@article{KleinJoheWagneretal.2020,
  author    = {Klein, Philipp and Johe, Patrick and Wagner, Annika and Jung, Sascha and K{\"u}hlborn, Jonas and Barthels, Fabian and Tenzer, Stefan and Distler, Ute and Waigel, Waldemar and Engels, Bernd and Hellmich, Ute A. and Opatz, Till and Schirmeister, Tanja},
  title     = {New cysteine protease inhibitors: electrophilic (het)arenes and unexpected prodrug identification for the Trypanosoma protease rhodesain},
  series = {Molecules},
  volume    = {25},
  journal   = {Molecules},
  number    = {6},
  issn      = {1420-3049},
  doi       = {10.3390/molecules25061451},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203380},
  year      = {2020},
  abstract  = {Electrophilic (het)arenes can undergo reactions with nucleophiles yielding π- or Meisenheimer (σ-) complexes or the products of the S\(_N\)Ar addition/elimination reactions. Such building blocks have only rarely been employed for the design of enzyme inhibitors. Herein, we demonstrate the combination of a peptidic recognition sequence with such electrophilic (het)arenes to generate highly active inhibitors of disease-relevant proteases. We further elucidate an unexpected mode of action for the trypanosomal protease rhodesain using NMR spectroscopy and mass spectrometry, enzyme kinetics and various types of simulations. After hydrolysis of an ester function in the recognition sequence of a weakly active prodrug inhibitor, the liberated carboxylic acid represents a highly potent inhibitor of rhodesain (K\(_i\) = 4.0 nM). The simulations indicate that, after the cleavage of the ester, the carboxylic acid leaves the active site and re-binds to the enzyme in an orientation that allows the formation of a very stable π-complex between the catalytic dyad (Cys-25/His-162) of rhodesain and the electrophilic aromatic moiety. The reversible inhibition mode results because the S\(_N\)Ar reaction, which is found in an alkaline solvent containing a low molecular weight thiol, is hindered within the enzyme due to the presence of the positively charged imidazolium ring of His-162. Comparisons between measured and calculated NMR shifts support this interpretation},
  language  = {en}
}
@article{KleinBarthelsJoheetal.2020,
  author    = {Klein, Philipp and Barthels, Fabian and Johe, Patrick and Wagner, Annika and Tenzer, Stefan and Distler, Ute and Le, Thien Anh and Schmid, Paul and Engel, Volker and Engels, Bernd and Hellmich, Ute A. and Opatz, Till and Schirmeister, Tanja},
  title     = {Naphthoquinones as covalent reversible inhibitors of cysteine proteases — studies on inhibition mechanism and kinetics},
  series = {Molecules},
  volume    = {25},
  journal   = {Molecules},
  number    = {9},
  issn      = {1420-3049},
  doi       = {10.3390/molecules25092064},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203791},
  year      = {2020},
  abstract  = {The facile synthesis and detailed investigation of a class of highly potent protease inhibitors based on 1,4-naphthoquinones with a dipeptidic recognition motif (HN-l-Phe-l-Leu-OR) in the 2-position and an electron-withdrawing group (EWG) in the 3-position is presented. One of the compound representatives, namely the acid with EWG = CN and with R = H proved to be a highly potent rhodesain inhibitor with nanomolar affinity. The respective benzyl ester (R = Bn) was found to be hydrolyzed by the target enzyme itself yielding the free acid. Detailed kinetic and mass spectrometry studies revealed a reversible covalent binding mode. Theoretical calculations with different density functionals (DFT) as well as wavefunction-based approaches were performed to elucidate the mode of action.},
  language  = {en}
}
@article{PreitschopfSturmStroganovaetal.2023,
  author    = {Preitschopf, Tobias and Sturm, Floriane and Stroganova, Iuliia and Lemmens, Alexander K. and Rijs, Anouk M. and Fischer, Ingo},
  title     = {IR/UV Double Resonance Study of the 2-Phenylallyl Radical and its Pyrolysis Products},
  series = {Chemistry - A European Journal},
  volume    = {29},
  journal   = {Chemistry - A European Journal},
  number    = {13},
  doi       = {10.1002/chem.202202943},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312338},
  year      = {2023},
  abstract  = {Isolated 2-phenylallyl radicals (2-PA), generated by pyrolysis from a nitrite precursor, have been investigated by IR/UV ion dip spectroscopy using free electron laser radiation. 2-PA is a resonance-stabilized radical that is considered to be involved in the formation of polycyclic aromatic hydrocarbons (PAH) in combustion, but also in interstellar space. The radical is identified based on its gas-phase IR spectrum. Furthermore, a number of bimolecular reaction products are identified, showing that the self-reaction as well as reactions with unimolecular decomposition products of 2-PA form several PAH efficiently. Possible mechanisms are discussed and the chemistry of 2-PA is compared with the one of the related 2-methylallyl and phenylpropargyl radicals.},
  language  = {en}
}
@article{BruneckerMuessigArrowsmithetal.2020,
  author    = {Brunecker, Carina and M{\"u}ssig, Jonas H. and Arrowsmith, Merle and Fantuzzi, Felipe and Stoy, Andreas and B{\"o}hnke, Julian and Hofmann, Alexander and Bertermann, R{\"u}diger and Engels, Bernd and Braunschweig, Holger},
  title     = {Boranediyl- and Diborane(4)-1,2-diyl-Bridged Platinum A-Frame Complexes},
  series = {Chemistry - A European Journal},
  volume    = {26},
  journal   = {Chemistry - A European Journal},
  number    = {39},
  doi       = {10.1002/chem.202001168},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-214707},
  pages     = {8518 -- 8523},
  year      = {2020},
  abstract  = {Diplatinum A-frame complexes with a bridging (di)boron unit in the apex position were synthesized in a single step by the double oxidative addition of dihalo(di)borane precursors at a bis(diphosphine)-bridged Pt\(^{0}\)\(_{2}\) complex. While structurally analogous to well-known μ-borylene complexes, in which delocalized dative three-center-two-electron M-B-M bonding prevails, theoretical investigations into the nature of Pt-B bonding in these A-frame complexes show them to be rare dimetalla(di)boranes displaying two electron-sharing Pt-B σ-bonds. This is experimentally reflected in the low kinetic stability of these compounds, which are prone to loss of the (di)boron bridgehead unit.},
  language  = {en}
}
@article{HagspielFantuzziDewhurstetal.2021,
  author    = {Hagspiel, Stephan and Fantuzzi, Felipe and Dewhurst, Rian D. and G{\"a}rtner, Annalena and Lindl, Felix and Lamprecht, Anna and Braunschweig, Holger},
  title     = {Addukte des Stammboraphosphaketens H\(_{2}\)BPCO und deren Insertionsreaktionen mittels Decarbonylierung},
  series = {Angewandte Chemie},
  volume    = {133},
  journal   = {Angewandte Chemie},
  number    = {24},
  doi       = {10.1002/ange.202103521},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244803},
  pages     = {13780 -- 13784},
  year      = {2021},
  abstract  = {Die ersten Beispiele f{\"u}r Lewis-Basen-Addukte des Stammboraphosphaketens H\(_{2}\)B-PCO und ihre cyclischen Dimere wurden hergestellt. Eines dieser Addukte zeigt unter milden Bedingungen eine Decarbonylierung und anschließende Insertion des Phosphinidens in die B-C-Bindung eines Borols, was in der Bildung sehr seltener Beispiele f{\"u}r 1,2-Phosphaborinine, B,P-Isostere von Benzol, resultiert. Die starken Donoreigenschaften dieser 1,2-Phosphaborinine wurden durch die Synthese ihrer π-Komplexe mit Metallen der Gruppe 6 best{\"a}tigt.},
  language  = {de}
}
@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{RangFantuzziArrowsmithetal.2021,
  author    = {Rang, Maximilian and Fantuzzi, Felipe and Arrowsmith, Merle and Krummenacher, Ivo and Beck, Eva and Witte, Robert and Matler, Alexander and Rempel, Anna and Bischof, Tobias and Radacki, Krzysztof and Engels, Bernd and Braunschweig, Holger},
  title     = {Reduktion und Umlagerung eines Bor(I)-Carbonylkomplexes},
  series = {Angewandte Chemie},
  volume    = {133},
  journal   = {Angewandte Chemie},
  number    = {6},
  doi       = {10.1002/ange.202014167},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224409},
  pages     = {3000 -- 3005},
  year      = {2021},
  abstract  = {Bei der Einelektronenreduktion eines durch eine cyclisches (Alkyl)(amino)carben (CAAC) stabilisierten Arylborylen-Carbonylkomplexes erfolgt die Bildung eines dimeren Borylketyl-Radikalanions, bedingt durch eine intramolekulare Arylmigration zum CO Kohlenstoffatom. Computergest{\"u}tzte Analyse liefert Hinweise auf eine radikalanionische [(CAAC)B(CO)Ar]\(^{.-}\) Zwischenstufe. Weiterf{\"u}hrende Reduktion des entstandenen Komplexes liefert ein hoch nukleophiles (Boranyliden)methanolat.},
  language  = {de}
}
@article{RoedingBrixner2018,
  author    = {Roeding, Sebastian and Brixner, Tobias},
  title     = {Coherent two-dimensional electronic mass spectrometry},
  series = {Nature Communications},
  volume    = {9},
  journal   = {Nature Communications},
  number    = {2519},
  doi       = {10.1038/s41467-018-04927-w},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226458},
  pages     = {1-9},
  year      = {2018},
  abstract  = {Coherent two-dimensional (2D) optical spectroscopy has revolutionized our ability to probe many types of couplings and ultrafast dynamics in complex quantum systems. The dynamics and function of any quantum system strongly depend on couplings to the environment. Thus, studying coherent interactions for different environments remains a topic of tremendous interest. Here we introduce coherent 2D electronic mass spectrometry that allows 2D measurements on effusive molecular beams and thus on quantum systems with minimum system-bath interaction and employ this to identify the major ionization pathway of 3d Rydberg states in NO2. Furthermore, we present 2D spectra of multiphoton ionization, disclosing distinct differences in the nonlinear response functions leading to the ionization products. We also realize the equivalent of spectrally resolved transient-absorption measurements without the necessity for acquiring weak absorption changes. Using time-of-flight detection introduces cations as an observable, enabling the 2D spectroscopic study on isolated systems of photophysical and photochemical reactions.},
  language  = {en}
}