TY  - INPR
A1  - Hermann, Alexander
A1  - Arrowsmith, Merle
A1  - Trujillo-Gonzalez, Daniel
A1  - Jiménez-Halla, J. Oscar C.
A1  - Vargas, Alfredo
A1  - Braunschweig, Holger
T1  - Trapping of a Borirane Intermediate in the Reductive Coupling of an Arylborane to a Diborene
T2  - Journal of the American Chemical Society
N2  - The reductive coupling of an NHC-stabilized aryldibromoborane yields a mixture of trans- and cis-diborenes in which the aryl groups are coplanar with the diborene core. Under dilute reduction conditions two diastereomers of a borirane-borane intermediate are isolated, which upon further reduction give rise to the aforementioned diborene mixture. DFT calculations suggest a mechanism proceeding via nucleophilic attack of a dicoordinate borylene intermediate on the aryl ring and subsequent intramolecular B-B bond formation.
KW  - boron
KW  - reactive intermediates
KW  - reductive coupling
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203140
N1  - This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Journal of the American Chemical Society, copyright © American Chemical Society after peer review. To access the final edited and published work see https://doi.org/10.1021/jacs.0c02306
ER  - 
TY  - INPR
A1  - Schmidt, Uwe
A1  - Fantuzzi, Felipe
A1  - Arrowsmith, Merle
A1  - Hermann, Alexander
A1  - Prieschl, Dominic
A1  - Rempel, Anna
A1  - Engels, Bernd
A1  - Braunschweig, Holger
T1  - Tuneable reduction of cymantrenylboranes to diborenes or borylene-derived boratafulvenes
T2  - Chemical Communications
N2  - Whereas the reduction of N-heterocyclic carbene (NHC)-stabilised cymantrenyldibromoboranes, (NHC)BBr\(_2\)Cym, in benzene results in formation of the corresponding diborenes (NHC)\(_2\)B\(_2\)Cym\(_2\), a change of solvent to THF yields a borylene of the form (NHC)\(_2\)BCym, stabilised through its boratafulvene resonance form.
KW  - Borylene
KW  - Diborene
KW  - Boranes
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-222149
ER  - 
TY  - JOUR
A1  - Schmidt, Uwe
A1  - Werner, Luis
A1  - Arrowsmith, Merle
A1  - Deissenberger, Andrea
A1  - Hermann, Alexander
A1  - Hofmann, Alexander
A1  - Ullrich, Stefan
A1  - Mattock, James D.
A1  - Vargas, Alfredo
A1  - Braunschweig, Holger
T1  - Trans‐selektive Dihydroborierung eines cis‐Diborens durch Insertion: Synthese eines linearen sp\(^3\)‐sp\(^2\)‐sp\(^3\)‐Triborans und anschließende Kationisierung
JF  - Angewandte Chemie
N2  - Die Reaktion zwischen Aryl‐ und Amino(dihydro)boranen und Dibora[2]ferrocenophan 1 führt zur Bildung von 1,3‐trans‐Dihydrotriboranen durch formale Hydrierung und Insertion eines Borylens in die B=B Doppelbindung. Die Aryltriboran‐Derivate unterliegen einer reversiblen Photoisomerisierung zugunsten eines cis‐1,2‐μ‐H‐3‐Hydrotriborans, während eine Hydridabstraktion zu kationischen Triboranen führt, welche die ersten doppelt basenstabilisierten B\(_3\)H\(_4\)\(^+\)‐Analoga darstellen.
KW  - Diboren
KW  - Hydroborierung
KW  - Kation
KW  - Photoisomerisierung
KW  - Triboran
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219713
VL  - 132
IS  - 1
ER  - 
TY  - JOUR
A1  - Schmidt, Uwe
A1  - Werner, Luis
A1  - Arrowsmith, Merle
A1  - Deissenberger, Andrea
A1  - Hermann, Alexander
A1  - Hofmann, Alexander
A1  - Ullrich, Stefan
A1  - Mattock, James D.
A1  - Vargas, Alfredo
A1  - Braunschweig, Holger
T1  - trans-Selective Insertional Dihydroboration of a cis-Diborene: Synthesis of Linear sp\(^3\)-sp\(^2\)-sp\(^3\)-Triboranes and Subsequent Cationization
JF  - Angewandte Chemie International Edition
N2  - The reaction of aryl‐ and amino(dihydro)boranes with dibora[2]ferrocenophane 1 leads to the formation 1,3‐trans ‐dihydrotriboranes by formal hydrogenation and insertion of a borylene unit into the B=B bond. The aryltriborane derivatives undergo reversible photoisomerization to the cis ‐1,2‐μ‐H‐3‐hydrotriboranes, while hydride abstraction affords cationic triboranes, which represent the first doubly base‐stabilized B3H4\(^+\) analogues.
KW  - cations
KW  - hydroboration
KW  - photoisomerization
KW  - triboranes
KW  - diborenes
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-208090
VL  - 59
IS  - 1
ER  - 
TY  - JOUR
A1  - Hermann, Alexander
A1  - Fantuzzi, Felipe
A1  - Arrowsmith, Merle
A1  - Zorn, Theresa
A1  - Krummenacher, Ivo
A1  - Ritschel, Benedikt
A1  - Radacki, Krzysztof
A1  - Engels, Bernd
A1  - Braunschweig, Holger
T1  - Oxidation, Coordination, and Nickel-Mediated Deconstruction of a Highly Electron-Rich Diboron Analogue of 1,3,5-Hexatriene
JF  - Angewandte Chemie, International Edition
N2  - The reductive coupling of an N-heterocyclic carbene (NHC) stabilized (dibromo)vinylborane yields a 1,2-divinyl- diborene, which, although isoelectronic to a 1,3,5-triene, displays no extended p conjugation because of twisting of the C\(_2\)B\(_2\)C\(_2\) chain. While this divinyldiborene coordinates to copper(I) and platinum(0) in an η\(^2\)-B\(_2\) and η\(^4\)-C\(_2\)B\(_2\) fashion, respectively, it undergoes a complex rearrangement to an η\(^4\)-1,3-diborete upon complexation with nickel(0).
KW  - boron
KW  - diborenes
KW  - carbenes
KW  - conjugation
KW  - density-functional calculations
KW  - rearrangements
KW  - structure elucidation
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-240652
VL  - 59
IS  - 36
ER  -