Potent nucleophilicity yet low basicity : A 1,3,2-diazaphospholene (DAP) catalyst in conjunction with PhSiH3 enables the direct conjugate reduction of substituted α,β-unsaturated carboxylic acids without prior deprotonation, highlighting its remarkably potent nucleophilicity and yet low basicity. The transformation is characterized by a low catalyst loading, mild reaction conditions at ambient temperature as well as fast reaction times and tolerates functional groups such as Cbz group or alkyl halides that can be problematic with classical reduction catalysts.
[Communications]
John H. Reed, Prof. Nicolai Cramer
doi.org/10.1002/cctc.202000662
Revealing the ties that bind : The nature of molecular interactions at the interface between aluminum-based adjuvants and antigens in vaccine formulations is elucidated by using correlation magic angle spinning dynamic nuclear polarization (MAS DNP) NMR spectroscopy. Data reveal significant differences in these interactions as a function of the adjuvant supplier (see figure).
[Full Papers]
Dr. Jasmine Viger-Gravel, Dr. Federico M. Paruzzo, Dr. Corine Cazaux, Ribal Jabbour, Dr. Amandine Leleu, Dr. Françoise Canini, Dr. Pierre Florian, Dr. Frédéric Ronzon, Dr. David Gajan, Dr. Anne Lesage
doi.org/10.1002/chem.202001141
One up, one down : RuII polypyridyl complexes are prime candidates for the development of new photosensitizers for photodynamic therapy. Increasing their lipophilicity could result in improved pharmacological properties. The relationship between lipophilicity and in vitro phototoxicity of halogenated RuII complexes was investigated.
[Full Papers]
Dr. Saonli Roy, Elisa Colombo, Dr. Robin Vinck, Dr. Cristina Mari, Dr. Riccardo Rubbiani, Dr. Malay Patra, Dr. Gilles Gasser
doi.org/10.1002/cbic.202000289
Nitrenium conundrum : When exploring synthetic-scale generation of stable diarylnitrenium ions, Ar2N+, we find products quite different to those derived from photochemical generation.
[Communications]
Dr. Agnes Kütt, Prof. Dr. Gunnar Jeschke, Dr. Lauri Toom, Dr. Jaak Nerut, Prof. Christopher A. Reed
doi.org/10.1002/chem.202000930
New tools for GluN2A-containing NMDA receptors have been discovered through the optimization of 5H-thiazolo[3,2-α]pyrimidin-5-one derivatives. The radioligand [18F]7b provided high-quality images in autoradiographic studies, while its tritiated analogue [3H2]15b allowed the development of a radioligand binding assay, useful for the study of GluN2A-containing NMDA receptors and the optimization of allosteric modulators binding at the GluN1-GluN2A interface.
[Full Papers]
Yingfang He, Dr. David M. Whitehead, Dr. Emmanuelle Briard, Dr. Shin Numao, Dr. Linjing Mu, Prof. Roger Schibli, Prof. Simon M. Ametamey, Dr. Yves P. Auberson
doi.org/10.1002/cmdc.202000340
The propensity of centrosymmetric multibranched dyes to undergo symmetry breaking was controlled by tuning their change of quadrupole moment upon excitation, ΔQ . This was achieved by varying the length, as well as the strength, of the acceptor arms around the donor core.
[Articles]
Dr. Zoltán Szakács, Dr. Mariusz Tasior, Prof. Daniel T. Gryko, Prof. Eric Vauthey
doi.org/10.1002/cphc.202000253
Surfactants worth the sacrifice : Amphiphilic and bolaamphiphilic functional hexaynes were synthesized using the Egliton-Galbraith reaction and a sacrificial monomer. The novel carbon-rich surfactants form aggregates in water, monolayers on surfaces, and stabilize the liquid-liquid interface.
[Full Papers]
Enzo Bomal, Dr. Vincent Croué, Dr. Reuben Yeo, Dr. Rosario Scopelliti, Prof. Holger Frauenrath
doi.org/10.1002/chem.201904890
1D matters ! Low-band-gap chromophores that self-assemble into one-dimensional helical nanowires show light-induced formation of polarons with unusual lifetimes exceeding hours. The accumulation of these charge carriers at concentrations close to that of the metal-insulator transition is reflected by profound macroscopic charge-transport properties and photoconductivity in these confined organic semiconductor systems.
[Full Papers]
Dr. Regina J. Hafner, Dr. Daniel Görl, Dr. Andrzej Sienkiewicz, Dr. Sandor Balog, Prof. Holger Frauenrath
doi.org/10.1002/chem.201904561
Conformer conundrum : The histidine methyltransferase EgtD produces N-α-trimethylhistidine as the first intermediate of ergothioneine biosynthesis in M. tuberculosis . This enzyme can be regulated by kinase-mediated phosphorylation. However, in vitro characterization of this process suggests that folded EgtD is a poor substrate for protein kinase D (PknD).
[Communications]
Alice Maurer, Prof. Dr. Florian P. Seebeck
doi.org/10.1002/cbic.202000232
Surfactant-free Pt nanoparticles : The careful consideration of the reducing properties of simple solvents like methanol or ethanol are key to control the growth mechanisms, stability and redispersion properties of colloidal surfactant-free Pt nanoparticles. The results provide guidelines to rationally select solvents in surfactant-free syntheses for fundamental and applied research.
[Full Papers]
Dr. Jonathan Quinson, Dr. Sarah Neumann, Laura Kacenauskaite, Dr. Jan Bucher, Prof. Dr. Jacob J. K. Kirkensgaard, Prof. Dr. Søren B. Simonsen, Prof. Dr. Luise Theil Kuhn, Alessandro Zana, Prof. Dr. Tom Vosch, Prof. Dr. Mehtap Oezaslan, Dr. Sebastian Kunz, Prof. Dr. Matthias Arenz
doi.org/10.1002/chem.202001553
The metamorphosis of organozinc reagents ! Transforming neutral R2Zn into nucleophilic R4ZnLi2 zincate complexes enabled chemoselective alkylation/arylation of nitroolefins to give 1,4-addition adducts in up to 98 % yield. Structural and spectroscopic investigations confirmed the dianionic-type nature of these species and the key role of donor additives in their aggregation and structure.
[Full Papers]
Dr. Marzia Dell'Aera, Dr. Filippo Maria Perna, Dr. Paola Vitale, Dr. Angela Altomare, Prof. Alessandro Palmieri, Dr. Lewis C. H. Maddock, Leonie J. Bole, Dr. Alan R. Kennedy, Prof. Eva Hevia, Prof. Vito Capriati
doi.org/10.1002/chem.202001294
Metamorphosis has always been the greatest symbol of change for everyone ! By transforming dialkylzincs (R2Zn) into tetraorganozincates (R4ZnLi2), a transition metal-catalyst- and ligand-free conjugate addition to nitroolefins becomes feasible en route to valuable nitroalkanes with a broad substrate scope, high chemoselectivity, and functional group tolerance within a 30 min reaction time and with no additional solvents. More information can be found in the Full Paper by E. Hevia, V. Capriati, et al. (DOI: 10.1002/chem.202001521).
[Cover Pictures]
Dr. Marzia Dell'Aera, Dr. Filippo Maria Perna, Dr. Paola Vitale, Dr. Angela Altomare, Prof. Alessandro Palmieri, Dr. Lewis C. H. Maddock, Leonie J. Bole, Dr. Alan R. Kennedy, Prof. Eva Hevia, Prof. Vito Capriati
doi.org/10.1002/chem.202001521
Curious cats : Asymmetric hydrogenation of simple olefins was achieved by using monohydride-dichloro rhodium(III) complexes 1 a -c which were characterized by NMR spectroscopy, including DOSY NMR, and X-ray single crystal analysis. Among these three complexes, 1 c has a rigid pocket surrounded by two chloride atoms bound to the rhodium atom for fitting to simple olefins without any coordinating functional groups.
[Full Papers]
Dr. Kosuke Higashida, Fabian Brüning, Nagataka Tsujimoto, Kenya Higashihara, Dr. Haruki Nagae, Prof. Dr. Antonio Togni, Prof. Dr. Kazushi Mashima
doi.org/10.1002/chem.202000542
Monohydride-dichloro rhodium(III) complexes bearing chiral diphosphine ligands stand as novel candidates for asymmetric hydrogenation of non-functionalized olefins. The sterically hindered chiral diphosphine ligand, (S)-DTBM-SEGPHOS, made it possible to isolate the rhodium(III) complex as a mononuclear complex which was confirmed by XRD analysis and DOSY NMR analysis. The novel monohydride rhodium(III) complex showed much higher enantioselectivity than classical dihydride rhodium systems on asymmetric hydrogenation of non-functionalized olefins. More information can be found in the Full Paper by A. Togni, K. Mashima, et al. (DOI: 10.1002/chem.202000542).
[Cover Pictures]
Dr. Kosuke Higashida, Fabian Brüning, Nagataka Tsujimoto, Kenya Higashihara, Dr. Haruki Nagae, Prof. Dr. Antonio Togni, Prof. Dr. Kazushi Mashima
doi.org/10.1002/chem.202001528
JoyaPhos : A new atropisomeric monophosphine (JoyaPhos) was prepared by the sequential de novo introduction of aromatic units, resulting in a configurationally stable teraryl structure with a well-defined topology. The ligand scaffold differs from canonical binaphthyl structures and can accommodate transition metals in a dense ligand sphere, suitable for stereoselective transformations.
[Communications]
Alessandro Castrogiovanni, Dr. Dominik Lotter, Fabian R. Bissegger, Prof. Dr. Christof Sparr
doi.org/10.1002/chem.202001269
The (para)site for treatment : Thirteen coumarin-diruthenium(II)⋅arene conjugates were evaluated against a transgenic T. gondii strain grown in human foreskin fibroblasts (HFF). The IC50 values ranged from 105 to 735 nM, with nine compounds displaying a lower IC50 than the standard drug pyrimethamine. TEM of T. gondii-infected HFF showed that treatment predominantly affected the parasites’ mitochondrion.
[Full Papers]
Oksana Desiatkina, Emilia Păunescu, Martin Mösching, Nicoleta Anghel, Ghalia Boubaker, Yosra Amdouni, Andrew Hemphill, Dr. Julien Furrer
doi.org/10.1002/cbic.202000174
Green & versatile : Employing a chelating agent to enable compatible water solubility of diverse metal cations affords a method to fabricate diverse n- and p-type semiconducting metal oxide photoelectrodes. A remarkable improvement in transparency for BiVO4 photoanodes (important for tandem cell operation) is quantified by the direct transmittance at 600 nm of >80 % versus the <10 % observed with the state-of-the-art material.
[Full Papers]
Dr. Charles R. Lhermitte, Annalisa Polo, Dr. Liang Yao, Dr. Florent A. Boudoire, Dr. Nestor Guijarro, Prof. Dr. Kevin Sivula
doi.org/10.1002/cssc.202000926
Catalysis in water : A sustainable catalytic process for the conversion of sugars into sugar acids using water as solvent without additives.
[Full Papers]
Andres Mollar-Cuni, Dr. Joseph P. Byrne, Dr. Pilar Borja, Dr. Cristian Vicent, Prof. Martin Albrecht, Dr. Jose A. Mata
doi.org/10.1002/cctc.202000544
Supramolecular polymers formed from phosphodiester-bridged phenanthrene trimers are doped with charged and uncharged acceptor chromophores. Excitation of the phenanthrenes is followed by efficient energy transfer to the acceptor molecules.
[Communications]
Jovana Jevric, Dr. Simon M. Langenegger, Dr. Robert Häner
doi.org/10.1002/ejoc.202000441
To elucidate the key structural features underlying the specific inhibitory activity of WOBE437, we conducted a comprehensive SAR study on almost 80 WOBE437 analogues. Several variants exhibited potencies in the sub-100 nM range and were highly selective over inhibition of the endocannabinoid-degrading fatty acid amide hydrolase. However, none of the analogues surpassed the potency of WOBE437.
[Full Papers]
Dr. Patrick Mäder, Dr. Ruben Bartholomäus, Dr. Simon Nicolussi, Alice Baumann, Melanie Weis, Dr. Andrea Chicca, Dr. Mark Rau, Dr. Ana Catarina Simão, Prof. Dr. Jürg Gertsch, Prof. Dr. Karl-Heinz Altmann
doi.org/10.1002/cmdc.202000153
Unlimited : Current research on artificial enzymes conclusively shows that we are not limited to nature's biocatalytic repertoire. Functional xenobiology, that is, the implementation of new-to-nature reactions in vivo, will open up a plethora of novel applications and has the potential for transformative biotechnological innovation. Herein, we highlight current challenges and future opportunities for xenobiotic reactions in living cells.
[Minireviews]
Tobias Vornholt, Dr. Markus Jeschek
doi.org/10.1002/cbic.202000121
Around the clock : A cationic polyelectrolyte is assembled with temporal control by means of the formaldehyde-sulfite clock reaction. Electrostatic interactions template microscopic complexes, which are then crosslinked covalently to lock-in a preformed structure. The final particle size can be controlled simply by tuning either the concentrations of components, or the initial pH value.
[Full Papers]
Christian C M. Sproncken, Dr. Berta Gumí-Audenis, Dr. Guido Panzarasa, Prof. Dr. Ilja K. Voets
doi.org/10.1002/syst.202000005
Room for independent folding . A surface display method employs the SpyCatcher-SpyTag system for post-translational in situ coupling of independently expressed and properly folded passenger enzymes and membrane anchors. The efficient surface display of delicate and complex enzymes expands the toolbox for the fabrication of productive whole-cell biocatalysts.
[Communications]
Sabrina Gallus, Dr. Theo Peschke, Dr. Malte Paulsen, Dr. Teresa Burgahn, Prof. Christof M. Niemeyer, Dr. Kersten S. Rabe
doi.org/10.1002/cbic.202000102
The road less traveled : Palladium-catalyzed hydrogenolysis of 4-O-5 diaryl ether lignin model compounds gives unexpected rearrangement monomer products. A mechanistic study indicates the cleavage of the diaryl ether bonds in lignin does not undergo a conventional solvolysis pathway but a Pd-coordinated pathway. The bond cleavage is affected by the presence of phenolic groups in the lignin.
[Full Papers]
Dr. Yanding Li, Dr. Steven D. Karlen, Dr. Benginur Demir, Dr. Hoon Kim, Prof. Jeremy Luterbacher, Prof. James A. Dumesic, Prof. Shannon S. Stahl, Prof. John Ralph
doi.org/10.1002/cssc.202000753
[Meet the Board]
Prof. Dr. Christian G. Bochet
doi.org/10.1002/cptc.202000052
Fluorescent pH-sensitive probes have been trapped in the lumen of liposomes. The sensor is linked to a DNA oligomer that is complementary to a second oligomer with a lipophilic moiety to anchor the DNA conjugate to the inner and outer leaflets of the lipid bilayer. The DNA scaffold allows subsequent selective removal of the probe in the outer bilayer leaflet.
[Full Papers]
Nicolas Dolder, Prof. Dr. Christoph von Ballmoos
doi.org/10.1002/cbic.202000146