TY  - INPR
A1  - Brückner, Tobias
A1  - Stennett, Tom E.
A1  - Heß, Merlin
A1  - Braunschweig, Holger
T1  - Single and Double Hydroboration of B-B Triple Bonds and Conver- gent Routes to a Cationic Tetraborane
T2  - Journal of the American Chemical Society
N2  - A compound with a boron-boron triple bond is shown to undergo stepwise hydroboration reactions with catecholborane to yield an unsymmetrical hydro(boryl)diborene and a 2,3-dihydrotetraborane. Abstraction of H– from the latter compound produces an unusual cationic, planar tetraborane with a hydrogen atom bridging the central B2 moiety. Spectroscopic and crystallographic data and DFT calculations support a ‘protonated diborene’ structure for this compound, which can also be accessed via direct protonation of the corresponding diborene.
KW  - boron
KW  - multiple bonding
KW  - hydroboration
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-188632
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.9b07991.
ER  - 
TY  - INPR
A1  - Brückner, Tobias
A1  - Arrowsmith, Merle
A1  - Heß, Merlin
A1  - Hammond, Kai
A1  - Müller, Marcel
A1  - Braunschweig, Holger
T1  - Synthesis of fused B,N-heterocycles by alkyne cleavage, NHC ring-expansion and C-H activation at a diboryne
T2  - Chemical Communications
N2  - The addition of alkynes to a staturated N-heterocyclic carbene (NHC)-supported diboryne results in spontaneous cycloaddition, with complete B≡B and C≡C triple bond cleavage, NHC ring- expansion and activation of a variety of C-H bonds, leading to the formation of complex mixtures of fused B,N-heterocycles.
KW  - heterocycles
KW  - alkynes
KW  - boron
KW  - carbenes
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-184899
N1  - This is the pre-peer reviewed version of the following article: Chem. Commun., 2019,55, 6700-6703, which has been published in final form at doi:10.1039/C9CC02657F
ER  - 
TY  - INPR
A1  - Böhnke, Julian
A1  - Dellermann, Theresa
A1  - Celik, Mehmet Ali
A1  - Krummenacher, Ivo
A1  - Dewhurst, Rian D.
A1  - Demeshko, Serhiy
A1  - Ewing, William C.
A1  - Hammond, Kai
A1  - Heß, Merlin
A1  - Bill, Eckhard
A1  - Welz, Eileen
A1  - Röhr, Merle I. S.
A1  - Mitric, Roland
A1  - Engels, Bernd
A1  - Meyer, Franc
A1  - Braunschweig, Holger
T1  - Isolation of diradical products of twisted double bonds
T2  - Nature Communications
N2  - Molecules containing multiple bonds between atoms—most often in the form of olefins—are ubiquitous in nature, commerce, and science, and as such have a huge impact on everyday life. Given their prominence, over the last few decades, frequent attempts have been made to perturb the structure and reactivity of multiply-bound species through bending and twisting. However, only modest success has been achieved in the quest to completely twist double bonds in order to homolytically cleave the associated π bond. Here, we present the isolation of double-bond-containing species based on boron, as well as their fully twisted diradical congeners, by the incorporation of attached groups with different electronic properties. The compounds comprise a structurally authenticated set of diamagnetic multiply-bound and diradical singly-bound congeners of the same class of compound.
KW  - diradicals
KW  - diborenes
KW  - carbenes
KW  - boron
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-160248
N1  - Submitted version of Julian Böhnke, Theresa Dellermann, Mehmet Ali Celik, Ivo Krummenacher, Rian D. Dewhurst, Serhiy Demeshko, William C. Ewing, Kai Hammond, Merlin Heß, Eckhard Bill, Eileen Welz, Merle I. S. Röhr, Roland Mitrić, Bernd Engels, Franc Meyer & Holger Braunschweig: Isolation of diborenes and their 90°-twisted diradical congeners. Nature Communications. Volume 9, Article number: 1197 (2018) doi:10.1038/s41467-018-02998-3
ER  -