c01383
false
true
Deutsches Urheberrecht
Siyuan Liu
Marc-André Légaré
Jens Seufert
Dominic Prieschl
Anna Rempel
Lukas Englert
Theresa Dellermann
Valerie Paprocki
Andreas Stoy
Holger Braunschweig
eng
uncontrolled
Borylene
eng
uncontrolled
Heterocycles
eng
uncontrolled
Boron
eng
uncontrolled
Main-group chemistry
Anorganische Chemie
open_access
Institut für Anorganische Chemie
OpenAIRE
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/21559/Bipy.pdf
31222
2023
eng
11
29
article
1
--
--
--
Aromatic 1,2‐Azaborinin‐1‐yls as Electron‐Withdrawing Anionic Nitrogen Ligands for Main Group Elements
The 2‐aryl‐3,4,5,6‐tetraphenyl‐1,2‐azaborinines 1‐EMe\(_{3}\) and 2‐EMe\(_{3}\) (E=Si, Sn; aryl=Ph (1), Mes (=2,4,6‐trimethylphenyl, 2)) were synthesized by ring‐expansion of borole precursors with N\(_{3}\)EMe\(_{3}\)‐derived nitrenes. Desilylative hydrolysis of 1‐ and 2‐SiMe\(_{3}\) yielded the corresponding N‐protonated azaborinines, which were deprotonated with nBuLi or MN(SiMe\(_{3}\))\(_{2}\) (M=Na, K) to the corresponding group 1 salts, 1‐M and 2‐M. While the lithium salts crystallized as monomeric Lewis base adducts, the potassium salts formed coordination polymers or oligomers via intramolecular K⋅⋅⋅aryl π interactions. The reaction of 1‐M or 2‐M with CO\(_{2}\) yielded N‐carboxylate salts, which were derivatized by salt metathesis to methyl and silyl esters. Salt metathesis of 1‐M or 2‐M with methyl triflate, [Cp*BeCl] (Cp*=C\(_{5}\)Me\(_{5}\)), BBr\(_{2}\)Ar (Ar=Ph, Mes, 2‐thienyl), ECl\(_{3}\) (E=B, Al, Ga) and PX\(_{3}\) (X=Cl, Br) afforded the respective group 2, 13 and 15 1,2‐azaborinin‐2‐yl complexes. Salt metathesis of 1‐K with BBr\(_{3}\) resulted not only in N‐borylation but also Ph‐Br exchange between the endocyclic and exocyclic boron atoms. Solution \(^{11}\)B NMR data suggest that the 1,2‐azaborinin‐2‐yl ligand is similarly electron‐withdrawing to a bromide. In the solid state the endocyclic bond length alternation and the twisting of the C\(_{4}\)BN ring increase with the sterics of the substituents at the boron and nitrogen atoms, respectively. Regression analyses revealed that the downfield shift of the endocyclic \(^{11}\)B NMR resonances is linearly correlated to both the degree of twisting of the C\(_{4}\)BN ring and the tilt angle of the N‐substituent. Calculations indicate that the 1,2‐azaborinin‐1‐yl ligand has no sizeable π‐donor ability and that the aromaticity of the ring can be subtly tuned by the electronics of the N‐substituent.
Chemistry – A European Journal
10.1002/chem.202203345
urn:nbn:de:bvb:20-opus-312222
2023-04-19T18:39:09+00:00
sword
swordwue
attachment; filename=deposit.zip
67a4603e18480c1ed2234a91a74c8126
Chemistry – A European Journal 2023, 29(11):e202203345. DOI: 10.1002/chem.202203345
false
true
CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International
Felix Lindl
Anna Lamprecht
Merle Arrowsmith
Eugen Khitro
Anna Rempel
Maximilian Dietz
Tim Wellnitz
Guillaume Bélanger‐Chabot
Andreas Stoy
Valerie Paprocki
Dominik Prieschl
Carsten Lenczyk
Jacqueline Ramler
Crispin Lichtenberg
Holger Braunschweig
eng
uncontrolled
1,2-azaborinine
eng
uncontrolled
aromaticity
eng
uncontrolled
crystallographic analyses
eng
uncontrolled
N-functionalization
eng
uncontrolled
salt metathesis
Chemie und zugeordnete Wissenschaften
open_access
Institut für Anorganische Chemie
Import
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/31222/Lindl_Chemistry.pdf
21818
2020
deu
13209
13216
31
132
article
1
--
--
--
Ein neutrales 1,4‐Diborabenzol als \(\pi\)‐Ligand in Actinoidkomplexen
Die \(\pi\)-Koordination von Aren- und anionischen Heteroarenliganden ist ein allgegenwärtiges Strukturmotiv in der metallorganischen Chemie der d- und f-Block-Elemente. Im Gegensatz dazu sind vergleichbare \(\pi\)-Wechselwirkungen neutraler Heteroarene, darunter auch solche neutraler, aromatischer Borheterocyclen, für den f-Block weit weniger verbreitet, was z. T. mit einer geringeren Effektivität der Metall-zu-Ligand-Rückbindung in Zusammenhang gebracht werden kann. Für die Actinoide sind π-Komplexe mit neutralen Heteroarenliganden sogar gänzlich unbekannt. Durch Ausnutzung der außergewöhnlichen \(\pi\)-Donorstärke eines 1,4-Diborabenzols ist es uns nun gelungen, eine Reihe stabiler π-Halbsandwichkomplexe des Thoriums(IV) und des Urans(IV) über einen erstaunlich einfachen Zugang zu generieren: Umsetzung eines 1,4-Diborabenzols mit ThCl\(_{4}\)(dme)\(_{2}\) bzw. UCl\(_{4}\) in Gegenwart einer Lewis-Base. Hierdurch konnten die ersten Beispiele für Actinoidkomplexe mit einem neutralen Borheterocyclus als Sandwich-artigem Liganden erhalten werden. Laut experimentellen und theoretischen Studien ist die starke Actinoid-Heteroaren-Wechselwirkung in diesen Molekülen im Wesentlichen von elektrostatischer Natur. Der kovalente Hauptbeitrag wird hingegen von der Ligand-zu-Metall-\(\pi\)-Wechselwirkung geleistet, während \(\pi\)/δ-Rückbindungsanteile kaum eine Rolle spielen.
Angewandte Chemie
10.1002/ange.202004501
urn:nbn:de:bvb:20-opus-218181
2020-12-07T10:34:58+00:00
sword
swordwue
attachment; filename=deposit.zip
3e49211af4e5da413ae4c55e32dc7a4d
Angewandte Chemie 2020, 132(31):13209-13216. DOI: 10.1002/ange.202004501
false
true
CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International
Valerie Paprocki
Peter Hrobárik
Katie L. M. Harriman
Martin S. Luff
Thomas Kupfer
Martin Kaupp
Muralee Murugesu
Holger Braunschweig
deu
uncontrolled
Actinoide
deu
uncontrolled
Bindungsverhältnisse
deu
uncontrolled
Bor
deu
uncontrolled
Heterocyclen
deu
uncontrolled
\(\pi\)-Komplexe
Chemie und zugeordnete Wissenschaften
open_access
Institut für Anorganische Chemie
Import
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/21818/ANGE_ANGE202004501.pdf
25688
2021
eng
11226–11233
43
27
article
1
2022-02-14
--
--
Rethinking Borole Cycloaddition Reactivity
Boroles are attracting broad interest for their myriad and diverse applications, including in synthesis, small molecule activation and functional materials. Their properties and reactivity are closely linked to the cyclic conjugated diene system, which has been shown to participate in cycloaddition reactions, such as the Diels-Alder reaction with alkynes. The reaction steps leading to boranorbornadienes, borepins and tricyclic boracyclohexenes from the thermal reaction of boroles with alkynes are seemingly well understood as judged from the literature. Herein, we question the long-established mechanistic picture of pericyclic rearrangements by demonstrating that seven-membered borepins (i. e., heptaphenylborepin and two derivatives substituted with a thienyl and chloride substituent on boron) exist in a dynamic equilibrium with the corresponding bicyclic boranorbornadienes, the direct Diels-Alder products, but are not isolable products from the reactions. Heating gradually converts the isomeric mixtures into fluorescent tricyclic boracyclohexenes, the most stable isomers in the series. Results from mechanistic DFT calculations reveal that the tricyclic compounds derive from the boranorbornadienes and not the borepins, which were previously believed to be intermediates in purely pericyclic processes.
Chemistry—A European Journal
10.1002/chem.202101290
urn:nbn:de:bvb:20-opus-256888
publish
Chemistry—A European Journal 2021, 27(43):11226–11233. DOI: 10.1002/chem.202101290
false
true
CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International
Felix Lindl
Xueying Guo
Ivo Krummenacher
Florian Rauch
Anna Rempel
Valerie Paprocki
Theresa Dellermann
Tom E. Stennett
Anna Lamprecht
Tobias Brückner
Krzysztof Radacki
Guillaume Bélanger-Chabot
Todd B. Marder
Zhenyang Lin
Holger Braunschweig
eng
uncontrolled
pericyclic reaction
eng
uncontrolled
Boron
eng
uncontrolled
computational chemistry
eng
uncontrolled
isomer
eng
uncontrolled
isomerization
Anorganische Chemie
open_access
Institut für Anorganische Chemie
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/25688/Lindl_Chemistry.pdf