Construction of defined nanostructures is a key for enhancing the efficiency of heterogeneous catalytic materials. However, for metal‐free, organic conjugated polymer‐based photocatalysts, due to their mostly amorphous nature or specific synthetic routes, synthesis of defined nanostructures is still highly challenging. Here, we report the formation of covalent triazine framework (CTF) nanoparticles via a size‐controllable confined polymerization strategy. The uniform CTF nanoparticles exhibited significantly...
Wed Jul 22, 2020 22:00
Strain‐promoted azide‐alkyne cycloaddition using dibenzoazacyclooctyne (DBCO) is widely applied in copper‐free bioorthogonal reactions. Here, we report the efficient acid‐promoted rearrangement and silver‐catalyzed amidation of DBCO, which alters its click reactivity robustly. In the switched click reaction, DBCO, as a caged acylation reagent, enables rapid peptide/protein modification after decaged by silver catalysts that renders site‐specific conjugation of IgG antibody via an Fc‐targeting peptide.
Wed Jul 22, 2020 19:16
Device simplification is of practical significance for organic light emitting diodes (OLEDs), which remains the great challenge for deep‐red emitters because of their narrow bandgap worsened nonradiation. Herein, a deep‐red thermally activated delayed fluorescence molecule ( p TPA‐DPPZ ) is reported with the feature of the T shape structure containing two triphenylamine (TPA) donors substituted at both sides of planar dipyridophenazine (DPPZ) acceptor. The rational spatial arrangement of the functional...
Wed Jul 22, 2020 19:09
The key to fully leveraging the potential of electrochemical CO2 reduction reaction (CO2RR) to achieve a sustainable solar power‐based economy is the development of high‐performance electrocatalysts. The development process relies heavily on trial and error methods due to poor mechanistic understanding of the reaction. Here we demonstrate that ionic liquids (ILs) can be employed as a chemical trapping agent to probe CO2RR mechanistic pathways. This method is implemented by introducing a small amount...
Wed Jul 22, 2020 18:13
Single‐atom catalysts (SACs) have been successfully used for various electrochemical reactions. The synthetic methods for different single metal atoms are specific, however; it is extremely challenging to develop a universal synthesis method for a large range of single‐atom metals. Herein, we report a comprehensive strategy to synthesize a full range of single‐atom metals on carbon matrix, including vanadium (V1), manganese (Mn1), iron (Fe1), cobalt (Co1), nickel (Ni1), copper (Cu1), germanium (Ge1),...
Wed Jul 22, 2020 17:41
Signal transduction in living systems is the conversion of information into a chemical change and the principal process by which cells communicate. This process enables phenomena as time‐keeping and signal amplification. In nature, these functions are encoded in non‐equilibrium (bio)chemical reaction networks (CRNs) controlled by enzymes, as integral part of biocatalytic pathways. Yet, man‐made catalytically controlled networks are rare. Here, we incorporate catalysis in an artificial fuel‐driven...
Wed Jul 22, 2020 16:46
The ability to modify peptides and proteins chemoselectively is of continued interest in medicinal chemistry, with peptide conjugation, lipidation, stapling and disulfide engineering at the forefront of modern peptide chemistry. Herein we report a robust method for the on‐resin preparation of allenamide‐modified peptides, an unexplored functionality for peptides that provides a versatile chemical tool for chemoselective inter‐ or intramolecular bridging reactions with thiols. The bridging reaction...
Wed Jul 22, 2020 16:44
Regiodivergent C–H and C–C Alkylation by Ruthenium Catalysis: ortho versus meta Position‐Selectivity
Ruthenium(II)biscarboxylate complexes enabled the selective alkylation of C–H and C–C bonds at the ortho ‐ or meta ‐position. ortho ‐C–H Alkylations were achieved with 4‐, 5‐ as well as 6‐membered halocycloalkanes. Furthermore, the judicious choice of the directing group allowed for a full control of ortho‐/meta ‐selectivities. Detailed mechanistic studies by experiment and computation were performed and provided strong support for a homolytic C–X cleavage.
Wed Jul 22, 2020 16:44
Amplified spontaneous emission (ASE) is intrinsically associated with lasing applications. Inefficient photon energy transfer to ASE is a long‐standing issue for organic semiconductors that consist of multiple competing radiative decay pathways, far from being rationally regulated from the perspective of molecular arrangements. Herein, we achieve controllable molecular packing motifs by halogen‐bonded cocrystallization, leading to ten times increased radiative decay rate, four times larger ASE radiative...
Wed Jul 22, 2020 16:40
Acetylene removal from ethylene is a crucial step in the production of polymer‐grade ethylene, but remains as a daunting challenge due to the similar physicochemical properties between acetylene and ethylene, and is currently met industrially by energy‐intensive cryogenic distillation processes. Herein, we report a robust ultramicroporous metal‐organic framework (MOF), Ni3(pzdc)2(7Hade)2 for efficient C2H2/C2H4 separation. Interestingly, this MOF is constructed by hydrogen‐bonding linked one‐dimensional...
Wed Jul 22, 2020 16:15
Mitigating ambient nitrogen dioxide (NO 2 ) pollution via selective adsorption on porous materials represents a promising approach to tackle such an increasingly pressing environmental health issue. However, very few porous adsorbents have sufficiently high NO 2 adsorption capacity and good regenerability simultaneously. Here we attempt to address this challenge by developing π‐backbonding adsorbents in the transition metal (TM) incorporated porphyrin metal‐organic frameworks (PMOFs). Breakthrough...
Wed Jul 22, 2020 16:09
Pick and choose : Ir catalysis enables, for the first time, the synthesis of diversely protected allenylic amines employing readily available ammonia equivalents. This convenient method is scalable and with access to these building blocks in high enantiomeric excess, a variety of optically active heterocycles may be prepared which incorporate commonly used amine protecting groups. Abstract The first iridium catalyzed, enantioconvergent amination of allenylic carbonates is reported. This...
Wed Jul 22, 2020 15:04
In molecular design , structural, pharmacological and chemical information can be interconnected by computational estimations of binding free energies. Using a combined FEP approach to examine both mutagenesis and ligand SAR, we designed new analogues of the A2AAR antagonist series of chromones. Subsequent crystal structures supported the rational design of these compounds, linking the structural and energetic understanding on ligand binding. Abstract We present a robust protocol based...
Wed Jul 22, 2020 14:51
Nitrogen‐doped graphene quantum dots (NGQ) on a CuO‐derived‐Cu nanorod (NGQ/Cu‐nr) are used for the electrocatalytic reduction of CO2 to ethanol and n‐propanol. The Faradaic efficiency of C2+ alcohols could reach 52.4 % with a total current density of 282.1 mA cm−2. NGQ/Cu‐nr can provide dual active sites and stabilize oxygenic C2 intermediates, resulting in a great improvement in the reduction of CO2 to alcohols. Abstract Electroreduction of CO2 to liquid fuels such as ethanol and n‐propanol,...
Wed Jul 22, 2020 14:50
Diels‐Alder reactions are established as one of the most effective ways to prepare stereochemically complex 6‐membered rings. Different catalysis concepts have been reported including dienophile activation by Lewis acids or H‐bond donors and diene activation by bases. Here we report a new concept, in which an acidic prodiene is acidified by a Lewis acid to facilitate deprotonation by an imidazolium‐aryloxide entity within a polyfunctional catalyst. A metal dienolate is thus formed, while imidazolium‐ArOH...
Wed Jul 22, 2020 14:39
Catalyst‐free addition of ketone enolate to non‐activated multiple C‐C bonds involves non‐complementary reaction partners and typically requires super‐basic conditions. On the other hand, highly aggregated or solvated enolates are not reactive enough to undergo direct addition to alkenes or alkynes. Herein, we report a new anionic cascade reaction for one‐step assembly of intriguing molecular scaffolds possessing contiguous six‐, five‐ and four‐membered rings, representing a formal [2+2] enol‐allene...
Wed Jul 22, 2020 13:40
Confining nanostructured electrode materials in porous carbon represents an effective strategy for improving the electrochemical performance of lithium‐ion batteries. Herein, we report the elaborate design and synthesis of hybrid hollow nanostructures composed of highly dispersed Co 3 O 4 hollow nanoparticles (sub‐20 nm) embedded in the mesoporous walls of carbon nanoboxes (denoted as H‐Co 3 O 4 @MCNBs) as an anode material for lithium‐ion batteries. The facile metal‐organic framework...
Wed Jul 22, 2020 12:11
Electrophile‐induced stereospecific 1,2‐migration of boronate complexes has been successfully applied in many asymmetric reactions. Typically, the electrophilic species provides the activation required for the boronate complex to undergo the desired migration of a group from boron to the adjacent sp2 or sp3‐hybridized carbon. Such activating species range from stoichiometric classical electrophiles to transition metal complexes present in catalytic quantities. Abstract The stereospecific...
Wed Jul 22, 2020 11:47
We here report the synthesis of a new tetraborylethylene (TBE) and its application in the preparation of [4+0]‐tetraarylethenes (TAEs) that have widespread applications in material science and supramolecular chemistry due to their aggregation‐induced emission (AIE) nature. The divergent and stereoselective synthesis of [3+1]‐, [2+2]‐, [2+1+1]‐TAEs via multi‐couplings of vinylboronates with aryl bromides were also demonstrated. These couplings feature broad substrate scope and excellent functional...
Wed Jul 22, 2020 12:21
Through‐space charge transfer polynorbornenes with fixed and controllable spatial alignment of donor and acceptor in edge‐to‐face/face‐to‐face stacking patterns are developed for achieving high‐efficiency blue thermally activated delayed fluorescence (TADF). The alignment is realized by two aspects of molecular engineering on stereo‐configuration of polymer skeleton and topological architecture of donor, including (i) using cis, exo‐configuration of norbornene to confine donor and acceptor in close...
Wed Jul 22, 2020 12:21
I of the tiger : The iodine atom in Ar−I bonds is commonly conceived as a leaving group. This Minireview discusses a powerful alternative reactivity of iodine substituents by which λ3‐iodoarenes direct C−H coupling events at the corresponding aromatic ring. Abstract Hypervalent organoiodane reagents are ubiquitous in organic synthesis, both as oxidants and as electrophilic group‐transfer agents. In addition to these hallmark applications, a complementary strategy is gaining momentum that...
Tue Jul 21, 2020 21:44
We have synthesized a complete new family of acyclic trimeric cyclodiphosphazanes compounds comprising NH, N i Pr, N t Bu and NPh bridging groups. In addition, the first NH‐bridged acyclic dimeric cyclophosphazane has been also produced. The trimeric species display highly tuneable characteristics whereby the distance between the terminal N(H)R moieties can be readily modulated by the steric bulk present in the bridging groups (ranging from ~6 to ~10 Å). Moreover, these species exhibit pronounced...
Tue Jul 21, 2020 21:40
A divergent synthetic approach to biogenetically related diterpenoids such as ent ‐kauranes, ent ‐trachylobanes, ent ‐beyerane, and ent ‐atisane has been developed. The unified synthetic route involves the De Mayo reaction to rapidly generate the bicyclo[3.2.1]‐octane moiety of ent ‐kaurane. The key reactions also include bioinspired nucleophilic cyclopropanation generating the [3.2.1.0 2,7 ]‐tricyclic core of ent ‐trachylobane and regioselective cyclopropane fragmentation furnishing...
Tue Jul 21, 2020 19:10
Benzene hydrogenation is one of important industrial processes. The reaction is incomplete, resulting in a mixture of benzene, cyclohexane and/or cyclohexene which have to be separated before the following reactions. The currently‐used extractive and azeotropic distillations are operationally complex and energy‐intensive. Adsorptive separation provides an alternative energy‐efficient method. However, the separation of the ternary mixture has not been reported with adsorptive separation. In the present...
Tue Jul 21, 2020 19:10
A straightforward alkali‐metal‐mediated protocol for hydroamination of styrenes using biorenewable 2‑methyltetrahydrofuran as a solvent is reported. Refuting the conventional wisdom of the incompatibility of organolithium reagents with air and moisture, we show that the presence of moisture is key in favouring formation of the target phenethylamines over competing olefin polymerisation products. The method is also compatible with sodium amides, with the latter showing excellent promise as highly...
Tue Jul 21, 2020 17:09
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