@article{LenczykRoyOberdorfetal.2019, author = {Lenczyk, Carsten and Roy, Dipak Kumar and Oberdorf, Kai and Nitsch, J{\"o}rn and Dewhurst, Rian D. and Radacki, Krzysztof and Halet, Jean-Fran{\c{c}}ois and Marder, Todd B. and Bickelhaupt, Matthias and Braunschweig, Holger}, title = {Toward Transition-Metal-Templated Construction of Arylated B\(_{4}\) Chains by Dihydroborane Dehydrocoupling}, series = {Chemistry - A European Journal}, volume = {25}, journal = {Chemistry - A European Journal}, number = {72}, doi = {10.1002/chem.201904772}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-214324}, pages = {16544-16549}, year = {2019}, abstract = {The reactivity of a diruthenium tetrahydride complex towards three selected dihydroboranes was investigated. The use of [DurBH\(_{2}\)] (Dur=2,3,5,6-Me\(_{4}\)C\(_{6}\)H) and [(Me\(_{3}\)Si)\(_{2}\)NBH\(_{2}\)] led to the formation of bridging borylene complexes of the form [(Cp\(^{*}\)RuH)\(_{2}\)BR] (Cp\(^{*}\)=C\(_{5}\)Me\(_{5}\); 1 a: R=Dur; 1 b: R=N(SiMe\(_{3}\))\(_{2}\)) through oxidative addition of the B-H bonds with concomitant hydrogen liberation. Employing the more electron-deficient dihydroborane [3,5-(CF\(_{3}\))\(_{2}\)-C\(_{6}\)H\(_{3}\)BH\(_{2}\)] led to the formation of an anionic complex bearing a tetraarylated chain of four boron atoms, namely Li(THF)\(_{4}\)[(Cp\(^{*}\)Ru)\(_{2}\)B\(_{4}\)H\(_{5}\)(3,5-(CF\(_{3}\))\(_{2}\)C\(_{6}\)H\(_{3}\))\(_{4}\)] (4), through an unusual, incomplete threefold dehydrocoupling process. A comparative theoretical investigation of the bonding in a simplified model of 4 and the analogous complex nido-[1,2(Cp\(^{*}\)Ru)\(_{2}\)(μ-H)B\(_{4}\)H\(_{9}\)] (I) indicates that there appear to be no classical σ-bonds between the boron atoms in complex I, whereas in the case of 4 the B\(_{4}\) chain better resembles a network of three B-B σ bonds, the central bond being significantly weaker than the other two.}, language = {en} } @article{MuessigLisinetskayaDewhurstetal.2020, author = {Muessig, Jonas H. and Lisinetskaya, Polina and Dewhurst, Rian D. and Bertermann, R{\"u}diger and Thaler, Melanie and Mitric, Roland and Braunschweig, Holger}, title = {Tetraiododiborane(4) (B\(_2\)I\(_4\)) is a Polymer based on sp\(^3\) Boron in the Solid State}, series = {Angewandte Chemie International Edition}, volume = {59}, journal = {Angewandte Chemie International Edition}, doi = {10.1002/anie.201913590}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-209428}, pages = {5531-5535}, year = {2020}, abstract = {Herein we present the first solid-state structures of tetraiododiborane(4) (B\(_2\)I\(_4\)), which was long believed to exist in all phases as discrete molecules with planar, tricoordinate boron atoms, like the lighter tetrahalodiboranes(4) B\(_2\)F\(_4\), B\(_2\)Cl\(_4\), and B\(_2\)Br\(_4\). Single-crystal X-ray diffraction, solid-state NMR, and IR measurements indicate that B\(_2\)I\(_4\) in fact exists as two different polymeric forms in the solid state, both of which feature boron atoms in tetrahedral environments. DFT calculations are used to simulate the IR spectra of the solution and solid-state structures, and these are compared with the experimental spectra.}, language = {en} } @article{AnsellKostakisBraunschweigetal.2016, author = {Ansell, Melvyn B. and Kostakis, George E. and Braunschweig, Holger and Navarro, Oscar and Spencer, John}, title = {Synthesis of functionalized hydrazines: facile homogeneous (N-heterocyclic carbene)-palladium(0)-catalyzed diboration and silaboration of azobenzenes}, series = {Advanced Synthesis \& Catalysis}, volume = {358}, journal = {Advanced Synthesis \& Catalysis}, number = {23}, doi = {10.1002/adsc.201601106}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-186582}, pages = {3765-3769}, year = {2016}, abstract = {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.}, language = {en} } @article{BruecknerDewhurstDellermannetal.2019, author = {Br{\"u}ckner, Tobias and Dewhurst, Rian D. and Dellermann, Theresa and M{\"u}ller, Marcel and Braunschweig, Holger}, title = {Mild synthesis of diboryldiborenes by diboration of B-B triple bonds}, series = {Chemical Science}, volume = {10}, journal = {Chemical Science}, doi = {10.1039/C9SC02544H}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-186306}, pages = {7375-7378}, year = {2019}, abstract = {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.}, language = {en} } @article{BoehnkeBruecknerHermannetal.2018, author = {B{\"o}hnke, Julian and Br{\"u}ckner, Tobias and Hermann, Alexander and Gonz{\´a}lez-Belman, Oscar F. and Arrowsmith, Merle and Jim{\´e}nez-Halla, J. Oscar C. and Braunschweig, Holger}, title = {Single and double activation of acetone by isolobal B≡N and B≡B triple bonds}, series = {Chemical Science}, volume = {9}, journal = {Chemical Science}, doi = {10.1039/c8sc01249k}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164286}, pages = {5354-5359}, year = {2018}, abstract = {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.}, language = {en} } @article{BoehnkeDellermannCeliketal.2018, author = {B{\"o}hnke, Julian and Dellermann, Theresa and Celik, Mehmet Ali and Krummenacher, Ivo and Dewhurst, Rian D. and Demeshko, Serhiy and Ewing, William C. and Hammond, Kai and Heß, Merlin and Bill, Eckhard and Welz, Eileen and R{\"o}hr, Merle I. S. and Mitric, Roland and Engels, Bernd and Meyer, Franc and Braunschweig, Holger}, title = {Isolation of diborenes and their 90°-twisted diradical congeners}, series = {Nature Communications}, volume = {9}, journal = {Nature Communications}, number = {Article number: 1197}, doi = {10.1038/s41467-018-02998-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-160431}, year = {2018}, abstract = {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.}, language = {en} }