Exploring the Functional Consequences of Protein Backbone Alteration in Ubiquitin through Native Chemical Ligation

A modular synthetic route based on native chemical ligation enables the systematic examination of folding and function in variants of the protein ubiquitin with altered chemical composition of the polypeptide backbone.

[Communications]
Dr. Halina M. Werner, Samuel K. Estabrooks, Dr. G. Michael Preston, Prof. Dr. Jeffrey L. Brodsky, Prof. Dr. W. Seth Horne
doi.org/10.1002/cbic.201900225

Minimalist Protocell Design: A Molecular System Based Solely on Proteins that Form Dynamic Vesicular Membranes Embedding Enzymatic Functions

A generalizable molecular platform for minimalist cell design: Essential features of extant cells include compartmentalization and biocatalytic activity. In this context we designed a minimal cell system in which the protocellular membrane was made up solely of protein components, by use of amphiphilic block-domain elastin-like proteins together with free or conjugated enzymes.

[Full Papers]
Dr. Matthias C. Huber, Dr. Andreas Schreiber, Dr. Stefan M. Schiller
doi.org/10.1002/cbic.201900283

Cell Fuelling and Metabolic Energy Conservation in Synthetic Cells

Energy levelled: A controlled energy supply is crucial for any synthetic cell. We have estimated the demand for ATP by polymer synthesis and maintenance processes in small cell-like systems, and we describe circuits to control the need for ATP. We also present fluorescence-based sensors that allow the major physicochemical conditions inside cells to be monitored and tuned.

[Minireviews]
Hendrik R. Sikkema, Bauke F. Gaastra, Tjeerd Pols, Bert Poolman
doi.org/10.1002/cbic.201900398

Controlling Selectivity in Alkene Oxidation: Anion Driven Epoxidation or Dihydroxylation Catalysed by [Iron(III)(Pyridine-Containing Ligand)] Complexes

Robust system: Controllable iron(III)-catalysed alkene epoxidation or dihydroxylation reactions are performed by judicious choice of anion in [Fe(III)(Pc-L)] catalysts (Pc-L=pyridine-based 12-membered tetraaza-macrocyclic ligands). The catalytic system proved its robustness by performing several catalytic cycles, without observing catalyst deactivation. The use of acetone as a solvent and hydrogen peroxide as terminal oxidant renders this catalytic system appealing.

[Full Papers]
Dr. Giorgio Tseberlidis, Luca Demonti, Dr. Valentina Pirovano, Prof. Dr. Marco Scavini, Serena Cappelli, Prof. Dr. Silvia Rizzato, Prof. Dr. Rubén Vicente, Prof. Dr. Alessandro Caselli
doi.org/10.1002/cctc.201901045

High-Voltage Performance of Ni-Rich NCA Cathodes: Linking Operating Voltage with Cathode Degradation

If I was a rich cathode: NCA lattice contraction occurs during high-voltage cycling, which may indicate the gliding of lattice planes due to atomic structural rearrangement/modification. This phenomenon may not completely destroy the material lattice structure in the first cycle. However, the extent of lattice contraction (at higher UCV) may initiate permanent altering of the host NCA structure and cause an increase in capacity fading rate at Ni-rich NCA cathodes.

[Articles]
Dr. Lamuel David, Dr. Debasish Mohanty, Dr. Linxiao Geng, Dr. Rose E. Ruther, Dr. Athena S. Sefat, Dr. Ercan Cakmak, Dr. Gabriel M. Veith, Dr. Harry M. Meyer III, Dr. Hsin Wang, Dr. David L. Wood III
doi.org/10.1002/celc.201901338

Double Phosphinoboration of CO2: A Facile Route to Diphospha-Ureas

From CO2 to urea: The reactions of CO2 with a series of phosphinoboranes afford compounds of the form R2PCO2BR′2 and diphospha-ureas, (R2P)2CO. Computational data reveals a mechanism, involving a double phosphinoboration of CO2.

[Communications]
James H. W. LaFortune, Dr. Zheng-Wang Qu, Karlee L. Bamford, Alina Trofimova, Prof. Dr. Stephen A. Westcott, Prof. Dr. Douglas W. Stephan
doi.org/10.1002/chem.201903407

Octacarbonyl Ion Complexes of Actinides [An(CO)8]+/− (An=Th, U) and the Role of f Orbitals in Metal-Ligand Bonding

Electron-counting rules for the actinide complexes: An energy decomposition analysis of the covalent metal-CO interactions in the actinide octacarbonyl cations and anions [An(CO)8]+/− (An=Th, U) reveals that the major contribution comes from the metal d AOs followed by f-orbital interactions (see picture).

[Full Papers]
Dr. Chaoxian Chi, Dr. Sudip Pan, Dr. Jiaye Jin, Dr. Luyan Meng, Prof. Mingbiao Luo, Prof. Lili Zhao, Prof. Mingfei Zhou, Prof. Gernot Frenking
doi.org/10.1002/chem.201902625

Exotic Bonding Regimes Uncovered in Excited States

Real-space tools were employed to show that the chemical bonding scenario used routinely to understand ground states lacks the required flexibility for excited states. Real-space bond orders can have previously unreported exotic values, and bond orders greater than one and negative bond orders for a single electron pair emerge in situations in which the electrons in a bonding pair show a gregarious (bosonic) instead of the usual lonely (fermionic) behavior (see figure).

[Full Papers]
Jos� Luis Casals-Sainz, Prof. Jes�s Jara-Cort�s, Prof. Jes�s Hern�ndez-Trujillo, Jos� Manuel Guevara-Vela, Prof. Evelio Francisco, Prof. �ngel Mart�n Pend�s
doi.org/10.1002/chem.201902369

Reactivity of a Sterically Unencumbered α-Borylated Phosphorus Ylide towards Small Molecules

Free to move: A sterically unencumbered α-borylated phosphorus ylide (α-BCP) Me3PC(H)B(iBu)2 (1) has been synthesized, characterized, and investigated with the aid of DFT calculations. Compound 1 reacts with various small molecules, such as NH3, CO, and CO2, and heterocumulenes PhNCX (see figure).

[Full Papers]
Michael Radius, Dr. Ewald Sattler, Helga Berberich, Prof. Dr. Frank Breher
doi.org/10.1002/chem.201902681

Identification of Phenylpyrazolone Dimers as a New Class of Anti-Trypanosoma cruzi Agents

Chagas disease is currently treated with only two drugs, benznidazole and nifurtimox, both of which show limited efficacy and certain adverse effects. In this study, phenotypic screening and subsequent optimization led to a bromophenyldihydropyrazole dimer (NPD-0228), which is inactive against the bloodstream (trypomastigote) form of T. cruzi, but shows sub-micromolar potency on the intracellular (amastigote) forms of the various parasite strains that are clinically relevant. As benznidazole is most active against the bloodstream form, NPD-0228 might be well suited to combination treatments.

[Full Papers]
Maarten Sijm, Julianna Siciliano de Araújo, Alba Ramos Llorca, Dr. Kristina Orrling, Lydia Stiny, An Matheeussen, Prof. Dr. Louis Maes, Prof. Dr. Iwan J. P. de Esch, Dr. Maria de Nazaré Correia Soeiro, Dr. Geert Jan Sterk, Prof. Dr. Rob Leurs
doi.org/10.1002/cmdc.201900370

Total Synthesis of the Endocannabinoid Uptake Inhibitor Guineensine and SAR Studies

The piperamide guineensine is a potent inhibitor of endocannabinoid uptake. We developed an efficient and scalable total synthesis of guineensine, which has also served as a platform for the synthesis of analogues with modified end groups. While modifications of the N-substituent on the amide nitrogen were generally well tolerated, the benzodioxolyl group was more sensitive to structural changes. This group may represent a specific structural requirement for inhibition of endocannabinoid uptake by guineensine and other piperamides.

[Full Papers]
Dr. Ruben Bartholomäus, Dr. Simon Nicolussi, Alice Baumann, Mark Rau, Dr. Ana Catarina Simão, Prof. Dr. Jürg Gertsch, Prof. Karl-Heinz Altmann
doi.org/10.1002/cmdc.201900390

A Focused Library of NO-Donor Compounds with Potent Antiproliferative Activity Based on Green Multicomponent Reactions

The eco-friendly synthesis via multicomponent reactions and biological evaluation of a series of novel NO donors is presented. All compounds were examined for their activity against six different solid tumor cell lines as well as against non-tumorigenic mammalian cells to investigate their selectivity. To examine the relationship between NO release and antiproliferative activity, the cytotoxic activity was evaluated in the presence of a well-known NO scavenger. Compounds 4 k and 6 d arise as candidates for further studies.

[Full Papers]
Mariana Ingold, Luc�a Colella, Dr. Paola Hern�ndez, Dr. Carlos Batthy�ny, Dr. David Tejedor, Adri�n Puerta, Dr. Fernando Garc�a-Tellado, Dr. Jos� M. Padr�n, Dr. Williams Porcal, Dr. Gloria. V. L�pez
doi.org/10.1002/cmdc.201900385

Enhanced Deep-Learning Prediction of Molecular Properties via Augmentation of Bond Topology

Toward 3D: Incorporation of bond topology to molecular-graph representation enables the handling of 3D molecules efficiently in deep learning. While outperforming state-of-the art deep-learning models in the prediction of chemical and biological properties, the 3D graph convolutional network has the ability to both generalize and distinguish the molecular rotations in 3D.

[Full Papers]
Hyeoncheol Cho, Prof. Dr. Insung S. Choi
doi.org/10.1002/cmdc.201900458

Effect of the Random Defects Generated on the Surface of Pt(111) on the Electro-oxidation of Ethanol: An Electrochemical Study

Ethanol electro-oxidation: The Pt(111) surface structure is highly uniform, ordered, stable, compact, and with a high surface atomic density. Many potential incursions above its potential stability limit are required to disorder its original surface atomic arrangement by 20 % at Pt(110) and Pt(100). A Pt(111) surface with induced mixed (110) and (100) defects showed an excellent performance for the ethanol electro-oxidation reaction, with catalytic properties greater thanthose of non-defected Pt(111).

[Articles]
Amaury F. B. Barbosa, Vinicius Del Colle, Ana M. Gómez-Marín, Camilo A. Angelucci, Dr. Germano Tremiliosi-Filho
doi.org/10.1002/cphc.201900544

π-Conjugated Molecules: From Structure to Function

Appealing properties: ChemPlusChem is proud to present its Special Issue on π-Conjugated Molecules and their Applications, guest-edited by Paolo Samorí, Xinliang Feng, and Davide Bonifazi. It contains both research and review articles that feature some of the most enlightening approaches on the synthesis of novel conjugated (macro)molecules, and highlights their special chemical and physical properties arising from the π-conjugation, as well as their processing and self-assembly at surfaces and interfaces, and integration into a range of devices.

[Editorial]
Prof. Paolo Samorí, Prof. Xinliang Feng, Prof. Davide Bonifazi
doi.org/10.1002/cplu.201900442

Computational Photochemistry

[Editorial]
Prof. Denis Jacquemin, Prof. Llu�s Blancafort, Prof. Young Min Rhee
doi.org/10.1002/cptc.201900204

Methyl Ketones from Municipal Solid Waste Blends by One-Pot Ionic-Liquid Pretreatment, Saccharification, and Fermentation

Waste not, want not: A highly efficient and sustainable one-pot process was developed for the production of biofuels through conversion of municipal solid waste blends to methyl ketones by using a bioderived ionic liquid followed by fermentation with an engineered Escherichia coli strain.

[Full Papers]
Dr. Jipeng Yan, Ling Liang, Qian He, Dr. Chenlin Li, Dr. Feng Xu, Dr. Jian Sun, Dr. Ee-Been Goh, Dr. N. V. S. N. Murthy Konda, Dr. Harry R. Beller, Dr. Blake A. Simmons, Dr. Todd R. Pray, Dr. Vicki S. Thompson, Dr. Seema Singh, Dr. Ning Sun
doi.org/10.1002/cssc.201901084

Incorporating p-Phenylene as an Electron-Donating Group into Graphitic Carbon Nitride for Efficient Charge Separation

Bridging the gaps: A facile strategy is developed for incorporating p-phenylene into graphitic carbon nitride to repair defects by bridging oligoheptazine units. The resulting localized spatial charge states on the surface of the carbon nitride facilitate the separation of photogenerated electrons and holes and thus significantly enhance the performance in the photocatalytic hydrogen evolution reaction.

[Full Papers]
Dr. Honglin Gao, Dr. Yong Guo, Zhiwu Yu, Meiming Zhao, Yang Hou, Zhongqi Zhu, Prof. Shicheng Yan, Prof. Qingju Liu, Prof. Zhigang Zou
doi.org/10.1002/cssc.201901239

Biomass-Derived Carbon: A Value-Added Journey Towards Constructing High-Energy Supercapacitors in an Asymmetric Fashion

Waste to wealth: This Review discusses the basic concepts of supercapacitors with a focus on historical background, factors that influence high-performance biomass-derived materials, and the challenges involved in fabricating asymmetric supercapacitors with high energy. This comprehensive review will also help researchers in the future to construct asymmetric supercapacitors in aqueous electrolyte with cost-effective electrodes.

[Reviews]
M. L. Divya, Dr. Subramanian Natarajan, Prof. Yun-Sung Lee, Dr. Vanchiappan Aravindan
doi.org/10.1002/cssc.201901880

Probing the Donor Properties of Pincer Ligands Using Rhodium Carbonyl Fragments: An Experimental and Computational Case Study

The spectroscopic properties of rhodium(I) and rhodium(III) carbonyl complexes of the form [Rh(pincer)(CO)][BArF4] and [Rh(pincer)Cl2(CO)][BArF4] have been critically analysed in the context of the donor strength of the constituent pincer ligands.

[Full Papers]
Gemma L. Parker, Samantha Lau, Baptiste Leforestier, Adrian B. Chaplin
doi.org/10.1002/ejic.201900727

Synthesis of a Boronic Acid Anhydride Based Ligand and Its Application in Beryllium Coordination

The synthesis of a boronic acid anhydride-based ligand and its use as a tridentate ligand in beryllium coordination chemistry is presented. The generated hetero-tri-nuclear complex enables the direct comparison of bond lengths and angles at beryllium and boron atoms in similar coordination environments.

[Full Papers]
Magnus R. Buchner, Matthias M�ller, Onyekachi Raymond, Rebecca J. Severinsen, David J. Nixon, William Henderson, Penelope J. Brothers, Gareth J. Rowlands, Paul G. Plieger
doi.org/10.1002/ejic.201900772

Synthesis of Orthogonal N-Protected C-Functional Side-Bridged Cyclams to Give Access to Unsymmetrical Constrained BCAs

A general procedure to obtain orthogonally N-protected side-bridged cyclams with a benzyl or a Boc group was developed. Such methodology is especially applicable on C-functionalized macrocycles. Despite the lack of symmetry of these compounds, this strategy allows the specific protection of one or the other remaining secondary amine function.

[Full Papers]
Thomas Le Bihan, Nathalie Le Bris, H�l�ne Bernard, Carlos Platas-Iglesias, Rapha�l Tripier
doi.org/10.1002/ejoc.201901013

Controlling Stereoselectivity in Tribromide Mediated Oxidative Dearomatisations - Synthesis of Selective Spirofurano-naphthalones

A mild and highly stereocontrolled tribromide mediated synthesis of spiro-furano naphthalones via a oxidative dearomatisation process is reported.

[Full Papers]
Debayan Sarkar, Puspendu Kuila, Devashish Sood
doi.org/10.1002/ejoc.201900974

Boryl Radical Addition to Multiple Bonds in Organic Synthesis

Recent advances in organoboron chemistry have enabled generation and reactions of boryl radicals in organic synthesis. This review summarizes addition reactions of boryl radicals to various multiple bonds, which offer easy access to novel organoboron compounds and useful chemical transformations.

[Minireview]
Tsuyoshi Taniguchi
doi.org/10.1002/ejoc.201901010