General Strategy For Synthesis Research Articles

Novel transition-metal phosphides@N, P-codoped carbon electrocatalysts synthesized via a universal strategy for overall water splitting

Developing highly efficient and stable bifunctional electrocatalysts plays a crucial role in water splitting reaction. Benefiting from their abundant reserves, superior conductivity and excellent intrinsic catalytic properties, transition metal phosphides (TMPs) draw wide attentions in recent years. However, most of TMPs synthesis processes are still acomplicated and dangerous as the common use of toxic and flammable phosphorus sources. Herein, we propose a universal and scalable synthetic strategy to prepare a series of nanosized transition metal phosphide encapsulated in nitrogen-phosphorus co-doped carbon (TMP@NPC) catalysts by using green and inexpensive adenosine triphosphate (ATP) as a new phosphorus source. Profiting from the in situ and confined synthetic strategy, as-prepared TMP@NPC catalysts not only show nanosized dimension, but also endow extremely intimate interaction with N, P component derived from ATP. All as-prepared TMP@NPC catalysts exhibit excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities with small overpotentials and robust capabilities. Especially, the CoP@NPC displays the lowest overpotentials of 184.35 mV and 303 mV at 10 mA cm−2 toward HER and OER in alkaline electrolyte, respectively, which also exhibits outstanding stability (over 50 h at 10 mA cm−2) in both reactions. As a proof of further application, as-prepared CoP@NPC acting as both cathode and anode shows excellent performance in overall water splitting. This work not only highlights the green and general synthesis strategy importance in designing and constructing TMPs, but also reinforces the understanding of intimate interaction in coupled hybrid electrocatalysts.

Tuning Electronic Structure and Composition of FeNi Nanoalloys for Enhanced Oxygen Evolution Electrocatalysis via a General Synthesis Strategy

Developing low-cost and efficient oxygen evolution electrocatalysts is key to decarbonization. A facile, surfactant-free, and gram-level biomass-assisted fast heating and cooling synthesis method is reported for synthesizing a series of carbon-encapsulated dense and uniform FeNi nanoalloys with a single-phase face-centered-cubic solid-solution crystalline structure and an average particle size of sub-5nm. This method also enables precise control of both size and composition. Electrochemical measurements show that among Fex Ni(1- x ) nanoalloys, Fe0.5 Ni0.5 has the best performance. Density functional theory calculations support the experimental findings and reveal that the optimally positioned d-band center of O-covered Fe0.5 Ni0.5 renders a half-filled antibonding state, resulting in moderate binding energies of key reaction intermediates. By increasing the total metal content from 25 to 60 wt%, the 60% Fe0.5 Ni0.5 /40% C shows an extraordinarily low overpotential of 219mV at 10 mA cm-2 with a small Tafel slope of 23.2 mV dec-1 for the oxygen evolution reaction, which are much lower than most other FeNi-based electrocatalysts and even the state-of-the-art RuO2 . It also shows robust durability in an alkaline environment for at least 50h. The gram-level fast heating and cooling synthesis method is extendable to a wide range of binary, ternary, quaternary nanoalloys, as well as quinary and denary high-entropy-alloy nanoparticles.

General Synthesis and Solution Processing of Metal-Organic Framework Nanofibers.

By virtue of their extraordinarily high surface areas, ordered pore structures, various compositions, and rich functionality, metal-organic frameworks (MOFs) are of great interest in diverse fields such as gas separation, sensing, catalysis, energy, environment science, and biomedicine. However, the difficulty in processing MOF crystals and controlling the MOF superstructure is emerging as a critical issue in their application. Herein, it is reported that a robust template, i.e., nanofibrillated cellulose (NFC), can be used for the synthesis of MOF materials with 1D nanofiber morphology. NFC@MOF core-shell nanofibers with a uniform network structure and high aspect ratios can be prepared by use of this template. The small crystal size, flexibility, and good dispersity of the NFC@MOF nanofibers make it convenient for the macroscale assembly and solution processing of MOF materials. A proof-of-concept study is demonstrated wherein freestanding MOF nanofiber membranes represent good performance in applications of water treatment and heterogeneous catalysis reaction. This general synthesis and solution-processing strategy may herald a new era in promoting the industrial application of MOFs.

Modular access to substituted cyclohexanes with kinetic stereocontrol.

Substituted six-membered cyclic hydrocarbons are common constituents of biologically active compounds. Although methods for the synthesis of thermodynamically favored, disubstituted cyclohexanes are well established, a reliable and modular protocol for the synthesis of their stereoisomers is still elusive. Herein, we report a general strategy for the modular synthesis of disubstituted cyclohexanes with excellent kinetic stereocontrol from readily accessible substituted methylenecyclohexanes by the implementation of chain-walking catalysis. Mechanistically, the initial introduction of a sterically demanding boron ester group adjacent to the cyclohexane is key to guiding the stereochemical outcome. The synthetic potential of this methodology has been highlighted in late-stage modification of complex bioactive molecules and in comparison with current cross-coupling techniques.

An all-C–H-activation strategy to rapidly synthesize high-mobility well-balanced ambipolar semiconducting polymers

<h2>Summary</h2> Ambipolar semiconducting polymers are of significant fundamental and technical interest. However, the tedious syntheses of using classic C(sp²)–C(sp²) coupling reactions make high-performance ambipolar polymers seriously absent. In order to address this dilemma, we report here an all-C–H-activation strategy to efficiently synthesize high-performance ambipolar polymers. Diketopyrrolopyrrole-dimer-type monomers and their acceptor-acceptor-type polymers are used as examples. Remarkably, two-step C–H activation reactions from monomer syntheses to polymerization can be accomplished within 2 h, affording a series of semiconducting polymers applied in flexible organic transistors with high and ideally balanced hole and electron mobilities up to 3.56 and 3.75 cm² V⁻¹ s⁻¹, respectively. Furthermore, controlled molecular weight can be realized by varying the polymerization time, which is very important for regulating the trade-off between high mobility and suitable solution processability. Overall, this work offers a general strategy for the rapid synthesis of semiconducting polymers, potentially leading to wide applications of organic electronics.

Cofactor-Driven Cascade Reactions Enable the Efficient Preparation of Sugar Nucleotides.

Glycosylation is catalyzed by glycosyltransferases using sugar nucleotides or occasionally lipid-linked phosphosugars as donors. However, only very few common sugar nucleotides that occur in humans can be obtained readily, while the majority of sugar nucleotides that exist in bacteria, plants, archaea, or viruses cannot be synthesized in sufficient quantities by either enzymatic or chemical synthesis. The limited availability of such rare sugar nucleotides is one of the major obstacles that has greatly hampered progress in glycoscience. Herein we describe a general cofactor-driven cascade conversion strategy for the efficient synthesis of sugar nucleotides. The described strategy allows the large-scale preparation of rare sugar nucleotides from common sugars in high yields and without the need for tedious purification processes.

A General Concurrent Template Strategy for Ordered Mesoporous Intermetallic Nanoparticles with Controllable Catalytic Performance

AbstractWe report a general concurrent template strategy for precise synthesis of mesoporous Pt‐/Pd‐based intermetallic nanoparticles with desired morphology and ordered mesostructure. The concurrent template not only supplies a mesoporous metal seed for re‐crystallization growth of atomically ordered intermetallic phases with unique atomic stoichiometry but also provides a nanoconfinement environment for nanocasting synthesis of mesoporous nanoparticles with ordered mesostructure and rhombic dodecahedral morphology under elevated temperature. Using the selective hydrogenation of 3‐nitrophenylacetylene as a proof‐of‐concept catalytic reaction, mesoporous intermetallic PtSn nanoparticles exhibited remarkably controllable intermetallic phase‐dependent catalytic selectivity and excellent catalytic stability. This work provides a very powerful strategy for precise preparation of ordered mesoporous intermetallic nanocrystals for application in selective catalysis and fuel cell electrocatalysis.

Ion implantation synthesis of long-term stable high-entropy metallic glass nanoparticles

High-entropy metallic glass nanoparticles (HEMG-NPs) have shown great potential in the development of sustainable energy. Discovering new nanomaterials for electrocatalysis and maintaining their long-term stability is an effective way. The presence of nanoparticles in an independent transparent substrate material provides a unique way for its stability and maximum performance. This special composite structure is very beneficial to the study of the fine structure of a single specific particle. Here, we propose a general synthesis strategy, in which alloy targets are implanted into the substrate by ion implantation and annealed to grow into NPs. The disordered arrangement of ions into the substrate and the subsequent slow dynamics, disordered microscopic microstructure. Calculating the similarity of the depth range of simulated metal ion implantation provides a theoretical basis for the successful formation of HEMG-NPs. Electrocatalytic water splitting shows that CuCoNiFeZn HEMG-NPs is a non-precious single nano-microcatalyst suitable for multifunctional (HER and OER) electrocatalysis, highlighting its application in sustainable energy conversion. The use of ion implantation aims to synthesize HEMG-NPs with long-term stable storage and minimized denaturation. In further research, the formation of fine structure corresponds to the law of electrocatalytic activity. Develop high-efficiency electrocatalytic HEMG-NPs materials based on the original microstructure.

C-C Bond Cleavage of α-Pinene Derivatives Prepared from Carvone as a General Strategy for Complex Molecule Synthesis.

The preparation of complex molecules (e.g., biologically active secondary metabolites) remains an important pursuit in chemical synthesis. By virtue of their sophisticated architectures, complex natural products inspire total synthesis campaigns that can lead to completely new ways of building molecules. In the twentieth century, one such paradigm which emerged was the use of naturally occurring "chiral pool terpenes" as starting materials for total synthesis. These inexpensive and naturally abundant molecules provide an easily accessed source of enantioenriched material for the enantiospecific preparation of natural products. The most common applications of chiral pool terpenes are in syntheses where their structure can, entirely or largely, be superimposed directly onto a portion of the target structure. Less straightforward uses, where the structure of the starting chiral pool terpene is not immediately evident in the structure of the target, can be more challenging to implement. Nevertheless, these "nonintuitive" approaches illustrate the ultimate promise of chiral pool-based strategies: that any single chiral pool terpene could be applied to syntheses of an indefinite number of structurally diverse complex synthetic targets.By definition, such strategies require carefully orchestrated sequences of C-C bond forming and C-C cleaving reactions which result in remodeling of the terpene architecture. The combination of traditional rearrangement chemistry and transition-metal-catalyzed C-C cleavage methods, the latter of which were primarily developed in the early twenty-first century, provide a rich and powerful toolbox for implementing this remodeling approach. In this Account, we detail our efforts to use a variety of C-C cleavage tactics in the skeletal remodeling of carvone, a chiral pool terpene. This skeletal remodeling strategy enabled the reorganization of the carvone scaffold into synthetic intermediates with a variety of carboskeletons, which we, then, leveraged for the total syntheses of structurally disparate terpene natural products.We begin by describing our initial investigations into various, mechanistically distinct C-C cleavage processes involving cyclobutanols synthesized from carvone. These initial studies showcased how electrophile-mediated semipinacol rearrangements of these cyclobutanols can lead to [2.2.1]bicyclic intermediates, and how Rh- and Pd-catalyzed C-C cleavage can lead to a variety of densely functionalized cyclohexenes pertinent to natural product synthesis. We, then, present several total syntheses using these synthetic intermediates, beginning with the bridged, polycyclic sesquiterpenoid longiborneol, which was synthesized from a carvone-derived [2.2.1]bicycle following a key semipinacol rearrangement. Next, we discuss how several members of the macrocyclic phomactin family were synthesized from a cyclohexene derivative prepared through a Rh-catalyzed C-C cleavage reaction. Finally, we describe our synthesis of the marine diterpene xishacorene B, which was prepared using a key Pd-catalyzed C-C cleavage/cross-coupling that facilitated the assembly of the core [3.3.1]bicycle that is resident in the natural product structure.

Synthesis of Polyoxygenated Tropolones and their Antiviral Activity against Hepatitis B Virus and Herpes Simplex Virus-1.

Polyoxygenated tropolones possess a broad range of biological activity, and as a result are promising lead structures or fragments for drug development. However, structure-function studies and subsequent optimization have been challenging, in part due to the limited number of readily available tropolones and the obstacles to their synthesis. Oxidopyrylium [5+2] cycloaddition can effectively generate a diverse array of seven-membered ring carbocycles, and as a result can provide a highly general strategy for tropolone synthesis. Here, we describe the use of 3-hydroxy-4-pyrone-based oxidopyrylium cycloaddition chemistry in the synthesis of functionalized 3,7-dimethoxytropolones, 3,7-dihydroxytropolones, and isomeric 3-hydroxy-7-methoxytropolones through complementary benzyl alcohol-incorporating procedures. The antiviral activity of these molecules against herpes simplex virus-1 and hepatitis B virus is also described, highlighting the value of this approach and providing new structure-function insights relevant to their antiviral activity.

DNA-Compatible Diversification of Indole π-Activated Alcohols via a Direct Dehydrative Coupling Strategy.

Indole-based diversification is highly desired in the DNA-encoded chemical library construction. Herein, we present a general strategy for on-DNA synthesis of diverse C3-functionalized indole derivatives via indole π-activated alcohol formation followed by direct dehydrative coupling. Highly efficient bond linkages of C-C, C-N, and C-S were achieved to fuse building blocks that are widely commercially available. DNA-encoding compatibility of the method has been further demonstrated to pave an avenue for application in constructing indole-focused three-dimensional libraries.

Recent topics on circularly polarized luminescence generated by inorganic materials

Circularly polarized luminescence (CPL) is an interesting phenomenon representing the unequal emission of left-handed and right-handed polarized light from an emitter. CPL is promising in chirality characterizations and various optical applications. Traditionally, research on CPL is centered on organic substances. In recent years, CPL present on inorganic ones has also become a nascent topic, which is significant to explore novel chirality- and luminescence-related properties and applications in inorganic materials. This minireview summarizes the recent progress on the following two aspects: 1) how to endow common inorganic luminophores with CPL activity; 2) how to use emerging chiral inorganic nanomaterials to design CPL-active systems. The general synthesis strategies, optical properties, applications and outlook of CPL-active inorganic materials are demonstrated.

General synthesis strategy of ZrO2 nanofilms with few-atom layered thickness for boosting triethylamine detection.

ZrO2, a traditional inert transition metal oxide (TMO), can be prepared into ZrO2 nanofilms (NFs) with a single-layer thickness of only 2.5 nm through the generally applicable two-dimensional TMO synthesis strategy reported by us, and has displayed remarkable sensitivity and selectivity properties for triethylamine gas detection.

A General Strategy for Instantaneous and Continuous Synthesis of Ultrasmall Metal–Organic Framework Nanoparticles

AbstractUltrasmall metal–organic frameworks (MOFs) may generate unique properties to expand the scope of applications. However, the synthesis is still a great challenge. Herein, we propose a strategy to synthesize ultrasmall MOFs by high gravity technology. With the aid of tremendous intensification of molecular mixing and mass transfer in high‐gravity field, six typical MOFs were obtained instantaneously in a continuous way. These samples are monodispersed with sub‐5 nm in size, smaller than the previously reported values and even close to the length of one crystal unit cell. As a proof‐of‐concept, catalytic activity for Knoevenagel reaction can be significantly enhanced using ultrasmall ZIF‐8. Conversion time of benzaldehyde was decreased by 94 % or 75 % compared to those using conventional or hierarchically porous ZIF‐8. More importantly, this approach is readily scalable with the highest space‐time yield for nano‐MOFs, which may promote the convenient synthesis and practical applications of ultrasmall MOFs in large‐scale.

A General Strategy for Instantaneous and Continuous Synthesis of Ultrasmall Metal-Organic Framework Nanoparticles.

Ultrasmall metal-organic frameworks (MOFs) may generate unique properties to expand the scope of applications. However, the synthesis is still a great challenge. Herein, we propose a strategy to synthesize ultrasmall MOFs by high gravity technology. With the aid of tremendous intensification of molecular mixing and mass transfer in high-gravity field, six typical MOFs were obtained instantaneously in a continuous way. These samples are monodispersed with sub-5 nm in size, smaller than the previously reported values and even close to the length of one crystal unit cell. As a proof-of-concept, catalytic activity for Knoevenagel reaction can be significantly enhanced using ultrasmall ZIF-8. Conversion time of benzaldehyde was decreased by 94 % or 75 % compared to those using conventional or hierarchically porous ZIF-8. More importantly, this approach is readily scalable with the highest space-time yield for nano-MOFs, which may promote the convenient synthesis and practical applications of ultrasmall MOFs in large-scale.

Brookite TiO2 Nanoparticles Decorated with Ag/MnOx Dual Cocatalysts for Remarkably Boosted Photocatalytic Performance of the CO2 Reduction Reaction.

The solar-driven CO2 reduction reaction (CO2RR) for producing chemical fuels is considered to be a promising approach to dealing with the growing energy crisis and greenhouse effect. Herein, novel Ag/MnOx dual-cocatalyst-decorated brookite titania (BT) nanoparticles with remarkably boosted photocatalytic CO2RR performance are prepared through a facile photodeposition method. The resultant xAg-BT-yMn composite with optimal cocatalyst content delivers amazing CO/CH4 yields of 31.70/129.98 μmol g-1 with an overall photoactivity of 1103.28 μmol g-1 h-1, 11.98 times higher than that of the BT nanoparticles alone. Further investigations demonstrate that the dual cocatalysts decorating the BT nanoparticles not only effectively retard the photoinduced charge recombination but also significantly vary the surface chemical feature to promote the adsorption/activation of the reactants (CO2/H2O). In addition, the Ag nanoparticles can broaden the spectral response region, while the MnOx cocatalyst can promote the CH4 product selectivity and the water oxidation reaction. The synergistic effect of Ag/MnOx dual cocatalysts on the BT nanoparticles renders a remarkably boosted CO2RR performance, which provides a simple yet general synthesis strategy for brookite titania-based photocatalysts with high-performance solar-driven CO2 conversion.

Photocatalyst with Chloroplast‐like Structure for Enhancing Hydrogen Evolution Reaction

Photosynthesis with the chloroplast works efficiently because of the envelope structure that serves to carry enzymes and to simultaneously maintain the spatial separation of photosynthesis and cellular respiration. Inspired by the spatially separated architecture, a chloroplast‐like structured photocatalyst (PdS@CdS@MoS2), in which the PdS and MoS2 function as enzymes in the chloroplast and CdS shell functions as the chloroplast envelope, was developed to improve the photocatalytic H2 evolution. In this unique nanoscale bionic structure, the poriferous CdS shell enhances light absorption, generates photoinduced carriers, and separates oxidation and reduction reactions. Meanwhile, PdS and MoS2 dual cocatalysts enhance the charge separation efficiency through forming a built‐in electric field with CdS. We demonstrate that the separation efficiency of carriers, carrier lifetime, and the yield of H2 are both higher than that of CdS nanoparticles, evidencing the feasibility of the chloroplast‐like structure in enhancing the photocatalyst activity. This work emphasizes the synergism of the three key processes of the photocatalytic reaction by simulating the chloroplast structure and provides a general synthesis strategy, the synthesis of novel structured for photocatalysts for diverse applications in the energy field.

Ziyang Zhang

Ziyang Zhang says he is a chemist at heart, but you would be hard pressed to find another scientist his age whose work stands poised to impact so many fields of medicine. At 30, he has already synthesized new potential antibiotics, targeted one of the most notoriously hard-to-drug proteins in cancer, investigated potential antivirals for COVID-19, and designed a new strategy for directing the immune system to attack tumors. And he won’t even start his own lab until next year. As a first-year PhD student at Harvard University, Zhang jumped on a project in Andrew G. Myers’s lab to devise a general strategy for the total synthesis of macrolides, a class of well-known and widely used antibiotics with complex structures. Chemists have traditionally made these antibiotics by modifying naturally derived macrolides—an approach that limits the potential diversity of new molecules. “They are not trivial to make from scratch,” Zhang says.

A General Synthesis Strategy for Hollow Metal Oxide Microspheres Enabled by Gel‐Assisted Precipitation

AbstractHollow metal oxide microspheres (HMMs) have drawn enormous attention in different research fields. Reliable and scalable synthetic protocols applicable for a large variety of metal oxides are in emergent demand. Here we demonstrated that polymer hydrogel, such as the resorcinol formaldehyde (RF) one, existed as an efficient synthetic platform to build HMMs. Specifically, the RF gel forms stacked RF microspheres enlaced with its aqueous phase, where the following evaporation of the highly dispersed water leads to a gel‐assisted precipitation (GAP) of the dissolved metal precursor onto the embedded polymeric solids suited for the creation of HMMs. By taking advantage of the structural features of hydrogel, this synthesis design avoids the delicate control on the usually necessitated coating process and provides a simple and effective synthetic process versatile for functional HMMs, particularly Nb2O5 as a high‐performance electrode material in Li‐ion intercalation pseudocapacitor.

A General Synthesis Strategy for Hollow Metal Oxide Microspheres Enabled by Gel-Assisted Precipitation.

Hollow metal oxide microspheres (HMMs) have drawn enormous attention in different research fields. Reliable and scalable synthetic protocols applicable for a large variety of metal oxides are in emergent demand. Here we demonstrated that polymer hydrogel, such as the resorcinol formaldehyde (RF) one, existed as an efficient synthetic platform to build HMMs. Specifically, the RF gel forms stacked RF microspheres enlaced with its aqueous phase, where the following evaporation of the highly dispersed water leads to a gel-assisted precipitation (GAP) of the dissolved metal precursor onto the embedded polymeric solids suited for the creation of HMMs. By taking advantage of the structural features of hydrogel, this synthesis design avoids the delicate control on the usually necessitated coating process and provides a simple and effective synthetic process versatile for functional HMMs, particularly Nb2 O5 as a high-performance electrode material in Li-ion intercalation pseudocapacitor.