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The preparation of ferrocenes with both axial and planar chiralities poses a considerable challenge. Herein we report a new strategy for the construction of both axial and planar chiralities in a ferrocene system via palladium/chiral norbornene (Pd/NBE*) cooperative catalysis. In this fascinating domino reaction, the firstly established axial chirality is dictated by Pd/NBE* cooperative catalysis, while the latter planar chirality is controlled by the pre-installed axial chirality through a unique axial-to-planar diastereoinduction process. This method exploits readily available ortho-ferrocene-tethered aryl iodides (14 examples) and the bulky 2,6-disubstituted aryl bromides (14 examples) as the starting materials. 5- to 7-membered benzo-fused ferrocenes with both axial and planar chiralities (29 examples) are obtained in one step with constantly excellent enantioselectivities (> 99% e.e.) and diastereoselectivities (> 19:1 d.r.).

A [4+2] annulation of two different styrenes to construct polysubstituted 1,2-dihydronaphthalenes was achieved. This transformation proceeded smoothly under electrochemical oxidative conditions wit...

A sulphate functionalized Ru catalyst (Ru-SO4) with a decreased energy barrier of water formation has been constructed for effective alkaline hydrogen oxidation electrocatalysis.

We have developed a (4 + 2) radical annulation approach for the synthesis of diverse chromans. This method is complementary to the traditional Diels–Alder [4 + 2] annulation of ortho-quinone methides and electron-rich dienophiles.

We report the synthesis of nitridation-induced NiFe-MOF through post-synthetic functionalization of terminal ligand in NiFe-MOF nanosheet. We directly identify the key factor of amino ligand in N-NiFe-MOF for boosting the OER performance through combining single X-ray crystallographic characterization and in-situ Raman tracking, as well as ex-situ spectroscopy analysis. Density functional theory (DFT) calculations and experimental results indicate irreversible phase reconstruction from amino ligand oxidation prior to OER could lead to the optimized ΔG*O, resulting in the remarkable OER performance with an overpotential of 258 mV to obtain the current density of 100 mA cm−2 in 1.0 M KOH solution. Our work will provide new strategy for rational designing advanced MOF-based OER electrocatalysts.

Summary Inorganic porous materials are prevailing in energy storage, environment remediation, and catalysis; however, it is attractive to control the spatial arrangement of heterometals in these materials with atomic accuracy. Here, we report the precise positioning of metals with identical valence, coordination number, and similar size, such as Zn (II) and Co (II), to generate an alternating sequence in a multivariate (MTV) metal-organic framework (MOF), ZnCo-MTV-MOF-699, with a rare sheet secondary building unit. This is achieved by precoding their coordination number in a parent MOF, ZnCo-MOF-69C, followed by single-crystal-to-single-crystal transformation, where the entire process is monitored in situ by time-resolved small-angle X-ray scattering. Coordination number precoding of other metal pairs, Zn-Ni and Zn-Cu, in MTV-MOFs is also obtained. The sequence-coded MTV-MOF exhibits a much lower overpotential than that of the non-coded counterpart in oxygen evolution reaction, unveiling the power of metal sequence control.

The illustration of the fabrication of nanoalloys by laser nanometallurgy using multivariate MOF as precursor.

Nitroaromatics are tremendously valuable organic compounds with a long history of being used as pharmaceuticals, agrochemicals, and explosives as well as vital intermediates to a wide variety of chemicals. Consequently, the exploration of aromatic nitration has become an important endeavor in both academia and industry. Herein, we report the identification of a powerful nitrating reagent, 5-methyl-1,3-dinitro-1

Herein, we report a modular and convergent strategy for the assembly of atropisomeric o-terphenyls with 1,2-diaxes via palladium/chiral norbornene cooperative catalysis and axial-to-axial diastereoinduction. Readily available aryl iodides, 2,6-substituted aryl bromides, and potassium aryl trifluoroborates are used as the building blocks, laying the foundation for diversity-oriented synthesis of these scaffolds (46 examples). Other features include the unique axial-to-axial diastereoinduction mode, construction of two axes in a single operation, and step economy. DFT calculations are performed to rationalize the axial-to-axial diastereoinduction process. Synthetic utilities of this method in preparation of atropisomeric oligophenyls, chiral catalysts, and ligands are demonstrated.

Construction of eight-membered silacycles via Pd-catalyzed (4 + 4) annulation of silacyclobutanes and 2-iodobiphenyl derivatives is described. This strategy involves direct C–H and C–Si bond activa...

Transition metal-based electrocatalysts will undergo surface reconstruction to form active oxyhydroxide-based hybrids, which are regarded as the "true-catalysts" for the oxygen evolution reaction (OER). Much effort has been devoted to understanding the surface reconstruction, but little on identifying the origin of the enhanced performance derived from the substrate effect. Herein, we report the electrochemical synthesis of amorphous CoOOH layers on the surface of various cobalt sulfides (CoS

1,3-trans-Disubstituted tetrahydroisoquinoline (THIQ) is a common heterocyclic structural unit of naphthylisoquinoline alkaloids. The assembly of this structural unit is not trivial, which constitutes a substantial challenge in the total synthesis of naphthylisoquinoline alkaloids and related pharmaceuticals. Herein, we report a modular and convergent method for the rapid assembly of 1,3-trans-disubstituted THIQ frameworks through a three-component Catellani reaction and a Au

Layered transition metal dichalcogenide (TMD) nanomaterials are promising alternatives to platinum (Pt) for the hydrogen evolution reaction (HER). However, the family of layered TMDs is mainly limited to Group IV-VII transition metals, while the synthesis of layered TMDs based on metals from other groups still remains a challenge. Herein, we demonstrate by atomic-resolution transmission electron microscopy that hexagonal RuSe2 (h-RuSe2 ) nanosheets with a mixture of 2H and 1T phases can be obtained by a facile bottom-up colloidal synthetic approach. The obtained h-RuSe2 , which can be transformed into the thermodynamically favorable phase of cubic RuSe2 (c-RuSe2 ) only after annealing at 600 °C, exhibits Pt-like HER performance, with a fivefold turnover frequency enhancement compared to the c-RuSe2 in alkaline media. Experimental results and density functional theory (DFT) calculations reveal that the enhanced adsorption free energies of H2 O (ΔG H 2 O * ), optimized adsorption free energies of H (ΔGH* ), and increased conductivity of h-RuSe2 contribute to its superior HER activity.

Polymorphism is a common phenomenon in nature. Here, we report one-pot wet chemical method to synthesize two polymorphs of Au19Ag4(S-Adm)15 nanocluster protected by 1-adamantanethiol (HS-Adm), which adopt P-1 and P21/c space group respectively. The crystal structures of two polymorphs were determined by X-ray crystallography. Compared to the previously reported Au19Ag4(S-Adm)15 nanocluster adopting P21/n space group, polymorphs of Au19Ag4(S-Adm)15 with P-1 and P21/c space group show the different optical properties. Moreover, Au19Ag4(S-Adm)15 with P-1 space group exhibits good thermal stability. Meanwhile, we investigated the effect of solvent and molar ratio of metal precursors on the polymorphs. This work provides an insight to polymorphs of metal nanoclusters.

The construction of C(sp2)-X (X = B, N, O, Si, P, S, Se, etc.) bonds has drawn growing attention since heteroatomic compounds play a prominent role from biological to pharmaceutical sciences. The current study demonstrates the C(sp2)-S/Se and C(sp2)-N bond formation of one carbon of isocyanides with thiophenols or disulfides or diselenides and azazoles simultaneously. The reported findings could provide access to novel multiple isothioureas, especially hitherto rarely reported selenoureas. The protocol showed good atom-economy and step-economy with only hydrogen evolution and theoretical calculations accounted for the stereoselectivity of the products. Importantly, the electrochemical reaction could exclusively occur at the isocyano part regardless of the presence of susceptible radical acceptors, such as a broad range of arenes and alkynyl moieties, even alkenyl moieties.

Ion intercalation assisted exfoliation is the oldest and most popular method for the scalable synthesis of molybdenum disulfide (MoS

An enantioselective nickel-catalyzed intramolecular reductive cross-coupling of C(sp

Chiral nitriles are valuable molecules in modern organic synthesis and drug discovery. Selectively differentiating the two nitrile groups of widely available malononitrile derivatives is a straightforward yet underdeveloped route to construct enantioenriched nitriles. Here we report an enantioselective nickel-catalyzed desymmetrization of malononitriles for the generation of nitrile-containing all-carbon quaternary stereocenters. This protocol involves a nickel-catalyzed addition of aryl boronic acids to alkynes, followed by a selective nitrile insertion, providing unprecedented access to enantioenriched 5-7-membered α-cyano-cycloenones with a fully substituted olefin from a broad range of substrates. The synthetic utility of these nitrile products is demonstrated by gram-scale synthesis and conversion to several useful functional groups.

Doping foreign atom(s) in metal nanoclusters is an effective strategy to engineer the properties and functionalities of metal nanoclusters. However, until now, to dope Pd atom into Ag nanoclusters remains a huge challenge. Here we develop a one-step rapid method to synthesize the Pd-doped Ag nanocluster with high yield. The prepared Pd1Ag28 nanocluster was characterized by mass spectroscopy, X-ray photoelectron spectroscopy, X-ray crystallography, fluorescence spectroscopy, ultraviolet–visible absorption spectroscopy and transient absorption spectroscopy. The nanocluster exhibits a perfect face-centered cubic (FCC) kernel structure with a tetrahedron-like shell. Of note, Pd1Ag28 nanocluster had an unexpectedly long excited-state lifetime of 3.3 microseconds, which is the longest excited-state lifetime for Ag-based nanoclusters so far. Meanwhile, the excellent near-infrared luminescence indicated the nanocluster has the potential in fluorescent bio-imaging. Besides, it was revealed that Pd1Ag28 nanocluster could be transformed into Au1Ag28 nanocluster via ion exchange reaction of AuPPh3Cl with Pd1Ag28 nanocluster. This work provides an efficient synthetic protocol of alloy nanoclusters and will contribute to study the effect of foreign atom on the properties of metal nanoclusters.

A palladium-catalyzed arylation/aza-Michael addition cascade reaction of β-substituted cyclic enones and 2-haloanilines has been reported. Using 1 mol% Pd(PPh3)4 as a catalyst, C2-spiroindolines are accessed via an intermolecular vinylogous arylation of β-alkyl cyclic enones and 2-haloanilines followed by an intramolecular aza-Michael addition. The functional group tolerance of this transformation is examined by 18 examples in up to 93% yield. In the second part, we developed an α′-arylation/aza-Michael addition cascade strategy to construct azabicyclo[3.2.2]nonanones catalyzed by Pd(MeCN)2Cl2·PPh3. This study provides a quick route to complex and useful spiro- and bridged-heterocycles from readily available starting materials in good yields with high regioselectivity.

We report the design and synthesis of a titanium catecholate framework, MOF-217, comprised of 2,4,6-tri(3,4-dihydroxyphenyl)-1,3,5-triazine (TDHT) and isolated TiO6 clusters, with 2-fold interpenetrated srs topology. The dynamics of the organic linker, breaking the C3h symmetry, allowed for reversible twist and sliding between interpenetrated frames upon temperature change and the inclusion of small molecules. Introduction of 28 wt% imidazole into the pores of MOF-217, 28% Im-in-MOF-217, resulted in four orders of magnitude increase in proton conductivity, due to the appropriate accommodation of imidazole molecules and their proton transfer facilitated by the H-bond to the MOF structure across the pores. This MOF-based proton conductor can be operated at 100 °C with a proton conductivity of 1.1 × 10−3 S cm−1, standing among the best performing anhydrous MOF proton conductors at elevated temperature. The interframe dynamics represents a unique feature of MOFs that can be accessed in the future design of proton conductors., Twist and sliding dynamics observed in a titanium catecholate MOF induced by imidazole for efficient proton conduction.

Lithium-rich layered oxides (LLOs) have been extensively studied as cathode materials for lithium-ion batteries (LIBs) by researchers all over the world in the past decades due to their high specific capacities and high charge-discharge voltages. However, as cathode materials LLOs have disadvantages of significant voltage and capacity decays during the charge-discharge cycling. It was shown in the past that fine-tuning of structures and compositions was critical to the performances of this kind of materials. In this report, LLOs with target composition of Li1.17Mn0.50Ni0.24Co0.09O2 were prepared by carbonate co-precipitation method with different pH values. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), and electrochemical impedance spectroscopies (EIS) were used to investigate the structures and morphologies of the materials and to understand the improvements of their electrochemical performances. With the pH values increased from 7.5 to 8.5, the Li/Ni ratios in the compositions decreased from 5.17 to 4.64, and the initial Coulombic efficiency, cycling stability and average discharge voltages were gained impressively. Especially, the material synthesized at pH = 8.5 delivered a reversible discharge capacity of 263 mAhg−1 during the first cycle, with 79.0% initial Coulombic efficiency, at the rate of 0.1 C and a superior capacity retention of 94% after 100 cycles at the rate of 1 C. Furthermore, this material exhibited an initial average discharge voltage of 3.65 V, with a voltage decay of only 0.09 V after 50 charge-discharge cycles. The improved electrochemical performances by varying the pH values in the synthesis process can be explained by the mitigation of layered-to-spinel phase transformation and the reduction of solid-electrolyte interface (SEI) resistance. We hope this work can shed some light on the alleviation of voltage and capacity decay issues of the LLOs cathode materials.

We report the design and synthesis of a bismuth metal–organic framework (MOF), MOF-836. This MOF is loaded with Sb salts in its pores and is used as the precursor for the production of Bi–Sb alloy ...

An efficient desymmetrization of γ-quaternary carbon-containing cyclohexanones using readily available Pd/(S)-tBuPhox and benzylamine as dual catalysts is reported. We describe herein the developme...

The construction of C(sp2)–X (X = B, N, O, Si, P, S, Se, etc.) bonds has drawn growing attention since heteroatomic compounds play a prominent role from biological to pharmaceutical sciences. The current study demonstrates the C(sp2)–S/Se and C(sp2)–N bond formation of one carbon of isocyanides with thiophenols or disulfides or diselenides and azazoles simultaneously. The reported findings could provide access to novel multiple isothioureas, especially hitherto rarely reported selenoureas. The protocol showed good atom-economy and step-economy with only hydrogen evolution and theoretical calculations accounted for the stereoselectivity of the products. Importantly, the electrochemical reaction could exclusively occur at the isocyano part regardless of the presence of susceptible radical acceptors, such as a broad range of arenes and alkynyl moieties, even alkenyl moieties., We have developed an efficient and sustainable electrochemical strategy for the double C(sp2)–X (S/Se, N) bond formation of isocyanides simultaneously. A series of novel isothio/selenoureas were obtained via a three-component cross-coupling.

Herein we report an asymmetric two-component vinylogous Catellani reaction for the construction of C-N axial chirality through a palladium/chiral norbornene cooperative catalysis and an axial-to-axial chirality transfer process. Various partially aromatic iodinated 2-pyridones, quinolones, coumarin and uracil substrates react with 2,6-disubstituted aryl bromides with a tethered amide group, to afford a wide variety of polycyclic C-N atropisomers (39 examples, up to 97% ee ). The obtained C-N axial chirality is originated from the preformed transient C-C axial chirality with high fidelity. The synthetic utility of this chemistry is demonstrated by facile preparation of complex quinoline and pyridine based C-N atropisomers through a N -deprotection and aromatization sequence. In addition, a remote axial-to-central diastereoinduction process dictated by C-N axial chirality is observed with excellent diastereocontrol. This research opens a new avenue for asymmetric synthesis.

Herein, we report a modular and convergent strategy for the assembly of atropisomeric

As significant pharmacophores, 1,3-disubstituted cyclohexanes are widespread in natural products and synthetic bioactive molecules. In this work, we describe a palladium-catalyzed arylboration of 1,4-cyclohexadienes, which allows expeditious access to an array of functionalized 1,3-disubstituted cyclohexanes from the readily available starting materials. Palladium catalysis enables the arylboration to proceed in a reversed regioselectivity compared with earlier nickel catalysis. The most striking feature of this protocol lies in the 1,3-regioselectivity and exclusive cis-diastereoselectivity. Intriguingly, the success of this three-component reaction does not rely on the application of dative ligands but a cheap ammonium chloride salt instead. The synthetic utility of this method is highlighted by a series of downstream stereospecific transformations and a drug molecule synthesis.

We present a simple in situ sodium borohydride (NaBH4) reduction approach to produce amorphous core–shell like cobalt borate nanosheet-coated cobalt boride hybrid (Co-B@Co-Bi). Benefiting from the unique rich amorphous Co-Bi layer, it exhibits extraordinary catalytic activity and good stability toward the oxygen evolution reaction (OER) in 1.0 M KOH, with an overpotential of 291 mV to obtain a current density of 10 mA cm–2, outperforming most of the documented metal–metalloid-based electrocatalysts. This reverse addition strategy might provide a promising pathway for designing various transition metal borate and boride hybrid for more applications.

Oxidative C–H/N–H cross-coupling is one of the most atom-economical methods for the construction of C–N bonds. However, traditional oxidative C–H/N–H cross-coupling either required the use of strong oxidants or high reaction temperature, which makes it difficult to tolerate redox active functional groups. Herein we describe an external chemical oxidant-free electrooxidative C–H/N–H cross-coupling between electron-rich arenes and diarylamine derivatives. Under undivided electrolytic conditions, a series of triarylamine derivatives are produced from electron-rich arenes and diarylamine derivatives with high functional group tolerance. Both of the coupling partners are redox active in oxidative C–H/N–H cross-coupling, which enables high regioselectivity in C–N bond formation. Exclusive para-selectivity is observed for the coupling with anilines., Oxidative C–H/N–H cross-coupling is a convenient method to construct C–N bonds, however this is rarely achieved in a sustainable manner. Here, the authors show an oxidant-free electrochemical C–H/N–H cross-coupling between electron-rich arenes and diarylamines to afford triarylamines with exclusive para-selectivity.

Site-selective intermolecular C–H bond functionalization is of central importance to synthetic chemistry. In particular, direct β-functionalization of N-heterocycles still remains a great challenge. Herein, we develop a strategy for oxidation-induced thiolation and selenation at the β-position of piperidine derivatives and 1,2,3,4-tetrahydroisoquinoline via C–H bond functionalization. Various 4-sulfenylisoquinolines, 3-sulfenylpyridines, and 4-selenylisoquinolines can be obtained by using O2 as the only oxidant. Notably, neither a directing group nor a metal catalyst is necessary in this transformation. The preliminary mechanistic studies revealed that the oxidation and rearrangement pathway were key steps in this transformation, which provides a meaningful strategy for controlling site selectivity in the β-functionalization of N-heterocycles.

It is desirable to develop pure organic molecules with persistent room temperature luminescence for time-resolved imaging on low-cost instruments. However, the persistent luminescence of many organic molecules is usually observed only in the crystalline state, limiting their broad range of applications in composites with low doping concentrations. Herein, we demonstrate a facile strategy to generate an emitter with long-lived luminescence in both crystalline and amorphous states. By utilizing intramolecular electronic coupling, CzDPS [9-9′-(sulfonylbis(2,1-phenylene))bis(9H-carbazole)] was designed and synthesized, which could emit persistent luminescence in crosslinked polymers with a doping concentration of only 1 wt%. Moreover, the ultra-long persistent luminescence of its powder crystals enables its use in time-resolved luminescence imaging of fingerprints by only using a smartphone under a UV LED. Notably, the interference from fluorescent substrates could be eliminated by photographing after turning off the light. This finding provides a new and facile strategy for forensic investigation of fingerprints which suffers from interference from the scattering and fluorescence signals of substrates.