Aerobic Reconstruction of Amines to Amides: A C-N/C-C Bond Cleavage Approach.

Herein, an aerobic reconstruction of amines to amides via C(sp)-N bond and C(sp)-C(sp) bond cleavage is described. This method features a metal-free reaction, insensitivity to oxygen or moisture, and ambient air as the terminal oxidant. Preliminary mechanistic studies suggest that the reaction pathway of amine oxidation, followed by imine exchange and Beckmann rearrangement, is involved.

Developing bio-carbon matrices for the encapsulation of silicon nanoparticles for high-performance lithium-ion battery anode materials.

Silicon (Si) is considered to be one of the most promising anode materials for next-generation lithium-ion batteries because of its abundant reserves, low discharge potential, and most importantly, its high theoretical specific capacity. However, the practical application of Si-based anodes is mainly hindered by the low intrinsic conductivity of Si and the large volume change upon lithiation/de-lithiation. In order to improve the electrochemical performance of Si-based anodes, we prepared a composite material consisting of Si nanoparticles (NPs) and coconut silk bio-carbon (CSC) skeleton.

Copper-Catalyzed Asymmetric Nucleophilic Substitutions of TsSCF: Synthesis of Chiral SCF-Containing Compounds.

By employing electrophilic TsSCF as an efficient SCF source, we reported Cu/ (chiral sulfoxide-phosphine ligand)-catalyzed enantioselective nucleophilic substitutions. Under this protocol, α-pyridyl-α-fluoro esters as latent carbon nucleophiles, compounds containing a C-SCF stereocenter along with azacycles and fluorine atoms, were obtained in good yields and enantioselectivities under mild conditions (up to 68% yield, 92% ee).

A W/Al Co-doped NaMnO Cathode Material for Enhanced Sodium-Ion Storage.

The NaMnO cathode has attracted enormous interest owing to its low cost, low toxicity, and stable structure, but its practical application is still hindered by the limited sodium storage sites. Element doping is widely used to improve its capacity. However, cation and anion substitution could barely reach a satisfactory compromise between the structural stability and reversible capacity.

Sulfur-Rich Norbornadiene-Derived Infrared Transparent Polymers by Inverse Vulcanization.

Infrared (IR) transparent polymer materials prepared by inverse vulcanization, as a promising candidate to replace inorganic materials, are new materials for constructing key devices in IR optics. However, it is difficult to achieve a balance between infrared optical and thermal properties in polymers due to the intrinsic infrared absorption of organic materials. Herein, our strategy is to construct a high boiling point symmetrical molecular norbornadiene derivative cross-linking agent (DMMD) which can be inverse vulcanized with molten sulfur, and obtain Poly (S-r-DMMD) with different sulfur content by controlling the feed ratio of sulfur.

High sensing performance flexible nanocomposite sensor with a hybrid nanostructure constructed nanoscale confined motion of nanofibers and nanoplatelets.

The swing process between the construction and destruction of hybrid nanostructures in conductive nanocomposites under an external stimulation plays a pivotal role in their sensing performance and is directly related to the nanoscale motion of the corresponding hybrid nanoparticles. When one-dimensional (1D) nanofibers and two-dimensional (2D) nanoplatelets were selectively distributed in thin cell walls supercritical CO foaming, the confined nanoscale motion of 1D nanofibers and 2D nanoplatelets in the stretching process, including hybrid nanoparticle rotation and separation, was precisely regulated based on the hybrid nanoparticles' Monte Carlo theoretical modelling. Correspondingly, an optimized complex hybrid nanostructure with a suitable nanoparticle content, hybrid ratio and geometry was proposed to achieve a high gauge factor of 4469.

Engineering of exosome-liposome hybrid-based theranostic nanomedicines for NIR-II fluorescence imaging-guided and targeted NIR-II photothermal therapy of subcutaneous glioblastoma.

Exosome-liposome hybrid-based vehicles (ELV) are promising carriers for cancer treatment, but there are rare efficient theranostic probes to label their lipid bilayer membrane for precisely tracing biodistribution and execute potent therapy. As both fluorescence imaging and photothermal therapy in the second near-infrared window (NIR-II) has intrinsically deep penetration and high efficacy to ablate tumors, herein the design and synthesis of lipophilic NIR-II cyanine dyes with strong donor strength is reported to label lipid bilayer membrane of ELV for NIR-II fluorescence image-guided and targeted NIR-II photothermal treatment of subcutaneous glioblastoma. Via lipid film hydration and subsequent extrusion method, the synthesized ELV (NIR-C-EL) is formulated with NIR-C labeling, cyclic arginylglycylaspartic acid decoration, liposomal PEGylation, and biological exosome function.

Polypropylene Blends with Durable Hydrophobicity and Enhanced Mechanical Properties Based on POSS and Alkane Modified Polypentafluorophenyl Methacrylate.

Durable functionalization on polypropylene (PP) surfaces is always a key problem to besolved. Coatings with low surface energy peel off easily especially under extreme conditions, owing to their weak adhesion. In this paper, side groups of both polyhedral oligomeric silsesquioxane (POSS) and alkane are grafted to polypentafluorophenyl methacrylate (PFP), and then PP blends with these side-group modified PFP are obtained through a melt-blending process.

A quinine-squaramide catalyzed enantioselective vinylogous Mannich reaction between benzothiazolimines and γ-butenolides for efficient preparation of chiral -benzothiazole butyrolactones.

A highly effective and enantioselective vinylogous Mannich reaction between benzothiazolimines and γ-butenolides catalyzed by a quinine based squaramide has been disclosed. A series of chiral benzothiazole amines containing a γ,γ-disubstituted butanolide scaffold bearing an adjacent chiral stereocenter have been successfully obtained in good to excellent yields (up to 91%) with excellent enantioselectivities (up to >99% ee) and diastereoselectivities (>20 : 1 dr) with broad substrate generality under mild conditions. The new scaffold integrated with both chiral benzothiazolimine and γ-butenolide moieties may provide a possibility for the development of new pharmaceutical entities.

Application of Mesoporous Carbon-Based Highly Dispersed K-O Strong Lewis Base in the Efficient Catalysis of Methanol and Ethylene Carbonate.

As an atom-economical reaction, the direct generation of dimethyl carbonate (DMC) and ethylene glycol (EG) via the transesterification of CHOH and ethylene carbonate (EC) has several promising applications, but the exploration of carriers with high specific surface areas and novel heterogeneous catalysts with more basic sites remains a long-standing research challenge. For this purpose, herein, a nitrogen-doped mesoporous carbon (NMC, 439 m/g) based K-O Lewis base catalyst (K-O/NMC) with well-dispersed strongly basic sites (2.23 mmol/g, 84.

Photomediated One-Pot Three-Component Approach Enables the Formal Direct -Acylation/Sulfonylation and α-C-H Functionalization of 1,2,3,4-Tetrahydroisoquinoline.

-Acyl/sulfonyl-α-functionalized 1,2,3,4-tetrahydroisoquinolines (THIQs) are significant structural motifs in organic synthesis and drug discovery. However, the one-pot approach enabling direct difunctionalization of THIQs remains challenging. Herein we report a photomediated one-pot three-component strategy to access -acyl/sulfonyl-α-functionalized THIQs.

Surface Reaction for the Preparation of High-Performance Li-Rich Mn-Based Cathode Materials with Integrated Surface Functionalization.

Li-rich Mn-based cathode materials (LLOs) are often faced with problems such as low initial Coulombic efficiency (ICE), limited rate performance, voltage decay, and structural instability. Addressing these problems with a single approach is challenging. To overcome these limitations, we developed an LLO with surface functionalization using a simple fabrication method.

Practical synthesis of chenodeoxycholic acid from phocaecholic acid.

In this study, we developed an effective method for the large-scale synthesis of chenodeoxycholic acid (CDCA) from phocaecholic acid (PhCA). A high total yield of up to 72 % was obtained via five steps including methyl esterification, Ts-protection, bromination, reduction, and hydrolysis. The structures of the intermediates were confirmed by H NMR (Nuclear Magnetic Resonance), C NMR, HRMS (High Resolution Mass Spectrometry), and IR (Infrared Spectroscopy) spectroscopies.

Regioselective and enantioselective propargylic hydroxylations catalyzed by P450tol monooxygenases.

Regioselective and enantioselective hydroxylation of propargylic C-H bonds are useful reactions but often lack appropriate catalysts. Here a green and efficient asymmetric hydroxylation of primary and secondary C-H bonds at propargylic positions has been established. A series of optically active propargylic alcohols were prepared with high regio- and enantioselectivity (up to 99% ee) under mild reaction conditions by using P450tol, while the C≡C bonds in the molecule remained unreacted.

Palladium-Catalyzed Cycloaddition Reactions of π-Allylpalladium 1,4-Dipoles with 1,3,5-Triazinanes: Access to Hexahydropyrimidines, 1,3-Oxazinanes, and 1,5-Diazocanes.

Palladium-catalyzed decarboxylation of 5-methylene-1,3-oxazinan-2-ones and 5-methylene-1,3-dioxan-2-ones to generate aza-π-allylpalladium and oxa-π-allylpalladium 1,4-dipoles for [4 + 2] cycloaddition reaction with 1,3,5-triazinanes was developed, affording a wide range of hexahydropyrimidine and 1,3-oxazinane derivatives in good to excellent yields (up to 99%). The acyclic sulfonamido-substituted allylic carbonates as aza-π-allylpalladium 1,4-dipole precursors also apply to the developed synthesized strategy, achieving the synthesis of hexahydropyrimidines. Moreover, the in situ-generated aza-π-allylpalladium 1,4-dipoles undergoing dimeric [4 + 4] cycloaddition were also demonstrated by the construction of 1,5-diazocane derivatives.

New eremophilane-type sesquiterpenes from Synotis solidaginea.

Eleven new highly oxygenated eremophilane-type sesquiterpenoids were isolated from the whole plant of Synotis solidaginea, including two pairs of C-8 S/R epimers. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analysis and the absolute configurations of 1 and 9 were confirmed by single-crystal X-ray crystallography using Cu Kα radiation. All the isolates were tested for the inhibition of LPS-stimulated NO production in macrophage-like mouse monocytic leukemia RAW264.

Palladium-Catalyzed Asymmetric Decarboxylation of 5-Vinyloxazolidine-2,4-Diones Triggering the Dearomatization of Electron-Deficient Indoles for the Synthesis of Chiral Highly Functionalized Pyrroloindolines.

A catalyst system consisting of a chiral phosphoramidite ligand and Pd(dba)·CHCl causes the decarboxylation of 5-vinyloxazolidine-2,4-diones to generate amide-containing aza-π-allylpalladium 1,3-dipole intermediates, which are capable of triggering the dearomatization of 3-nitroindoles for diastereo- and enantioselective [3+2] cycloaddition, leading to the formation of a series of highly functionalized pyrroloindolines containing three contiguous stereogenic centers with excellent results (up to 99% yield, 88:12 dr, and 96% ee).

Thiol-Triggered Tandem Dearomative Michael Addition/Intramolecular Henry Reaction of 2-Nitrobenzofurans: Access to Sulfur-Containing Polyheterocyclic Compounds.

An efficient dearomative cyclization of 2-nitrobenzofurans via a thiol-triggered tandem Michael addition/intramolecular Henry reaction has been developed. A range of thiochromeno[3,2-]benzofuran-11-ols and tetrahydrothieno[3,2-]benzofuran-3-ols could be obtained in up to 99% yield and up to >20:1 dr. The valuable thiochromone fused benzofurans could be prepared with the reaction of 2-nitrobenzofurans and 2-mercaptobenzaldehyde via the tandem dearomative Michael addition/intramolecular Henry reaction/rearomatization/oxidative dehydrogenation process in a one-pot two-step operation.

Synthesis of Benzofuro[3,2-]indol-3-one Derivatives via Dearomative (3 + 2) Cycloaddition of 2-Nitrobenzofurans and -Quinamines.

An efficient dearomative (3 + 2) cycloaddition of -quinamines and 2-nitrobenzofurans has been developed. This reaction proceeds smoothly under mild conditions and affords a series of benzofuro[3,2-]indol-3-one derivatives in good to excellent yields (up to 98%) with perfect diastereoselectivities (all cases > 20:1 ). The scale-up synthesis and versatile derivatizations demonstrate the potential synthetic application of the protocol.

Facile Construction of Benzo[][1,3]oxazocine: Reductive Radical Dearomatization of -Alkyl Quinoline Quaternary Ammonium Salts.

Reductive radical dearomatization -alkyl quinoline quaternary ammonium salts to synthesize structurally complex and challenging polysubstituted benzo[][1,3]oxazocines was first reported. The mechanism showed various allyl alcohols can be converted into alkyl radicals under reduction conditions of iron/silane. These radicals then nucleophilically attack the C4 site of -alkyl quinoline quaternary ammonium salts, and intramolecular cyclization of the resulting intermediate generates the target product.

Cu-Catalyzed Direct Asymmetric Mannich Reaction of 2-Alkylazaarenes and Isatin-Derived Ketimines.

The first direct catalytic asymmetric Mannich reaction of 2-alkylazaarenes and ketimines was realized with a chiral Cu-bis(oxazoline) complex as the catalyst. The asymmetric addition of 2-alkylpyridines to isatin-derived ketimines proceeded smoothly to afford α,β-functionalized 2-substituted pyridines bearing 3-amino-3,3-disubstituted oxindole motifs with excellent results (≤99% yield, 99:1 dr, and 98% ee). The catalytic system was also extended to 2-alkylbenzothiazoles as nucleophiles for the asymmetric Mannich reaction of ketimines.

Constructing a Stable Conductive Network for High-Performance Silicon-Based Anode in Lithium-Ion Batteries.

The application of carbon nanotubes to silicon nanoparticles has been used to improve the electrical conductivity of silicon-carbon anodes and prevent agglomeration of silicon nanoparticles during cycling. In this study, the composites are synthesized through an uncomplicated technique that involves the ultrasonication mixing of pyrene derivatives and carbon nanotubes and the formation of complexes with silicon nanoparticles in ultrasonic dispersion and magnetic stirring and then treated under vacuum. When the prepared composites are applied as lithium-ion battery anodes, the Si@(POH-AOCNTs) electrode displays a high reversible capacity of 3254.

Development and Application of a Comprehensive Nontargeted Screening Strategy for Aristolochic Acid Analogues.

Aristolochic acid analogs (AAAs) are naturally occurring carcinogenic and toxic compounds that pose a safety threat to pharmaceuticals and the environment. It is challenging to screen AAAs due to their lack of characteristic mass spectral fragmentation and their presence of structural diversity. A comprehensive nontargeted screening strategy was proposed by taking into account diverse factors and incorporating various self-developed techniques, and a Python3-based toolkit called AAAs_finder was developed for its implementation.