TY  - INPR
A1  - Braunschweig, Holger
A1  - Krummenacher, Ivo
A1  - Lichtenberg, Crispin
A1  - Mattock, James
A1  - Schäfer, Marius
A1  - Schmidt, Uwe
A1  - Schneider, Christoph
A1  - Steffenhagen, Thomas
A1  - Ullrich, Stefan
A1  - Vargas, Alfredo
T1  - Dibora[2]ferrocenophane: A Carbene-Stabilized Diborene in a Strained cis-Configuration
T2  - Angewandte Chemie, International Edition
N2  - Unsaturated bridges that link the two cyclopentadienyl ligands together in strained ansa metallocenes are rare and limited to carbon-carbon double bonds. The synthesis and isolation of a strained ferrocenophane containing an unsaturated two-boron bridge, isoelectronic with a C=C double bond, was achieved by reduction of a carbene-stabilized 1,1’-bis(dihaloboryl)ferrocene. A combination of spectroscopic and electrochemical measurements as well as density functional theory (DFT) calculations was used to assess the influence of the unprecedented strained cis configuration on the optical and electrochemical properties of the carbene-stabilized diborene unit. Initial reactivity studies show that the dibora[2]ferrocenophane is prone to boron-boron double bond cleavage reactions.
KW  - Boron
KW  - Metallocenes
KW  - Metallocene
KW  - Bor
KW  - Diborane
KW  - density functional calculations
KW  - strained molecules
KW  - diborenes
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-141981
N1  - This is the pre-peer reviewed version of the following article: Angewandte Chemie, International Edition, Volume 56, Issue 3, 889–892, which has been published in final form at doi:10.1002/anie.201609601. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
ER  - 
TY  - JOUR
A1  - Braunschweig, Holger
A1  - Kramer, T.
T1  - Crystal structure of μ-1κC:2(\(η^2\))-carbonyl-carbonyl-1κC-chlorido-2κCl-μ-chloridoborylene-1:2\(κ^2\) B:B-[1(\(η^5\))-pentamethylcyclopentadienyl](tricyclohexylphosphane-2κP)iron(II)platinum(II) benzene monosolvate
N2  - In the mol­ecular structure of the dinuclear title compound \([η^5-(C_5(CH_3)_5)(CO)Fe{(μ-BCl)(μ-CO)}PtCl(P(C_6H_{11})_3)]·C_6H_6\), the two metal atoms, iron(II) and platinum(II), are bridged by one carbonyl (μ-CO) and one chlorido­borylene ligand (μ-BCl). The \(Pt^{II}\) atom is additionally bound to a chloride ligand situated trans to the bridging borylene, and a tri­cyclo­hexyl­phosphane ligand \((PCy_3)\) trans to the carbonyl ligand, forming a distorted square-planar structural motif at the \(Pt^{II}\) atom. The \(Fe_{II}\) atom is bound to a penta­methyl­cyclo­penta­dienyl ligand \([η^5-C_5(CH_3)_5]\) and one carbonyl ligand (CO), forming a piano-stool structure. Additionally, one benzene solvent mol­ecule is incorporated into the crystal structure, positioned staggered relative to the penta­methyl­cyclo­penta­dienyl ligand at the \(Fe^{II}\) atom, with a centroid–centroid separation of 3.630 (2) Å.
KW  - platinum
KW  - oxidative addition
KW  - borylene
KW  - heterodinuclear compound
KW  - crystal structure
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120120
VL  - 70
IS  - 11
ER  - 
TY  - JOUR
A1  - Braunschweig, Holger
A1  - Ewing, William C.
A1  - Ghosh, Sundargopal
A1  - Kramer, Thomas
A1  - Mattock, James D.
A1  - Östreicher, Sebastian
A1  - Vargas, Alfredo
A1  - Werner, Christine
T1  - Trimetallaborides as starting points for the syntheses of large metal-rich molecular borides and clusters
JF  - Chemical Science
N2  - Treatment of an anionic dimanganaborylene complex ([{Cp(CO)\(_2\)Mn}\(_2\)B]\(^-\)) with coinage metal cations stabilized by a very weakly coordinating Lewis base (SMe\(_2\)) led to the coordination of the incoming metal and subsequent displacement of dimethylsulfide in the formation of hexametalladiborides featuring planar four-membered M\(_2\)B\(_2\) cores (M = Cu, Au) comparable to transition metal clusters constructed around four-membered rings composed solely of coinage metals. The analogies between compounds consisting of B\(_2\)M\(_2\) units and M\(_4\) (M = Cu, Au) units speak to the often overlooked metalloid nature of boron. Treatment of one of these compounds (M = Cu) with a Lewis-basic metal fragment (Pt(PCy\(_3\))\(_2\)) led to the formation of a tetrametallaboride featuring two manganese, one copper and one platinum atom, all bound to boron in a geometry not yet seen for this kind of compound. Computational examination suggests that this geometry is the result of d\(^{10}\)-d\(^{10}\) dispersion interactions between the copper and platinum fragments.
KW  - anionic dimetalloborylene complexes
KW  - trimetallaborides
KW  - tetrametallaborides
KW  - Boron
KW  - metallaboranes
KW  - crystal structure
KW  - metal borylene complexes
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-191511
VL  - 7
IS  - 1
ER  - 
TY  - JOUR
A1  - Braunschweig, Holger
A1  - Dewhurst, Rian D.
A1  - Schwab, Katrin
A1  - Wagner, Katharina
T1  - {N ',N ''-Bis[2,6-bis(1-methylethyl)phenyl]-N,N-dimethylguanidinato-kappa N-2 ',N ''}dibromidoborane
N2  - In the molecular structure of the title compound, C27H40N3BBr2, the B atom is connected to two bromide substituents and a guanidinate scaffold, forming a four– membered ring. An aryl group is connected to each N atom in the ring that contains two isopropyl groups in positions 2 and 6.
KW  - Anorganische Chemie
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-67622
ER  - 
TY  - JOUR
A1  - Braunschweig, Holger
A1  - Damme, Alexander
T1  - 1,2-Bis(dimethylamino)-1,2-bis(2,4,6-triisopropylphenyl)diborane(4)
N2  - In the molecular structure of the title compound, C34H58B2N2, each B atom of the diborane(4) is connected to one dimethylamino group and one Tip ligand (Tip = 2,4,6-triisopropylphenyl). These findings indicate that the increased steric demand of the Tip groups exerts influence solely on the B—B separation but not on the overall geometry of the title compound.
KW  - Anorganische Chemie
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-67639
ER  - 
TY  - JOUR
A1  - Braunschweig, Holger
A1  - Constantinidis, Philipp
A1  - Dellermann, Theresa
A1  - Ewing, William
A1  - Fischer, Ingo
A1  - Hess, Merlin
A1  - Knight, Fergus
A1  - Rempel, Anna
A1  - Schneider, Christoph
A1  - Ullrich, Stefan
A1  - Vargas, Alfredo
A1  - Woolins, Derek
T1  - Highly Strained Heterocycles Constructed from Boron–Boron Multiple Bonds and Heavy Chalcogens
JF  - Angewandte Chemie, International Edition
N2  - The reactions of a diborene with elemental selenium or tellurium are shown to afford a diboraselenirane or diboratellurirane, respectively. These reactions are reminiscent of the sequestration of subvalent oxygen and nitrogen in the formation of oxiranes and aziridines; however, such reactivity is not known between alkenes and the heavy chalcogens. Although carbon is too electronegative to affect the reduction of elements with lower relative electronegativity, the highly reducing nature of the B B double bond enables reactions with Se0 and Te0. The capacity of multiple bonds between boron atoms to donate electron density is highlighted in reactions where diborynes behave as nucleophiles, attacking one of the two Te atoms of diaryltellurides, forming salts consisting of diboratellurenium cations and aryltelluride anions.
KW  - Boron
KW  - Heterocycles
KW  - Multiple bonds
KW  - Selenium
KW  - Tellurium
KW  - Bor
KW  - Heterocyclische Verbindungen
KW  - Selen
KW  - Tellur
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-138237
N1  - This is the peer reviewed version of the following article: Angew. Chem. Int. Ed. 2016, 55, 5606–5609, which has been published in final form at 10.1002/anie.201601691. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
N1  - Accepted Version
VL  - 55
IS  - 18
SP  - 5606
EP  - 5609
ER  - 
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  - Braunschweig, Holger
A1  - Arnold, Thomas
A1  - Gruss, Katrin
T1  - cyclo-Tri-mu-oxido-tris{[(eta 5,eta 5)-1,2-bis(cyclopentadienyl)-1,1,2,2-tetramethyldisilane]zirconium(IV)}: atrimeric disila-bridged oxidozirconocene
N2  - no abstract available
KW  - Chemie
KW  - single-crystal X-ray study
KW  - T = 174 K
KW  - R factor = 0.027
KW  - wR factor = 0.069
KW  - data-to-parameter ratio = 23.6.
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-74737
ER  - 
TY  - JOUR
A1  - Berger, Sarina M.
A1  - Rühe, Jessica
A1  - Schwarzmann, Johannes
A1  - Phillipps, Alexandra
A1  - Richard, Ann-Katrin
A1  - Ferger, Matthias
A1  - Krummenacher, Ivo
A1  - Tumir, Lidija-Marija
A1  - Ban, Željka
A1  - Crnolatac, Ivo
A1  - Majhen, Dragomira
A1  - Barišić, Ivan
A1  - Piantanida, Ivo
A1  - Schleier, Domenik
A1  - Griesbeck, Stefanie
A1  - Friedrich, Alexandra
A1  - Braunschweig, Holger
A1  - Marder, Todd B.
T1  - Bithiophene-Cored, mono-, bis-, and tris-(Trimethylammonium)-Substituted, bis-Triarylborane Chromophores: Effect of the Number and Position of Charges on Cell Imaging and DNA/RNA Sensing
JF  - Chemistry—A European Journal
N2  - The synthesis, photophysical, and electrochemical properties of selectively mono-, bis- and tris-dimethylamino- and trimethylammonium-substituted bis-triarylborane bithiophene chromophores are presented along with the water solubility and singlet oxygen sensitizing efficiency of the cationic compounds Cat\(^{1+}\), Cat\(^{2+}\), Cat(i)\(^{2+}\), and Cat\(^{3+}\). Comparison with the mono-triarylboranes reveals the large influence of the bridging unit on the properties of the bis-triarylboranes, especially those of the cationic compounds. Based on these preliminary investigations, the interactions of Cat\(^{1+}\), Cat\(^{2+}\), Cat(i)\(^{2+}\), and Cat\(^{3+}\) with DNA, RNA, and DNApore were investigated in buffered solutions. The same compounds were investigated for their ability to enter and localize within organelles of human lung carcinoma (A549) and normal lung (WI38) cells showing that not only the number of charges but also their distribution over the chromophore influences interactions and staining properties.
KW  - singlet oxygen
KW  - boron
KW  - bioimaging
KW  - luminescence
KW  - nucleic acid
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256963
VL  - 27
IS  - 56
ER  - 
TY  - JOUR
A1  - Bachmann, Jonas
A1  - Helbig, Andreas
A1  - Crumbach, Merian
A1  - Krummenacher, Ivo
A1  - Braunschweig, Holger
A1  - Helten, Holger
T1  - Fusion of Aza‐ and Oxadiborepins with Furans in a Reversible Ring‐Opening Process Furnishes Versatile Building Blocks for Extended π‐Conjugated Materials
JF  - Chemistry – A European Journal
N2  - A modular synthesis of both difurooxa‐ and difuroazadiborepins from a common precursor is demonstrated. Starting from 2,2′‐bifuran, after protection of the positions 5 and 5’ with bulky silyl groups, formation of the novel polycycles proceeds through opening of the furan rings to a dialkyne and subsequent re‐cyclization in the borylation step. The resulting bifuran‐fused diborepins show pronounced stability, highly planar tricyclic structures, and intense blue light emission. Deprotection and transformation into dibrominated building blocks that can be incorporated into π‐extended materials can be performed in one step. Detailed DFT calculations provide information about the aromaticity of the constituent rings of this polycycle.
KW  - aromaticity
KW  - boron
KW  - BN compounds
KW  - furan
KW  - polycycles
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-293926
VL  - 28
IS  - 63
ER  - 
TY  - INPR
A1  - Auerhammer, Dominic
A1  - Arrowsmith, Merle
A1  - Böhnke, Julian
A1  - Braunschweig, Holger
A1  - Dewhurst, Rian D.
A1  - Kupfer, Thomas
T1  - Brothers from Another Mother: a Borylene and its Dimer are Non-Interconvertible but Connected through Reactivity
T2  - Chemical Science
N2  - The self-stabilizing, tetrameric cyanoborylene [(cAAC)B(CN)]4 (I, cAAC = 1-(2,6-diisopropylphenyl)-3,3,5,5-tetramethylpyrrolidin-2-ylidene) and its diborene relative, [(cAAC)(CN)B=B(CN)(cAAC)] (II), both react with disulfides and diselenides to yield the corresponding cAAC-supported cyanoboron bis(chalcogenides). Furthermore, reactions of I or II with elemental sulfur and selenium in various stoichiometries provided access to a variety of cAAC- stabilized cyanoboron-chalcogen heterocycles, including a unique dithiaborirane, a diboraselenirane, 1,3-dichalcogena-2,4-diboretanes, 1,3,4-trichalcogena- 2,5-diborolanes and a rare six-membered 1,2,4,5-tetrathia-3,6-diborinane. Stepwise addition reactions and solution stability studies provided insights into the mechanism of these reactions and the subtle differences in reactivity observed between I and II.
KW  - borylenes
KW  - diborenes
KW  - boron
KW  - carbenes
KW  - chalcogens
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-157125
ER  - 
TY  - JOUR
A1  - Auerhammer, Dominic
A1  - Arrowsmith, Merle
A1  - Braunschweig, Holger
A1  - Dewhurst, Rian D.
A1  - Jiménez-Halla, J. Oscar C.
A1  - Kupfer, Thomas
T1  - Nucleophilic addition and substitution at coordinatively saturated boron by facile 1,2-hydrogen shuttling onto a carbene donor
JF  - Chemical Science
N2  - The reaction of [(cAAC\(^{Me}\))BH\(_{3}\)] (cAAC\(^{Me}\) = 1-(2,6-iPr\(_{2}\)C\(_{6}\)H\(_{3}\))-3,3,5,5-tetramethylpyrrolidin-2-ylidene) with a range of organolithium compounds led to the exclusive formation of the corresponding (dihydro)organoborates, Li\(^{+}\)[(cAAC\(^{Me}\)H)BH\(_{2}\)R]− (R = sp\(^{3}\)-, sp\(^{2}\)-, or sp-hybridised organic substituent), by migration of one boron-bound hydrogen atom to the adjacent carbene carbon of the cAAC ligand. A subsequent deprotonation/salt metathesis reaction with Me3SiCl or spontaneous LiH elimination yielded the neutral cAAC-supported mono(organo)boranes, [(cAAC\(^{Me}\)H)BH\(_{2}\)R]− (R]. Similarly the reaction of [cAAC\(^{Me}\))BH\(_{3}\)] with a neutral donor base L resulted in adduct formation by shuttling one boron-bound hydrogen to the cAAC ligand, to generate [(cAAC\(^{Me}\)H)BH\(_{2}\)L], either irreversibly (L = cAAC\(^{Me}\)) or reversibly (L = pyridine). Variable-temperature NMR data and DFT calculations on [(cAAC\(^{Me}\)H)BH\(_{2}\)(cAAC\(^{Me}\))] show that the hydrogen on the former carbene carbon atom exchanges rapidly with the boron-bound hydrides.
KW  - nucleophilic addition
KW  - nucleophilic substitution
KW  - boron-bound hydrogen
KW  - carbene donor
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170255
VL  - 8
IS  - 10
ER  - 
TY  - INPR
A1  - Auerhammer, Dominic
A1  - Arrowsmith, Merle
A1  - Bissinger, Philipp
A1  - Braunschweig, Holger
A1  - Dellermann, Theresa
A1  - Kupfer, Thomas
A1  - Lenczyk, Carsten
A1  - Roy, Dipak
A1  - Schäfer, Marius
A1  - Schneider, Christoph
T1  - Increasing the Reactivity of Diborenes: Derivatization of NHC- Supported Dithienyldiborenes with Electron-Donor Groups
T2  - Chemistry, A European Journal
N2  - A series of NHC-supported 1,2-dithienyldiborenes was synthesized from the corresponding (dihalo)thienylborane NHC precursors. NMR and UV-vis spectroscopic data, as well as X-ray crystallographic analyses, were used to assess the electronic and steric influences on the B=B double bond of various NHCs and electron-donating substituents on the thienyl ligands. Crystallographic data showed that the degree of coplanarity of the diborene core and thienyl groups is highly dependent on the sterics of the substituents. Furthermore, any increase in the electron- donating ability of the substituents resulted in the destabilization of the HOMO and greater instability of the resulting diborenes.
KW  - diborenes
KW  - N-heterocyclic carbenes
KW  - electron donors
KW  - structural analysis
KW  - spectroscopy
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-155419
N1  - This is the pre-peer reviewed version of the following article: Auerhammer, D., Arrowsmith, M., Bissinger, P., Braunschweig, H., Dellermann, T., Kupfer, T., Lenczyk, C., Roy, D. K., Schäfer, M. and Schneider, C. (2017), Increasing the Reactivity of Diborenes: Derivatization of NHC-Supported Dithienyldiborenes with Electron-Donor Groups. Chem. Eur. J.. doi:10.1002/chem.201704669, which has been published in final form at doi:10.1002/chem.201704669. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
ER  - 
TY  - INPR
A1  - Arrowsmith, Merle
A1  - Mattock, James D.
A1  - Böhnke, Julian
A1  - Krummenacher, Ivo
A1  - Vargas, Alfredo
A1  - Braunschweig, Holger
T1  - Direct access to a cAAC-supported dihydrodiborene and its dianion
T2  - Chemical Communications
N2  - The two-fold reduction of (cAAC)BHX\(_2\) (cAAC = 1-(2,6-diisopropylphenyl)-3,3,5,5-tetramethylpyrrolidin-2-ylidene; X = Cl, Br) provides a facile, high-yielding route to the dihydrodiborene (cAAC)\(_2\)B\(_2\)H\(_2\). The (chloro)hydroboryl anion reduction intermediate was successfully isolated using a crown ether. Overreduction of the diborene to its dianion [(cAAC)\(_2\)B\(_2\)H\(_2\)]\(^{2−}\) causes a decrease in the B–B bond order whereas the B–C bond orders increase.
KW  - carbenes
KW  - diborenes
KW  - boron
KW  - main-group chemistry
KW  - diborynes
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164276
N1  - This is the pre-peer reviewed version of the following article: Chemical Communications, 2018, 54, 4669-4672 which has been published at DOI: 10.1039/C8CC01580E
ER  - 
TY  - JOUR
A1  - Arrowsmith, Merle
A1  - Endres, Sara
A1  - Heinz, Myron
A1  - Nestler, Vincent
A1  - Holthausen, Max C.
A1  - Braunschweig, Holger
T1  - Probing the Boundaries between Lewis-Basic and Redox Behavior of a Parent Borylene
JF  - Chemistry—A European Journal
N2  - The parent borylene (CAAC)(Me\(_{3}\)P)BH, 1 (CAAC=cyclic alkyl(amino)carbene), acts both as a Lewis base and one-electron reducing agent towards group 13 trichlorides (ECl\(_{3}\), E=B, Al, Ga, In), yielding the adducts 1-ECl\(_{3}\) and increasing proportions of the radical cation [1]\(^{•+}\) for the heavier group 13 analogues. With boron trihalides (BX\(_{3}\), X=F, Cl, Br, I) 1 undergoes sequential adduct formation and halide abstraction reactions to yield borylboronium cations and shows an increasing tendency towards redox processes for the heavier halides. Calculations confirm that 1 acts as a strong Lewis base towards EX3 and show a marked increase in the B−E bond dissociation energies down both group 13 and the halide group.
KW  - redox processes
KW  - bond dissociation energies
KW  - borylene
KW  - group 13
KW  - Lewis adducts
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-257154
VL  - 27
IS  - 70
ER  - 
TY  - INPR
A1  - Arrowsmith, Merle
A1  - Dömling, Michael
A1  - Schmidt, Uwe
A1  - Werner, Luis
A1  - Castro, Abril C.
A1  - Jiménez-Halla, J. Oscar C.
A1  - Müssig, Jonas
A1  - Prieschl, Dominic
A1  - Braunschweig, Holger
T1  - Spontaneous trans‐Selective Transfer Hydrogenation of Apolar B=B Double Bonds
T2  - Angewandte Chemie, International Edition
N2  - The transfer hydrogenation of NHC-supported diborenes with dimethylamine borane proceeds with high selectivity for the trans-1,2-dihydrodiboranes(6). DFT calculations suggest a stepwise proton-first-hydride-second reaction mechanism via an intermediate μ-hydrodiboronium dimethylaminoborate ion pair.
KW  - transfer hydrogenation
KW  - diborene
KW  - amine borane dehydrocoupling
KW  - diboranes
KW  - DFT mechanism
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-184874
N1  - This is the pre-peer reviewed version of the following article: M. Dömling, M. Arrowsmith, U. Schmidt, L. Werner, A. C. Castro, J. O. C. Jiménez-Halla, R. Bertermann, J. Müssig, D. Prieschl, H. Braunschweig, Angew. Chem. Int. Ed. 2019, 58, 9782. doi:10.1002/anie.201902656, which has been published in final form at  https://doi.org/10.1002/anie.201902656. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.
ER  - 
TY  - INPR
A1  - Arrowsmith, Merle
A1  - Böhnke, Julian
A1  - Braunschweig, Holger
A1  - Deißenberger, Andrea
A1  - Dewhurst, Rian
A1  - Ewing, William
A1  - Hörl, Christian
A1  - Mies, Jan
A1  - Muessig, Jonas
T1  - Simple Solution-Phase Syntheses of Tetrahalodiboranes(4) and their Labile Dimethylsulfide Adducts
T2  - Chemical Communications
N2  - Convenient, solution-phase syntheses of tetrahalodiboranes(4) B\(_2\)F\(_4\), B\(_2\)Cl\(_4\) and B\(_2\)I\(_4\) are presented herein from common precursor B\(_2\)Br\(_4\). In addition, the dimethylsulfide adducts B\(_2\)Cl\(_4\)(SMe\(_2\))\(_2\) and B\(_2\)Br\(_4\)(SMe\(_2\))\(_2\) are conveniently prepared in one-step syntheses from the commercially-available starting material B\(_2\)(NMe\(_2\))\(_4\). The results provide simple access to the full range of tetrahalodiboranes(4) for the exploration of their untapped synthetic potential.
KW  - Boron
KW  - Diboranes
KW  - Tetrafluorodiborane
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149438
N1  - This is the pre-peer reviewed version of the following article: Chemical Communications, 2017,53, 8265-8267, which has been published in final form at doi:10.1039/C7CC03148C.
VL  - 53
ER  - 
TY  - JOUR
A1  - Arrowsmith, Merle
A1  - Böhnke, Julian
A1  - Braunschweig, Holger
A1  - Celik, Mehmet
A1  - Dellermann, Theresa
A1  - Hammond, Kai
T1  - Uncatalyzed Hydrogenation of First-Row Main Group Multiple Bonds
JF  - Chemistry, A European Journal
N2  - Room temperature hydrogenation of an SIDep-stabilized diboryne (SIDep = 1,3-bis(diethylphenyl)-4,5-dihydroimidazol-2-ylidene) and a CAAC-supported diboracumulene (CAAC = 1-(2,6- diisopropylphenyl)-3,3,5,5-tetramethylpyrrolidin-2-ylidene) provided the first selective route to the corresponding 1,2-dihydrodiborenes. DFT calculations showed an overall exothermic (ΔG = 19.4 kcal mol\(^{-1}\) two-step asynchronous H\(_2\) addition mechanism proceeding via a bridging hydride.
KW  - diborenes
KW  - carbenes
KW  - hydrogenation
KW  - main-group chemistry
KW  - reaction mechanism
KW  - Diborane
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-139364
N1  - This is the peer reviewed version of the following article: Chemistry, A European Journal, 2016, 22, 17169–17172, which has been published in final form at 10.1002/chem.201604094. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
VL  - 22
IS  - 48
SP  - 17169
EP  - 17172
ER  - 
TY  - INPR
A1  - Arrowsmith, Merle
A1  - Böhnke, Julian
A1  - Braunschweig, Holger
A1  - Celik, Mehmet
A1  - Claes, Christina
A1  - Ewing, William
A1  - Krummenacher, Ivo
A1  - Lubitz, Katharina
A1  - Schneider, Christoph
T1  - Neutral Diboron Analogues of Archetypal Aromatic Species by Spontaneous Cycloaddition
N2  - Among the numerous routes organic chemists have developed to synthesize benzene derivatives and heteroaro- matic compounds, transition-metal-catalyzed cycloaddition reactions are the most elegant. In contrast, cycloaddition reactions of heavier alkene and alkyne analogues, though limited in scope, proceed uncatalyzed. In this work we present the first spontaneous cycloaddition reactions of lighter alkene and alkyne analogues. Selective addition of unactivated alkynes to boron–boron multiple bonds under ambient con- ditions yielded diborocarbon equivalents of simple aromatic hydrocarbons, including the first neutral 6p-aromatic dibora- benzene compound, a 2 p-aromatic triplet biradical 1,3-dibor- ete, and a phosphine-stabilized 2 p-homoaromatic 1,3-dihydro- 1,3-diborete. DFT calculations suggest that all three com- pounds are aromatic and show frontier molecular orbitals matching those of the related aromatic hydrocarbons, C6H6 and C4H42+, and homoaromatic C4H5+.
KW  - Aromaticity
KW  - Biradicals
KW  - Boron
KW  - Cycloaddition
KW  - Multiple bonds
KW  - Diborane
KW  - Cycloaddition
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-142500
ER  - 
TY  - JOUR
A1  - Arrowsmith, Merle
A1  - Böhnke, Julian
A1  - Braunschweig, Holger
A1  - Celik, Mehmet
A1  - Claes, Christina
A1  - Ewing, William
A1  - Krummenacher, Ivo
A1  - Lubitz, Katharina
A1  - Schneider, Christoph
T1  - Neutral Diboron Analogues of Archetypal Aromatic Species by Spontaneous Cycloaddition
JF  - Angewandte Chemie, International Edition
N2  - Among the numerous routes organic chemists have developed to synthesize benzene derivatives and heteroaro- matic compounds, transition-metal-catalyzed cycloaddition reactions are the most elegant. In contrast, cycloaddition reactions of heavier alkene and alkyne analogues, though limited in scope, proceed uncatalyzed. In this work we present the first spontaneous cycloaddition reactions of lighter alkene and alkyne analogues. Selective addition of unactivated alkynes to boron–boron multiple bonds under ambient con- ditions yielded diborocarbon equivalents of simple aromatic hydrocarbons, including the first neutral 6 π-aromatic dibora- benzene compound, a 2  π-aromatic triplet biradical 1,3-dibor- ete, and a phosphine-stabilized 2  π-homoaromatic 1,3-dihydro- 1,3-diborete. DFT calculations suggest that all three com- pounds are aromatic and show frontier molecular orbitals matching those of the related aromatic hydrocarbons, C\(_6\)H\(_6\) and C\(_4\)H\(_4\)\(^{2+}\), and homoaromatic C\(_4\)H\(_5\)\(^+\).
KW  - Aromaticity
KW  - Biradicals
KW  - Boron
KW  - Cycloaddition
KW  - Multiple bonds
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-138226
N1  - This is the peer reviewed version of the following article: Angew. Chem. Int. Ed. 2016, 55, 11271–11275, which has been published in final form at 10.1002/anie.201602384. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
VL  - 55
ER  - 
TY  - INPR
A1  - Arrowsmith, Merle
A1  - Böhnke, Julian
A1  - Braunschweig, Holger
A1  - Celik, Mehmet Ali
T1  - Reactivity of a Dihydrodiborene with CO: Coordination, Insertion, Cleavage and Spontaneous Cyclic Alkyne Formation
T2  - Angewandte Chemie, International Edition
N2  - Under a CO atmosphere the dihydrodiborene [(cAAC)HB=BH(cAAC)] underwent coordination of CO concomitant with reversible hydrogen migration from boron to the carbene carbon atom, as well as reversible CO insertion into the B=B bond. Heating of the CO-adduct resulted in two unusual cAAC ring-expansion products, one presenting a B=C bond to a six-membered 1,2-azaborinane-3-ylidene, the other an unprecedented nine-membered cyclic alkyne resulting from reductive cleavage of CO and spontaneous C≡C triple bond formation.
KW  - CO activation
KW  - diborene
KW  - ring expansion
KW  - insertion
KW  - cyclic (alkyl)(amino)carbene
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-153318
N1  - This is the pre-peer reviewed version of the following article: Arrowsmith, M., Böhnke, J., Braunschweig, H. and Celik, M., Reactivity of a Dihydrodiborene with CO: Coordination, Insertion, Cleavage and Spontaneous Cyclic Alkyne Formation. Angew. Chem. Int. Ed. 2017, 129,14475 –14480. Accepted Author Manuscript. doi:10.1002/anie.201707907. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
ER  - 
TY  - INPR
A1  - Arrowsmith, Merle
A1  - Braunschweig, Holger
A1  - Stennett, Tom
T1  - Formation and Reactivity of Electron-Precise B–B Single and Multiple Bonds
T2  - Angewandte Chemie, International Edition
N2  - Recent years have seen rapid advances in the chemistry of small molecules containing electron-precise boron-boron bonds. This review provides an overview of the latest methods for the controlled synthesis of B–B single and multiple bonds as well as the ever-expanding range of reactivity displayed by the latter.
KW  - Boron
KW  - Main-group chemistry
KW  - Multiple bonding
KW  - Organoboron chemistry
KW  - Transition metals
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-145631
N1  - This is the pre-peer reviewed version of the following article: Angew.Chem. Int. Ed. 2017, 56,96–115, which has been published in final form at 10.1002/anie.201610072. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
N1  - Submitted Version
VL  - 56
IS  - 1
ER  - 
TY  - JOUR
A1  - Arnold, Thomas
A1  - Braunschweig, Holger
A1  - Gruss, Katrin
T1  - cyclo-Tri-mu-oxido-tris{[(eta 5,eta 5)-1,2-bis(cyclopentadienyl)-1,1,2,2-tetramethyldisilane]zirconium(IV)}: a trimeric disila-bridged oxidozirconocene
JF  - Acta Crystallographica Section E: metal-organic compounds
N2  - The title compound, [Zr(3)(C(14)H(20)Si(2))(3)O(3)], consists of three disila-bridged zirconocene units, which are connected via an oxide ligand, forming a nearly planar six-membered ring with a maximum displacement of 0.0191 (8) A. The compound was isolated as a by-product from a mixture of [(C(5)H(4)SiMe(2))(2)ZrCl(2)] and Li[AlH(4)] in Et(2)O.
KW  - Kristallographie
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134802
VL  - 67
ER  - 
TY  - JOUR
A1  - Arnold, Nicole
A1  - Braunschweig, Holger
A1  - Damme, Alexander
T1  - Bis(μ-diisopropyl-phosphanido-\(κ^2\)P:P)bis-[hydrido(triisopropyl-phosphane-κP)platinum(II)]
JF  - Acta crystallographica. Section E, Structure reports online
N2  - In the centrosymmetric molecular structure of the title compound \([Pt_2(C_6H_{14}P)_2H_2)(C_9H_{21}P)_2]\), each \(Pt^{II}\) atom is bound on one side to a phosphane ligand \((PiPr_3)\) and a hydrido ligand. On the other side, it is bound to two phosphanide ligands \((μ-PiPr_2)\), which engage a bridging position between the two \(Pt^{II}\) atoms, forming a distorted square-planar structure motif. The PtPt distance is 3.6755(2)Å. A comparable molecular structure was observed for bis-(μ-di-tert-butyl-phosphanido)bis-[hydrido(triethyl-phosphane)platinum(II)] [Itazaki et al. (2004 ). Organometallics, 23, 1610-1621].
KW  - data-to-parameter ratio = 22.3
KW  - mean σ(C–C) = 0.004 Å
KW  - single-crystal X-ray study
KW  - T = 100 K
KW  - R factor = 0.018
KW  - wR factor = 0.038
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123723
VL  - E68
ER  - 
TY  - JOUR
A1  - Ansell, Melvyn B.
A1  - Kostakis, George E.
A1  - Braunschweig, Holger
A1  - Navarro, Oscar
A1  - Spencer, John
T1  - Synthesis of functionalized hydrazines: facile homogeneous (N-heterocyclic carbene)-palladium(0)-catalyzed diboration and silaboration of azobenzenes
JF  - Advanced Synthesis & Catalysis
N2  - The bis(N-heterocyclic carbene)(diphenylacetylene)palladium complex Pd(ITMe)\(_2\)(PhCCPh)] (ITMe=1,3,4,5-tetramethylimidazol-2-ylidene) acts as a highly active pre-catalyst in the diboration and silaboration of azobenzenes to synthesize a series of novel functionalized hydrazines. The reactions proceed using commercially available diboranes and silaboranes under mild reaction conditions.
KW  - Palladium-catalyzed silaboration
KW  - B-B bond
KW  - molecular-structure
KW  - terminal alkynes
KW  - crystal-structure
KW  - alkenes
KW  - complexes
KW  - mechanism
KW  - boron
KW  - design
KW  - azobenzenes
KW  - dilaboration
KW  - N-heterocyclic carbenes
KW  - palladium
KW  - silaboration
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186582
VL  - 358
IS  - 23
ER  -