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[ASAP] Photo-on-Demand In Situ One-Pot Synthesis of Carbonate Esters from Tetrachloroethylene
[ASAP] Total Syntheses of Phleghenrines A and C
[ASAP] Descriptors Affecting Methane Selectivity in CO2 Hydrogenation over Unpromoted Bulk Iron(III)-Based Catalysts
Confinement synthesis in porous molecule-based materials: a new opportunity for ultrafine nanostructures
DOI: 10.1039/D1SC05983A, Review Article
The space-, coordination-, and/or ion-confinement in porous molecule-based materials (PMMs) endow the PMM-confinement (pyrolysis) synthesis to construct a variety of ultrafine nanostructures.
The content of this RSS Feed (c) The Royal Society of Chemistry
[ASAP] Cu-Catalyzed Cross-Coupling of Nitroarenes with Aryl Boronic Acids to Construct Diarylamines
Construction of Hybrid Bi‐microcompartments with Exocytosis‐Inspired Behavior toward Fast Temperature‐Modulated Transportation of Living Organisms
The exocytosis-inspired behaviour was demonstrated in a temperature sensitive hybrid bi-microcompartment system. Due to the universal loading capacity and excellent biocompatibility, the proliferation and temperature-programmed fast release of living cells were realized, which provided a robust platform for the on-demand transportation of various living organisms.
Abstract
Inspired by the unique characteristics of living cells, the creation of life-inspired functional ensembles is a rapidly expanding research topic, enabling transformative applications in various disciplines. Herein, we report a facile method for the fabrication of phospholipid and block copolymer hybrid bi-microcompartments via spontaneous asymmetric assembly at the water/tributyrin interface, whereby the temperature-mediated dewetting of the inner microcompartments allowed for exocytosis to occur in the constructed system. The exocytosis location and commencement time could be controlled by the buoyancy of the inner microcompartment and temperature, respectively. Furthermore, the constructed bi-microcompartments showed excellent biocompatibility and a universal loading capacity toward cargoes of widely ranging sizes; thus, the proliferation and temperature-programmed transportation of living organisms was achieved. Our results highlight opportunities for the development of complex mesoscale dynamic ensembles with life-inspired behaviors and provide a novel platform for on-demand transport of various living organisms.
C(sp3)-H methylation enabled by peroxide photosensitization and Ni-mediated radical coupling
The "magic methyl" effect describes the change in potency, selectivity, and/or metabolic stability of a drug candidate associated with addition of a single methyl group. We report a synthetic method that enables direct methylation of C(sp3)–H bonds in diverse drug-like molecules and pharmaceutical building blocks. Visible light–initiated triplet energy transfer promotes homolysis of the O–O bond in di-tert-butyl or dicumyl peroxide under mild conditions. The resulting alkoxyl radicals undergo divergent reactivity, either hydrogen-atom transfer from a substrate C–H bond or generation of a methyl radical via β-methyl scission. The relative rates of these steps may be tuned by varying the reaction conditions or peroxide substituents to optimize the yield of methylated product arising from nickel-mediated cross-coupling of substrate and methyl radicals.
[ASAP] Methane C–H Activation by [Cu2O]2+ and [Cu3O3]2+ in Copper-Exchanged Zeolites: Computational Analysis of Redox Chemistry and X-ray Absorption Spectroscopy
[ASAP] Selective Construction of Diverse Polycyclic Spirooxindoles via a Three-Component Reaction of Cyclic Mercapto-Substituted β-Enamino Esters, Isatins, and Cyclic 1,3-Diketones
[ASAP] Pd(II)-Catalyzed Enantioselective ?-C(sp3)–H Functionalizations of Free Cyclopropylmethylamines
Cycling between Molybdenum‐Dinitrogen and ‐Nitride Complexes to Support the Reaction Pathway for Catalytic Formation of Ammonia from Dinitrogen
Cycling between molybdenum(I)‐dinitrogen and molybdenum(IV)‐nitride complexes was investigated under ambient reaction conditions. A kinetic study of the second‐order reaction rate for the conversion of the molybdenum‐dinitrogen complex into the molybdenum‐nitride complex indicates that the formation of the dinitrogen‐bridged dimolybdenum complex is involved in the rate‐determining step. A new modified reaction pathway has been proposed based on the findings of our experimental and theoretical results.
Abstract
Cycling between molybdenum(I)‐dinitrogen and molybdenum(IV)‐nitride complexes was investigated under ambient reaction conditions. A kinetic study of the second‐order reaction rate for the conversion of the molybdenum‐dinitrogen complex into the molybdenum‐nitride complex indicates that the formation of the dinitrogen‐bridged dimolybdenum complex is involved in the rate‐determining step. DFT calculations indicate that the molybdenum‐dinitrogen complex transforms into the molybdenum‐nitride complex via direct cleavage of the nitrogen‐nitrogen triple bond of the bridging dinitrogen ligand of the dinitrogen‐bridged dimolybdenum complex. The corresponding reaction of the molybdenum‐nitride complex transforming into the molybdenum‐dinitrogen complex proceeds via the ligand exchange of ammonia for dinitrogen at the dinitrogen‐bridged dimolybdenum complexes. A new modified reaction pathway has been proposed based on the findings of our experimental and theoretical results.
[ASAP] Probing Al Distribution in LiCo0.96Al0.04O2 Materials Using 7Li, 27Al, and 59Co MAS NMR Combined with Synchrotron X-ray Diffraction
Temperature-dependent polarization in a non-polar crystal
Nature, Published online: 18 November 2019; doi:10.1038/d41586-019-03494-4
A crystal’s surface has been found to behave as a distinct material that has temperature-dependent electrical polarization — despite the rest of the crystal being non-polar.Ni-catalyzed cross-electrophile coupling between vinyl/aryl and alkyl sulfonates: synthesis of cycloalkenes and modification of peptides
DOI: 10.1039/C9SC03347E, Edge Article
We report a reductive coupling between C–O electrophiles, providing an efficient approach to the synthesis of aliphatic cycloalkenes and late-stage modification of peptides.
The content of this RSS Feed (c) The Royal Society of Chemistry
Organocopper cross-coupling reaction for C–C bond formation on highly sterically hindered structures
DOI: 10.1039/C9SC00891H, Edge Article
A potent cross-coupling methodology that enables efficient carbon–carbon bond formation at sterically hindered sp2- and sp3-carbons has been developed.
The content of this RSS Feed (c) The Royal Society of Chemistry
[ASAP] Generic Ion Chromatography–Conductivity Detection Method for Analysis of Palladium Scavengers in New Drug Substances
[ASAP] Development of a Terpene Feedstock-Based Oxidative Synthetic Approach to the Illicium Sesquiterpenes
[ASAP] Graphene Nanoribbons Derived from Zigzag Edge-Encased Poly(para-2,9-dibenzo[bc,kl]coronenylene) Polymer Chains
Dynamic Kinetic Resolution of Aldehydes by Hydroacylation
Dynamic duo: Racemic α‐allyl aldehydes undergo stereoconvergent hydroacylation to generate α,γ‐disubstituted cyclopentanones with high diastereo‐ and enantioselectivities. In this dynamic kinetic resolution, a primary amine catalyst racemizes the aldehyde substrate via enamine formation and hydrolysis while a rhodium catalyst promotes cyclization.
Abstract
We report a dynamic kinetic resolution (DKR) of chiral 4‐pentenals by olefin hydroacylation. A primary amine racemizes the aldehyde substrate via enamine formation and hydrolysis. Then, a cationic rhodium catalyst promotes hydroacylation to generate α,γ‐disubstituted cyclopentanones with high enantio‐ and diastereoselectivities.
Bifluoride Ion Mediated SuFEx Trifluoromethylation of Sulfonyl Fluorides and Iminosulfur Oxydifluorides
An expedient SuFEx trifluoromethylation of sulfonyl fluorides and iminosulfur oxyfluorides is described. The efficient S−F exchange with TMSCF3 is initiated by sub‐stoichiometric quantities of bifluoride ion [FHF]− in anhydrous DMSO. The selective anticancer properties of previously inaccessible bis(trifluoromethyl)sulfur oxyimines are also demonstrated.
Abstract
SuFEx is a new‐generation click chemistry transformation that exploits the unique properties of S−F bonds and their ability to undergo near‐perfect reactions with nucleophiles. We report here the first SuFEx‐based procedure for the efficient synthesis of pharmaceutically important triflones and bis(trifluoromethyl)sulfur oxyimines from sulfonyl fluorides and iminosulfur oxydifluorides, respectively. The new process involves rapid S−F exchange with trifluoromethyltrimethylsilane (TMSCF3) upon activation by potassium bifluoride in anhydrous DMSO. The reaction tolerates a wide selection of substrates and proceeds under mild conditions without need for chromatographic purification. A tentative mechanism is proposed involving nucleophilic displacement of S−F by the trifluoromethyl anion via a five‐coordinate intermediate. The utility of late‐stage SuFEx trifluoromethylation is demonstrated through the synthesis and selective anticancer properties of a bis(trifluoromethyl)sulfur oxyimine.
New Platforms for Stable Carbon‐Centered Radicals
Organic radicals can play important roles potentially in diverse functional materials owing to an unpaired electron but are usually highly reactive and difficult to use. Therefore, stabilization of organic radicals is crucially important. Among organic radicals, carbon‐centered radicals are promising because of their trivalent nature that enables structural diversity and elaborate designs but they show less stabilities because of reactivities toward carbon‐carbon bond formation and atmospheric oxygen. Recently, stable carbon‐centered radicals have been increasingly explored on the basis of diverse molecular platforms. This minireview highlights these newly explored stable carbon‐centered radicals with a particular focus on porphyrinoid‐stabilized radicals owing to their remarkable spin delocalization abilities.
[ASAP] Synthesis, Structures, and Magnetic Properties of Two Coordination Assemblies of Mn(III) Single Molecule Magnets Bridged via Photochromic Diarylethene Ligands
[ASAP] Solid-State Order and Charge Mobility in [5]- to [12]Cycloparaphenylenes
Intertwined Titanium Carbide MXene within a 3 D Tangled Polypyrrole Nanowires Matrix for Enhanced Supercapacitor Performances
Electrode architecture: Intertwined titanium carbide MXene within a tangled polypyrrole nanowire matrix is prepared and demonstrated as a novel hybridization electrode with outstanding gravimetric capacitance (610 F g−1) and stability (14 000 cycles) compared with reported MXene‐based supercapacitors (see figure).
Abstract
The exploration of the rational design and synthesis of unique and robust architectured electrodes for the high capacitance, rate capability, and stability of supercapacitors is crucial to the future of energy storage technology. Herein, an in situ synthesis of multilayered titanium carbide MXene tightly caging within a 3 D conducting tangled polypyrrole (PPy) nanowire (NW) network is proposed as an effective strategy to prevent the aggregation of MXene, profoundly enhancing the electrochemical performance of the supercapacitor. Owing to the beneficial effects of an ideal 3 D interconnected porous structure and high electrical conductivity, the obtained electrode exhibits fast charge and ion transport kinetics as well as full usage of active material. As expected, the 3 D Ti3C2T x @PPY NW exhibits a specific capacitance five times higher than that of pristine MXene (610 F g−1), a good rate capability up to a current density of 25 A g−1, and excellent stability with 100 % retention after 14 000 cycles at 4 A g−1, outperforming the known state‐of‐the‐art MXene‐based supercapacitor. Our work provides a facile method for enhancing the performance of MXene‐based energy storage devices.
Catalytic enantioselective Minisci-type addition to heteroarenes
Basic heteroarenes are a ubiquitous feature of pharmaceuticals and bioactive molecules, and Minisci-type additions of radical nucleophiles are a leading method for their elaboration. Despite many Minisci-type protocols that result in the formation of stereocenters, exerting control over the absolute stereochemistry at these centers remains an unmet challenge. We report a process for addition of prochiral radicals, generated from amino acid derivatives, to pyridines and quinolines. Our method offers excellent control of both enantioselectivity and regioselectivity. An enantiopure chiral Brønsted acid catalyst serves both to activate the substrate and induce asymmetry, while an iridium photocatalyst mediates the required electron transfer processes. We anticipate that this method will expedite access to enantioenriched small-molecule building blocks bearing versatile basic heterocycles.