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  - 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  - 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  - JOUR
A1  - Böhnke, Julian
A1  - Brückner, Tobias
A1  - Hermann, Alexander
A1  - González-Belman, Oscar F.
A1  - Arrowsmith, Merle
A1  - Jiménez-Halla, J. Oscar C.
A1  - Braunschweig, Holger
T1  - Single and double activation of acetone by isolobal B≡N and B≡B triple bonds
JF  - Chemical Science
N2  - B≡N and B≡B triple bonds induce C-H activation of acetone to yield a (2-propenyloxy)aminoborane and an unsymmetrical 1-(2- propenyloxy)-2-hydrodiborene, respectively. DFT calculations showed that, despite their stark electronic differences, both the B≡N and B≡B triple bonds activate acetone via a similar coordination-deprotonation mechansim. In contrast, the reaction of acetone with a cAAC-supported diboracumulene yielded a unique 1,2,3-oxadiborole, which according to DFT calculations also proceeds via an unsymmetrical diborene, followed by intramolecular hydride migration and a second C-H activation of the enolate ligand.
KW  - acetone
KW  - diborynes
KW  - iminoboranes
KW  - boron
KW  - small-molecule activation
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164286
VL  - 9
ER  - 
TY  - JOUR
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 diborenes and their 90°-twisted diradical congeners
JF  - 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  - chemical bonding
KW  - diradicals
KW  - organometallic chemistry
KW  - diborenes
KW  - carbenes
KW  - boron
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-160431
VL  - 9
IS  - Article number: 1197
ER  - 
TY  - JOUR
A1  - Brückner, Tobias
A1  - Dewhurst, Rian D.
A1  - Dellermann, Theresa
A1  - Müller, Marcel
A1  - Braunschweig, Holger
T1  - Mild synthesis of diboryldiborenes by diboration of B–B triple bonds
JF  - Chemical Science
N2  - A set of diboryldiborenes are prepared by the mild, catalyst-free, room-temperature diboration of the B–B triple bonds of doubly base-stabilized diborynes. Two of the product diboryldiborenes are found to be air- and water-stable in the solid state, an effect that is attributed to their high crystallinity and extreme insolubility in a wide range of solvents.
KW  - boron
KW  - diborenes
KW  - diboration
KW  - triple bonds
KW  - diborynes
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186306
VL  - 10
ER  - 
TY  - JOUR
A1  - Stennett, Tom E.
A1  - Jayaraman, Arumugam
A1  - Brückner, Tobias
A1  - Schneider, Lea
A1  - Braunschweig, Holger
T1  - Hydrophosphination of boron–boron multiple bonds
JF  - Chemical Science
N2  - Five compounds containing boron–boron multiple bonds are shown to undergo hydrophosphination reactions with diphenylphosphine in the absence of a catalyst. With diborenes, the products obtained are highly dependent on the substitution pattern at the boron atoms, with both 1,1- and 1,2- hydrophosphinations observed. With a symmetrical diboryne, 1,2-hydrophosphination yields a hydro(phosphino)diborene. The different mechanistic pathways for the hydrophosphination of diborenes are rationalised with the aid of density functional theory calculations.
KW  - boron
KW  - diborenes
KW  - diborynes
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-240681
VL  - 11
ER  - 
TY  - JOUR
A1  - Liu, Siyuan
A1  - Légaré, Marc-André
A1  - Seufert, Jens
A1  - Prieschl, Dominic
A1  - Rempel, Anna
A1  - Englert, Lukas
A1  - Dellermann, Theresa
A1  - Paprocki, Valerie
A1  - Stoy, Andreas
A1  - Braunschweig, Holger
T1  - 2,2′-Bipyridyl as a Redox-Active Borylene Abstraction Agent
JF  - Inorganic Chemistry
N2  - 2,2′-Bipyridyl is shown to spontaneously abstract a borylene fragment (R–B:) from various hypovalent boron compounds. This process is a redox reaction in which the bipyridine is reduced and becomes a dianionic substituent bound to boron through its two nitrogen atoms. Various transition metal–borylene complexes and diboranes, as a well as a diborene, take part in this reaction. In the latter case, our results show an intriguing example of the homolytic cleavage of a B═B double bond.
KW  - Borylene
KW  - Heterocycles
KW  - Boron
KW  - Main-group chemistry
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-215595
N1  - This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Inorganic Chemistry, copyright © American Chemical Society after peer review. To access the final edited and published work see https://doi.org/10.1021/acs.inorgchem.0c01383.
VL  - 59
IS  - 15
ER  - 
TY  - JOUR
A1  - Ewing, William C.
A1  - Dellermann, Theresa
A1  - Angel Wong, Y. T.
A1  - Mattock, James D.
A1  - Vargas, Alfredo
A1  - Bryce, David L.
A1  - Dewhurst, Rian D.
A1  - Braunschweig, Holger
T1  - \(\pi\)‐Complexes of Diborynes with Main Group Atoms
JF  - Chemistry – An Asian Journal
N2  - We present herein an in‐depth study of complexes in which a molecule containing a boron‐boron triple bond is bound to tellurate cations. The analysis allows the description of these salts as true π complexes between the B−B triple bond and the tellurium center. These complexes thus extend the well‐known Dewar‐Chatt‐Duncanson model of bonding to compounds made up solely of p block elements. Structural, spectroscopic and computational evidence is offered to argue that a set of recently reported heterocycles consisting of phenyltellurium cations complexed to diborynes bear all the hallmarks of \(\pi\)‐complexes in the \(\pi\)‐complex/metallacycle continuum envisioned by Joseph Chatt. Described as such, these compounds are unique in representing the extreme of a metal‐free continuum with conventional unsaturated three‐membered rings (cyclopropenes, azirenes, borirenes) occupying the opposite end.
KW  - boron
KW  - main group elements
KW  - solid-state NMR
KW  - \(\pi\) interactions
KW  - multiple bonds
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214677
VL  - 15
IS  - 10
SP  - 1553
EP  - 1557
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  - 
TY  - JOUR
A1  - Huang, Zhenguo
A1  - Wang, Suning
A1  - Dewhurst, Rian D.
A1  - Ignat'ev, Nikolai V.
A1  - Finze, Maik
A1  - Braunschweig, Holger
T1  - Boron: Its Role in Energy‐Related Processes and Applications
JF  - Angewandte Chemie International Edition
N2  - Boron's unique position in the Periodic Table, that is, at the apex of the line separating metals and nonmetals, makes it highly versatile in chemical reactions and applications. Contemporary demand for renewable and clean energy as well as energy‐efficient products has seen boron playing key roles in energy‐related research, such as 1) activating and synthesizing energy‐rich small molecules, 2) storing chemical and electrical energy, and 3) converting electrical energy into light. These applications are fundamentally associated with boron's unique characteristics, such as its electron‐deficiency and the availability of an unoccupied p orbital, which allow the formation of a myriad of compounds with a wide range of chemical and physical properties. For example, boron's ability to achieve a full octet of electrons with four covalent bonds and a negative charge has led to the synthesis of a wide variety of borate anions of high chemical and electrochemical stability—in particular, weakly coordinating anions. This Review summarizes recent advances in the study of boron compounds for energy‐related processes and applications.
KW  - boron
KW  - electrolytes
KW  - hydrogen
KW  - OLEDs
KW  - small-molecule activation
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218514
VL  - 59
IS  - 23
SP  - 8800
EP  - 8816
ER  - 
TY  - JOUR
A1  - Brückner, Tobias
A1  - Fantuzzi, Felipe
A1  - Stennett, Tom E.
A1  - Krummenacher, Ivo
A1  - Dewhurst, Rian D.
A1  - Engels, Bernd
A1  - Braunschweig, Holger
T1  - Isolation of neutral, mono-, and dicationic B\(_2\)P\(_2\) rings by diphosphorus addition to a boron-boron triple bond
JF  - Angewandte Chemie International Edition
N2  - The NHC-stabilised diboryne (B\(_2\)(SIDep)\(_2\); SIDep=1,3-bis(2,6-diethylphenyl)imidazolin-2-ylidene) undergoes a high-yielding P−P bond activation with tetraethyldiphosphine at room temperature to form a B\(_2\)P\(_2\) heterocycle via a diphosphoryldiborene by 1,2-diphosphination. The heterocycle can be oxidised to a radical cation and a dication, respectively, depending on the oxidant used and its counterion. Starting from the planar, neutral 1,3-bis(alkylidene)-1,3-diborata-2,4-diphosphoniocyclobutane, each oxidation step leads to decreased B−B distances and loss of planarity by cationisation. X-ray analyses in conjunction with DFT and CASSCF/NEVPT2 calculations reveal closed-shell singlet, butterfly-shaped structures for the NHC-stabilised dicationic B\(_2\)P\(_2\) rings, with their diradicaloid, planar-ring isomers lying close in energy.
KW  - inorganic chemistry
KW  - radicals
KW  - boron
KW  - density functional calculations
KW  - oxidation
KW  - phosphorus heterocycles
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256451
VL  - 60
IS  - 24
ER  - 
TY  - JOUR
A1  - Brückner, Tobias
A1  - Heß, Merlin
A1  - Stennett, Tom E.
A1  - Rempel, Anna
A1  - Braunschweig, Holger
T1  - Synthesis of Boron Analogues of Enamines via Hydroamination of a Boron-Boron Triple Bond
BT  - Dedicated to Professor Wolfgang Kaim on the occasion of his 70th birthday
JF  - Angewandte Chemie, International Edition
N2  - 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.
KW  - boron
KW  - diborynes
KW  - diborenes
KW  - DFT
KW  - enamines
KW  - hydroamination
KW  - multiple bonds
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-240669
VL  - 60
IS  - 2
ER  - 
TY  - JOUR
A1  - Lu, Wei
A1  - Jayaraman, Arumugam
A1  - Fantuzzi, Felipe
A1  - Dewhurst, Rian D.
A1  - Härterich, Marcel
A1  - Dietz, Maximilian
A1  - Hagspiel, Stephan
A1  - Krummenbacher, Ivo
A1  - Hammond, Kai
A1  - Cui, Jingjing
A1  - Braunschweig, Holger
T1  - An unsymmetrical, cyclic diborene based on a chelating CAAC ligand and its small-molecule activation and rearrangement chemistry
JF  - Angewandte Chemie International Edition
N2  - A one-pot synthesis of a CAAC-stabilized, unsymmetrical, cyclic diborene was achieved via consecutive two-electron reduction steps from an adduct of CAAC and B\(_2\)Br\(_4\)(SMe\(_2\))\(_2\). Theoretical studies revealed that this diborene has a considerably smaller HOMO–LUMO gap than those of reported NHC- and phosphine-supported diborenes. Complexation of the diborene with [AuCl(PCy\(_3\))] afforded two diborene–Au\(^I\) π complexes, while reaction with DurBH\(_2\), P\(_4\) and a terminal acetylene led to the cleavage of B−H, P−P, and C−C π bonds, respectively. Thermal rearrangement of the diborene gave an electron-rich cyclic alkylideneborane, which readily coordinated to Ag\(^I\) via its B=C double bond.
KW  - inorganic chemistry
KW  - thermal rearrangement
KW  - alkylideneborane
KW  - carbene
KW  - diborene
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256576
VL  - 61
IS  - 3
ER  - 
TY  - JOUR
A1  - Brückner, Tobias
A1  - Ritschel, Benedikt
A1  - Jiménez‐Halla, J. Oscar C.
A1  - Fantuzzi, Felipe
A1  - Duwe, Dario
A1  - Markl, Christian
A1  - Dewhurst, Rian D.
A1  - Dietz, Maximilian
A1  - Braunschweig, Holger
T1  - Metal‐Free Intermolecular C−H Borylation of N‐Heterocycles at B−B Multiple Bonds
JF  - Angewandte Chemie International Edition
N2  - Carbene‐stabilized diborynes of the form LBBL (L=N‐heterocyclic carbene (NHC) or cyclic alkyl(amino)carbene (CAAC)) induce rapid, high yielding, intermolecular ortho‐C−H borylation at N‐heterocycles at room temperature. A simple pyridyldiborene is formed when an NHC‐stabilized diboryne is combined with pyridine, while a CAAC‐stabilized diboryne leads to activation of two pyridine molecules to give a tricyclic alkylideneborane, which can be forced to undergo a further H‐shift resulting in a zwitterionic, doubly benzo‐fused 1,3,2,5‐diazadiborinine by heating. Use of the extended N‐heteroaromatic quinoline leads to a borylmethyleneborane under mild conditions via an unprecedented boron‐carbon exchange process.
KW  - Boron
KW  - Borylation
KW  - Carbene
KW  - Diboryne
KW  - Hydroarylation
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312385
VL  - 62
IS  - 5
ER  -