TY  - INPR
A1  - Braunschweig, Holger
A1  - Brückner, Tobias
A1  - Deißenberger, Andrea
A1  - Dewhurst, Rian
A1  - Gackstatter, Annika
A1  - Gärtner, Annalena
A1  - Hofmann, Alexander
A1  - Kupfer, Thomas
A1  - Prieschl, Dominic
A1  - Thiess, Torsten
A1  - Wang, Sunewang Rixin
T1  - Reaction of Dihalodiboranes(4) with N-Heterocyclic Silylenes: Facile Construction of 1-Aryl-2-Silyl-1,2-Diboraindanes
T2  - Chemistry, A European Journal
N2  - Dihalodiboranes(4) react with an N-heterocyclic silylene (NHSi) to generate NHSi-adducts of 1-aryl-2-silyl-1,2-diboraindanes as confirmed by X-ray crystallography, featuring the functionalization of both B–X (X = halogen) bonds and a C–H bond under mild conditions. Coordination of a third NHSi to the proposed 1,1-diaryl- 2,2-disilyldiborane(4) intermediates, generated by a two-fold B–X insertion, may be crucial for the C–H borylation that leads to the final products. Notably, our results demonstrate the first C–H borylation with a strong B–F bond activated by silylene insertion.
KW  - diborane
KW  - boron
KW  - silylenes
KW  - CH activation
KW  - bond activation
KW  - diboraindanes
KW  - diboranes
KW  - synthetic methods
KW  - borylation
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-153068
N1  - This is the pre-peer reviewed version of the following article: H. Braunschweig, T. Brückner, A. Deißenberger, R. D. Dewhurst, A. Gackstatter, A. Gärtner, A. Hofmann, T. Kupfer, D. Prieschl, T. Thiess, S. R. Wang, Reaction of Dihalodiboranes(4) with a N-Heterocyclic Silylene: Facile Construction of 1-Aryl-2-Silyl-1,2-Diboraindanes, Chem. Eur. J. 2017, 23, 9491., which has been published in final form at dx.doi.org/10.1002/chem.201702377. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving
ER  - 
TY  - JOUR
A1  - Witte, Robert
A1  - Arrowsmith, Merle
A1  - Lamprecht, Anna
A1  - Schorr, Fabian
A1  - Krummenacher, Ivo
A1  - Braunschweig, Holger
T1  - C−C and C−N Bond Activation, Lewis‐Base Coordination and One‐ and Two‐Electron Oxidation at a Linear Aminoborylene
JF  - Chemistry – A European Journal
N2  - A cyclic alkyl(amino)carbene (CAAC)‐stabilized dicoordinate aminoborylene is synthesized by the twofold reduction of a [(CAAC)BCl\(_{2}\)(TMP)] (TMP=2,6‐tetramethylpiperidyl) precursor. NMR‐spectroscopic, X‐ray crystallographic and computational analyses confirm the cumulenic nature of the central C=B=N moiety. Irradiation of [(CAAC)B(TMP)] (2) resulted in an intramolecular C−C bond activation, leading to a doubly‐fused C\(_{10}\)BN heterocycle, while the reaction with acetonitrile resulted in an aryl migration from the CAAC to the acetonitrile nitrogen atom, concomitant with tautomerization of the latter to a boron‐bound allylamino ligand. One‐electron oxidation of 2 with CuX (X=Cl, Br) afforded the corresponding amino(halo)boryl radicals, which were characterized by EPR spectroscopy and DFT calculations. Placing 2 under an atmosphere of CO afforded the tricoordinate (CAAC,CO)‐stabilized aminoborylene. Finally, the twofold oxidation of 2 with chalcogens led, in the case of N\(_{2}\)O and sulfur, to the splitting of the B−C\(_{CAAC}\) bond and formation of the 2,4‐diamino‐1,3,2,4‐dichalcogenadiboretanes and CAAC‐chalcogen adducts, whereas with selenium a monomeric boraselenone was isolated, which showed some degree of B−Se multiple bonding.
KW  - bond activation
KW  - boraselenone
KW  - dicoordinate borylene
KW  - one-electron oxidation
KW  - push-pull stabilization
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312491
VL  - 29
IS  - 16
ER  - 
TY  - INPR
A1  - Böhnke, Julian
A1  - Arrowsmith, Merle
A1  - Braunschweig, Holger
T1  - Activation of a Zerovalent Diboron Compound by Desymmetrization
T2  - Journal of the American Chemical Society
N2  - The desymmetrization of the cyclic (alkyl)(amino)carbene-supported diboracumulene, B\(_2\)(cAAC\(^{Me}\))\(_2\) (cAAC\(^{Me}\) = 1- (2,6-diisopropylphenyl)-3,3,5,5-tetramethylpyrrolidin-2-ylidene) by mono-adduct formation with IMe\(^{Me}\) (1,3-dimethylimidazol-2-ylidene) yields the zerovalent sp-sp\(^2\) diboron compound B\(_2\)(cAAC\(^{Me}\))\(_2\)(IMe\(^{Me}\)), which provides a versatile platform for the synthesis of novel symmetrical and unsymmetrical zerovalent sp\(^2\)-sp\(^2\) diboron compounds by adduct formation with IMe\(^{Me}\) and CO, respectively. Furthermore, B\(_2\)(cAAC\(^{Me}\))\(_2\)(IMe\(^{Me}\)) displays enhanced reactivity compared to its symmetrical precursor, undergoing spontaneous intramolecular C-H activation and facile twofold hydrogenation, the latter resulting in B-B bond cleavage and the formation of the mixed-base parent borylene, (cAAC\(^{Me}\))(IMe\(^{Me}\))BH.
KW  - diboryne
KW  - boron
KW  - carbenes
KW  - low-valent main group chemistry
KW  - erovalent diboron compounds
KW  - desymmetrization
KW  - bond activation
KW  - hydrogenation
KW  - borylene
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167983
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.8b06930
(Julian Böhnke, Merle Arrowsmith, and Holger Braunschweig: Reactivity Enhancement of a Zerovalent Diboron Compound by Desymmetrization, Journal of the American Chemical Society 2018, 140, (32), 10368-10373. DOI: 10.1021/jacs.8b06930)
ER  -