Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-16024 unpublished Böhnke, Julian; Dellermann, Theresa; Celik, Mehmet Ali; Krummenacher, Ivo; Dewhurst, Rian D.; Demeshko, Serhiy; Ewing, William C.; Hammond, Kai; Heß, Merlin; Bill, Eckhard; Welz, Eileen; Röhr, Merle I. S.; Mitric, Roland; Engels, Bernd; Meyer, Franc; Braunschweig, Holger Isolation of diradical products of twisted double bonds 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of compound. 2018 Nature Communications urn:nbn:de:bvb:20-opus-160248 Institut für Anorganische Chemie OPUS4-18863 unpublished Brückner, Tobias; Stennett, Tom E.; Heß, Merlin; Braunschweig, Holger Single and Double Hydroboration of B-B Triple Bonds and Conver- gent Routes to a Cationic Tetraborane 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. 2019 Journal of the American Chemical Society urn:nbn:de:bvb:20-opus-188632 10.1021/jacs.9b07991 Institut für Anorganische Chemie OPUS4-18489 unpublished Brückner, Tobias; Arrowsmith, Merle; Heß, Merlin; Hammond, Kai; Müller, Marcel; Braunschweig, Holger Synthesis of fused B,N-heterocycles by alkyne cleavage, NHC ring-expansion and C-H activation at a diboryne 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. 2019 Chemical Communications urn:nbn:de:bvb:20-opus-184899 10.1039/C9CC02657F Institut für Anorganische Chemie OPUS4-13823 Wissenschaftlicher Artikel Braunschweig, Holger; Constantinidis, Philipp; Dellermann, Theresa; Ewing, William; Fischer, Ingo; Hess, Merlin; Knight, Fergus; Rempel, Anna; Schneider, Christoph; Ullrich, Stefan; Vargas, Alfredo; Woolins, Derek Highly Strained Heterocycles Constructed from Boron-Boron Multiple Bonds and Heavy Chalcogens 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. 2016 4 Angewandte Chemie, International Edition 55 18 5606 5609 urn:nbn:de:bvb:20-opus-138237 10.1002/anie.201601691 Institut für Anorganische Chemie OPUS4-16043 Wissenschaftlicher Artikel Böhnke, Julian; Dellermann, Theresa; Celik, Mehmet Ali; Krummenacher, Ivo; Dewhurst, Rian D.; Demeshko, Serhiy; Ewing, William C.; Hammond, Kai; Heß, Merlin; Bill, Eckhard; Welz, Eileen; Röhr, Merle I. S.; Mitric, Roland; Engels, Bernd; Meyer, Franc; Braunschweig, Holger Isolation of diborenes and their 90°-twisted diradical congeners 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. 2018 Nature Communications 9 Article number: 1197 urn:nbn:de:bvb:20-opus-160431 10.1038/s41467-018-02998-3 Institut für Anorganische Chemie OPUS4-24066 Wissenschaftlicher Artikel Brückner, Tobias; Heß, Merlin; Stennett, Tom E.; Rempel, Anna; Braunschweig, Holger Synthesis of Boron Analogues of Enamines via Hydroamination of a Boron-Boron Triple Bond An N-heterocyclic-carbene-stabilized diboryne undergoes rapid, high-yielding and catalyst-free hydroamina- tion reactions with primary amines, yielding 1-amino-2-hydro- diborenes, which can be considered boron analogues of enamines. The electronics of the organic substituent at nitrogen influence the structure and further reactivity of the diborene product. With electron-rich anilines, a second hydroamination can occur at the diborene to generate 1,1-diamino-2,2-dihy- drodiboranes. With isopropylamine, the electronic influence of the alkyl substituent upon the diborene leads to an unprece- dented boron-mediated intramolecular N-dearylation reaction of an N-heterocyclic carbene unit. 2021 736-741 Angewandte Chemie, International Edition 60 2 urn:nbn:de:bvb:20-opus-240669 10.1002/anie.202012101 Institut für Anorganische Chemie OPUS4-25683 Wissenschaftlicher Artikel Heß, Merlin; Krummenacher, Ivo; Dellermann, Theresa; Braunschweig, Holger Rhodium-Mediated Stoichiometric Synthesis of Mono-, Bi-, and Bis-1,2-Azaborinines: 1-Rhoda-3,2-azaboroles as Reactive Precursors A series of highly substituted 1,2-azaborinines, including a phenylene-bridged bis-1,2-azaborinine, was synthesized from the reaction of 1,2-azaborete rhodium complexes with variously substituted alkynes. 1-Rhoda-3,2-azaborole complexes, which are accessible by phosphine addition to the corresponding 1,2-azaborete complexes, were also found to be suitable precursors for the synthesis of 1,2-azaborinines and readily reacted with alkynyl-substituted 1,2-azaborinines to generate new regioisomers of bi-1,2-azaborinines, which feature directly connected aromatic rings. Their molecular structures, which can be viewed as boron-nitrogen isosteres of biphenyls, show nearly perpendicular 1,2-azaborinine rings. The new method using rhodacycles instead of 1,2-azaborete complexes as precursors is shown to be more effective, allowing the synthesis of a wider range of 1,2-azaborinines. 2021 9503–9507 Chemistry—A European Journal 27 37 urn:nbn:de:bvb:20-opus-256830 10.1002/chem.202100795 Institut für Anorganische Chemie