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Non classé – Page 2 – ChemDigest

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Unlocking a (Pseudo)‐Mechanically Interlocked Molecule with a Coronene “Shoehorn”

Par / 23 mars 2023 / Non classé
Unlocking a (Pseudo)-Mechanically Interlocked Molecule with a Coronene “Shoehorn”

A mechanically interlocked molecule (MIM) comprising a tetragold metallobox and a tetraoctynyl-pyrene guest that can be regarded as a pseudo-metallosuit[4]ane is described. In contrast to other MIMs, the tetrasubstituted guest can be released from this molecule by the addition of coronene through a “shoehorning” mechanism.

Abstract

Mechanically interlocked molecules (MIMs) have gained increasing interest during the last decades, not only because of their aesthetic appeal, but also because their unique properties have allowed them to find applications in nanotechnology, catalysis, chemosensing and biomedicine. Herein we describe how a pyrene molecule with four octynyl substituents can be easily encapsulated within the cavity of a tetragold(I) rectangle-like metallobox, by template formation of the metallo-assembly in the presence of the guest. The resulting assembly behaves as a mechanically interlocked molecule (MIM), in which the four long limbs of the guest protrude from the entrances of the metallobox, thus locking the guest inside the cavity of the metallobox. The new assembly resembles a metallo-suit[4]ane, given the number of protruding long limbs and the presence of the metal atoms in the host molecule. However, unlike normal MIMs, this molecule can release the tetra-substituted pyrene guest by the addition of coronene, which can smoothly replace the guest in the cavity of the metallobox. Combined experimental and computational studies allowed the role of the coronene molecule in facilitating the release of the tetrasubstituted pyrene guest to be explained, through a process that we named “shoehorning”, as the coronene compresses the flexible limbs of the guest so that it can reduce its size to slide in and out the metallobox.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Susana Ibáñez, Katarzyna Świderek, Eduardo Peris
onlinelibrary.wiley.com/doi/10.1002/anie.202301914

N‐(Morpholine‐4‐dithio)phthalimide: A Shelf‐Stable, Bilateral Platform Molecule Enabling Access to Diverse Unsymmetrical Disulfides

Par / 23 mars 2023 / Non classé
N-(Morpholine-4-dithio)phthalimide: A Shelf-Stable, Bilateral Platform Molecule Enabling Access to Diverse Unsymmetrical Disulfides**

A shelf-stable and easy-to-prepare disulfurating reagent with chemoselectively displaceable amino and imide leaving groups is described. Protonation of this reagent promotes exclusive displacement of the amino group with various neutral carbon nucleophiles. The resulting dithiophthalimides are amenable to diverse substitution reactions under basic or neutral conditions, thus enabling expedient access to structurally diverse unsymmetrical disulfides.

Abstract

Synthetic methods for unsymmetrical disulfides are greatly needed owing to their applications in drug discovery, linker chemistry, and materials sciences. In this study, a new shelf-stable and easy-to-prepare bilateral disulfurating platform molecule, N-(morpholine-4-dithio)phthalimide, has been developed for the divergent synthesis of unsymmetrical disulfides. The amino and imide leaving groups of this reagent can be orthogonally transformed. Under acidic conditions, the amino moiety undergoes selective protonation and thus can be displaced by various carbon nucleophiles, such as allyl trimethylsilanes, alkynyl silanes, and electron-rich arenes, leaving the phthalimide moiety untouched. Meanwhile, the phthalimide leaving group is amenable to substitution under basic or neutral conditions. The combination of these transformations provides rapid access to diverse unsymmetrical disulfides through two C−S bond-forming reactions.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Hayato Asanuma, Kazuya Kanemoto, Tokiharu Watanabe, Shin‐ichi Fukuzawa
onlinelibrary.wiley.com/doi/10.1002/anie.202219156

Facile Synthesis and Chiral Resolution of Expanded Helicenes with up to 35 cata‐Fused Benzene Rings

Par / 23 mars 2023 / Non classé
Facile Synthesis and Chiral Resolution of Expanded Helicenes with up to 35 cata-Fused Benzene Rings**

Expanded helicenes with up to 35 cata-fused benzene rings can be synthesized by Suzuki-coupling-mediated oligomerization followed by bismuth(III)-triflate-catalyzed cyclization of vinyl ethers. Their chiroptical properties were also studied.

Abstract

Expanded helicenes are expected to show enhanced chiroptical properties as compared to the classical helicenes but the synthesis is very challenging. Herein, we report the facile synthesis of a series of expanded helicenes Hn (n=1–4) containing 11, 19, 27 and 35 cata-fused benzene rings through Suzuki coupling-based oligomerization followed by Bi(OTf)3-mediated regioselective cyclization of vinyl ethers. Their structures were determined by X-ray crystallographic analysis. Enantiopure H2, H3, and H4 can be isolated by chiral HPLC and they all exhibit strong chiroptical responses with high absorption dissymmetry factor (|gabs|) values (0.020 for H2, 0.021 for H3, and 0.021–0.024 for H4).

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Gui‐Fei Huo, Toshiya M. Fukunaga, Xudong Hou, Yi Han, Wei Fan, Shaofei Wu, Hiroyuki Isobe, Jishan Wu
onlinelibrary.wiley.com/doi/10.1002/anie.202218090

Modular Synthesis of a Tridecasaccharide Motif of Bacteroides vulgatus Lipopolysaccharides against Inflammatory Bowel Diseases through an Orthogonal One‐Pot Glycosylation Strategy

Par / 23 mars 2023 / Non classé
Modular Synthesis of a Tridecasaccharide Motif of Bacteroides vulgatus Lipopolysaccharides against Inflammatory Bowel Diseases through an Orthogonal One-Pot Glycosylation Strategy

A tridecasaccharide from Bacteroides vulgatus mpk lipopolysaccharides has been synthesized for the first time by a strategy involving orthogonal one-pot glycosylation reactions based on glycosyl ortho-(1-phenylvinyl)benzoates, which precluded issues such as aglycone transfer and the unpleasant odor of thioglycoside-based orthogonal one-pot glycosylation.

Abstract

Lipopolysaccharides from Bacteroides vulgatus represent interesting targets for the treatment of inflammatory bowel diseases. However, efficient access to long, branched and complex lipopolysaccharides remains challenging. Herein, we report the modular synthesis of a tridecasaccharide from Bacteroides vulgates through an orthogonal one-pot glycosylation strategy based on glycosyl ortho-(1-phenylvinyl)benzoates, which avoids the issues of thioglycoside-based one-pot synthesis. Our approach also features: 1) 5,7-O-di-tert-butylsilylene-directed glycosylation for stereoselective construction of the α-Kdo linkage; 2) hydrogen-bond-mediated aglycone delivery for the stereoselective formation of β-mannosidic bonds; 3) remote anchimeric assistance for stereoselective assembly of the α-fucosyl linkage; 4) several orthogonal one-pot synthetic steps and strategic use of orthogonal protecting groups to streamline oligosaccharide assembly; 5) convergent [1+6+6] one-pot synthesis of the target.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Yunqin Zhang, Leilei Wang, Qingli Zhou, Zuoshan Li, Dan Li, Caixia Yin, Xiufang Wang, Guozhi Xiao
onlinelibrary.wiley.com/doi/10.1002/anie.202301351

An n‐Type Polythiophene Derivative with Excellent Thermoelectric Performance

Par / 23 mars 2023 / Non classé
An n-Type Polythiophene Derivative with Excellent Thermoelectric Performance

An n-type non-fused-ring conjugated polymer is developed by introducing electron-withdrawing imide or cyano groups to each thiophene unit of polythiophene backbone. The resultant polymer shows low LUMO/HOMO energy levels and highly ordered crystallite structure, leading to excellent thermoelectric performance after n-doping.

Abstract

Typical n-type conjugated polymers are based on fused-ring electron-accepting building blocks. Herein, we report a non-fused-ring strategy to design n-type conjugated polymers, i.e. introducing electron-withdrawing imide or cyano groups to each thiophene unit of a non-fused-ring polythiophene backbone. The resulting polymer, n-PT1, shows low LUMO/HOMO energy levels of −3.91 eV/−6.22 eV, high electron mobility of 0.39 cm2 V−1 s−1 and high crystallinity in thin film. After n-doping, n-PT1 exhibits excellent thermoelectric performance with an electrical conductivity of 61.2 S cm−1 and a power factor (PF) of 141.7 μW m−1 K−2. This PF is the highest value reported so far for n-type conjugated polymers and this is the first time for polythiophene derivatives to be used in n-type organic thermoelectrics. The excellent thermoelectric performance of n-PT1 is due to its superior tolerance to doping. This work indicates that polythiophene derivatives without fused rings are low-cost and high-performance n-type conjugated polymers.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Sihui Deng, Changshuai Dong, Jian Liu, Bin Meng, Junli Hu, Yang Min, Hongkun Tian, Jun Liu, Lixiang Wang
onlinelibrary.wiley.com/doi/10.1002/anie.202216049

Multi‐Stimuli Responsive Luminescence and Domino Phase Transition of Hybrid Copper Halides with Nonlinear Optical Switching Behavior

Par / 23 mars 2023 / Non classé
Multi-Stimuli Responsive Luminescence and Domino Phase Transition of Hybrid Copper Halides with Nonlinear Optical Switching Behavior

A multi-stimuli responsive luminescent material has been developed that not only exhibits reversible photoluminescence conversion and nonlinear optical switching in response to thermal stimulus, but also observes peculiar crystal-phase-recognition induced domino-type single-crystal-to-single-crystal phase transition and mechanical force induced phase transition under concomitant emission-color change.

Abstract

Although phase transition materials (PTMs) under external stimuli are of great research interest duo to their rich potential applications, it is still challenging to explore multi-responsive PTMs. Herein, two different phases of organic–inorganic hybrid copper-based halides, α- and β-Gua3Cu2I5 (Gua+=CN3H6+), were synthesized by solvent evaporation method, which they crystalize in the noncentrosymmetric space group Fdd2 with zero-dimensional structure and centrosymmetric space group C2/c with one-dimensional metal-halogen framework, respectively. Interestingly, it is firstly demonstrated that Gua3Cu2I5 simultaneously possesses reversible PL conversion and NLO switching properties in response to thermal stimulus. Strikingly, apart from heat, its structural phase transition can also be triggered by crystalline-phase-recognition (CPR) and mechanical force. These new findings may pave a path for future exploration of PTMs with multiple physical properties.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Jiajing Wu, Yue Guo, Jing‐Li Qi, Wen‐Dong Yao, Su‐Xin Yu, Wenlong Liu, Sheng‐Ping Guo
onlinelibrary.wiley.com/doi/10.1002/anie.202301937

On the Discrepancy between Local and Average Structure in the Fast Na+ Ionic Conductor Na2.9Sb0.9W0.1S4

Par / 22 mars 2023 / Non classé

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Journal of the American Chemical Society

Journal of the American Chemical Society: Latest Articles (ACS Publications)
Authors: Oliver Maus, Matthias T. Agne, Till Fuchs, Paul S. Till, Björn Wankmiller, Josef Maximilian Gerdes, Rituraj Sharma, Michael Heere, Niina Jalarvo, Omer Yaffe, Michael Ryan Hansen, and Wolfgang G. Zeier
dx.doi.org/https://doi.org/10.1021/jacs.2c11803

Alternative Approach to the Large-Scale Synthesis of the Densely Functionalized Pyrrolidone BMT-415200

Par / 22 mars 2023 / Non classé

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Organic Process Research & Development
Organic Process Research & Development: Latest Articles (ACS Publications)

Authors: Souvik Rakshit, Shunmugaraj Sathasivam, Raghurami Reddy, Saladi V. Rao, Vijaykumar Shekarappa, Moorthy Kandasamy, Mohamed Jaleel, Saravanan Murugan, Anuradha Bhat, Tamilarasan Subramani, Thirumalai Lakshminarasimhan, Aravind Gangu, Steven R. Wisniewski, Nathaniel Kopp, Ian Hale, Jason M. Stevens, Victor W. Rosso, Martin D. Eastgate, and Rajappa Vaidyanathan
dx.doi.org/https://doi.org/10.1021/acs.oprd.3c00007

Synthetic Access to a Framework-Stabilized and Fully Sulfided Analogue of an Anderson Polyoxometalate that is Catalytically Competent for Reduction Reactions

Par / 22 mars 2023 / Non classé

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Journal of the American Chemical Society

Journal of the American Chemical Society: Latest Articles (ACS Publications)
Authors: Jiaxin Duan, Hafeera Shabbir, Zhihengyu Chen, Wentuan Bi, Qin Liu, Jingyi Sui, Luka Đorđević, Samuel I. Stupp, Karena W. Chapman, Alex B. F. Martinson, Alice Li, Richard D. Schaller, Subhadip Goswami, Rachel B. Getman, and Joseph T. Hupp
dx.doi.org/https://doi.org/10.1021/jacs.2c12992

Asymmetric Synthesis of Spiropyrazolone-Fused Dihydrofuran-naphthoquinones Bearing Contiguous Stereocenters via a Michael Addition/Chlorination/Nucleophilic Substitution Sequence

Par / 22 mars 2023 / Non classé

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The Journal of Organic Chemistry

The Journal of Organic Chemistry: Latest Articles (ACS Publications)
Authors: Gaihui Li, Hongyu Zhang, Guoshun Zhang, Bei Wei, Bin Liu, Heng Song, Qingshan Li, and Shurong Ban
dx.doi.org/https://doi.org/10.1021/acs.joc.2c03013

A Systematic Study on the Effects of Solvating Solvents and Additives in Localized High‐Concentration Electrolytes over Electrochemical Performance of Lithium‐Ion Batteries

Par / 21 mars 2023 / Non classé
A Systematic Study on the Effects of Solvating Solvents and Additives in Localized High-Concentration Electrolytes over Electrochemical Performance of Lithium-Ion Batteries

The effects of microscopic solvation structure, solvating solvent and additive of localized high-concentration electrolytes (LHCEs) over the electrolyte properties, the electrode/electrolyte interphases and the cycling stability of lithium-ion batteries (LIBs) were systematically studied. The synergetic decomposition of anion, proper solvent and additive in LHCEs is the key to forming effective interphases and achieving long cycle life of LIBs.

Abstract

Localized high-concentration electrolytes (LHCEs) based on five different types of solvents were systematically studied and compared in lithium (Li)-ion batteries (LIBs). The unique solvation structure of LHCEs promotes the participation of Li salt in forming solid electrolyte interphase (SEI) on graphite (Gr) anode, which enables solvents previously considered incompatible with Gr to achieve reversible lithiation/delithiation. However, the long cyclability of LIBs is still subject to the intrinsic properties of the solvent species in LHCEs. Such issue can be readily resolved by introducing a small amount of additive into LHCEs. The synergetic decompositions of Li salt, solvating solvent and additive yield effective SEIs and cathode electrolyte interphases (CEIs) in most of the studied LHCEs. This study reveals that both the structure and the composition of solvation sheaths in LHCEs have significant effect on SEI and CEI, and consequently, the cycle life of energetically dense LIBs.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Hao Jia, Ju‐Myung Kim, Peiyuan Gao, Yaobin Xu, Mark H. Engelhard, Bethany E. Matthews, Chongmin Wang, Wu Xu
onlinelibrary.wiley.com/doi/10.1002/anie.202218005

Type Ι Photosensitizer Targeting G‐Quadruplex RNA Elicits Augmented Immunity for Cancer Ablation

Par / 21 mars 2023 / Non classé
Type Ι Photosensitizer Targeting G-Quadruplex RNA Elicits Augmented Immunity for Cancer Ablation

A near-infrared (NIR) type Ι photosensitizer (PS), BAMA, was developed using an acridinium scaffold that enables efficient O2⋅− production upon targeting G-quadruplexes (G4s). It was employed for imaging and effective photodynamic therapy (PDT) of an immunogenic cold tumor with bolstered antitumor immunity, raising the possibility of developing efficient PDT through ablation of functional RNAs for cancer therapy.

Abstract

Type Ι photodynamic therapy (PDT) represents a promising treatment modality for tumors with intrinsic hypoxia. However, type Ι photosensitizers (PSs), especially ones with near infrared (NIR) absorption, are limited and their efficacy needs improvement via new targeting tactics. We develop a NIR type Ι PS by engineering acridinium derived donor-π-acceptor systems. The PS exhibits an exclusive type Ι PDT mechanism due to effective intersystem crossing and disfavored energy transfer to O2, and shows selective binding to G-quadruplexes (G4s) via hydrogen bonds identified by a molecular docking study. Moreover, it enables fluorogenic detection of G4s and efficient O2⋅− production in hypoxic conditions, leading to immunogenic cell death and substantial variations of gene expression in RNA sequencing. Our strategy demonstrates augmented antitumor immunity for effective ablation of immunogenic cold tumor, highlighting its potential of RNA-targeted type Ι PDT in precision cancer therapy.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Wen Chen, Yuan Zhang, Hai‐Bo Yi, Fenglin Wang, Xia Chu, Jian‐Hui Jiang
onlinelibrary.wiley.com/doi/10.1002/anie.202300162

Ultra‐Fast Preparation of Large‐Area Graphdiyne‐Based Membranes via Alkynylated Surface‐Modification for Nanofiltration

Par / 21 mars 2023 / Non classé
Ultra-Fast Preparation of Large-Area Graphdiyne-Based Membranes via Alkynylated Surface-Modification for Nanofiltration

Hydrogen-substituted graphdiyne (HsGDY)-based membranes are prepared on alkynylated commercial ceramic tubes, overcoming the limitation that such layers could be synthesized only on a limited number of metal surfaces. The prepared HsGDY layers are strongly attached to the ceramic surface and exhibit excellent molecular permselectivity and ultra-high water permeance due to the unique surface properties and unusual conjugated structure.

Abstract

Graphdiynes (GDYs), two-dimensional graphene-like carbon systems, are considered as potential advanced membrane material due to their unique physicochemical features. Nevertheless, the scale-up of integrated GDY membranes is technologically challenging, and most studies remain at the theoretical stage. Herein, we report a simple and efficient alkynylated surface-mediated strategy to prepare hydrogen-substituted graphdiyne (HsGDY) membranes on commercial alumina tubes. Surface alkynylation initiates an accelerated surface-confined coupling reaction in the presence of a copper catalyst and facilitates the nanoscale epitaxial lateral growth of HsGDY. A continuous and ultra-thin HsGDY membrane (∼100 nm) can be produced within 15 min. The resulting membranes exhibit outstanding molecular sieving together with excellent water permeances (ca. 1100 L m−2 h−1 MPa−1), and show a long-term durability in cross-flow nanofiltration, owing to the superhydrophilic surface and hydrophobic pore walls.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Xingda Yang, Zhou Qu, Sen Li, Manhua Peng, Chunxi Li, Ruimao Hua, Hongwei Fan, Jürgen Caro, Hong Meng
onlinelibrary.wiley.com/doi/10.1002/anie.202217378

Chemoproteomic and Transcriptomic Analysis Reveals that O‐GlcNAc Regulates Mouse Embryonic Stem Cell Fate through the Pluripotency Network

Par / 21 mars 2023 / Non classé
Chemoproteomic and Transcriptomic Analysis Reveals that O-GlcNAc Regulates Mouse Embryonic Stem Cell Fate through the Pluripotency Network

Many pluripotency transcription factors (PTFs) were found to be O-GlcNAcylated in mouse embryonic stem cells (mESCs) and the O-GlcNAcylation stoichiometry at various modification sites suppressed during differentiation. Mechanistically, O-GlcNAc acts at the PTF network level and inhibition of O-GlcNAcylation enhances the expression of neuronal lineage-specific genes, promoting mESC-derived neuronal differentiation.

Abstract

Self-renewal and differentiation of embryonic stem cells (ESCs) are influenced by protein O-linked β-N-acetylglucosamine (O-GlcNAc) modification, but the underlying mechanism remains incompletely understood. Herein, we report the identification of 979 O-GlcNAcylated proteins and 1340 modification sites in mouse ESCs (mESCs) by using a chemoproteomics method. In addition to OCT4 and SOX2, the third core pluripotency transcription factor (PTF) NANOG was found to be modified and functionally regulated by O-GlcNAc. Upon differentiation along the neuronal lineage, the O-GlcNAc stoichiometry at 123 sites of 83 proteins—several of which were PTFs—was found to decline. Transcriptomic profiling reveals 2456 differentially expressed genes responsive to OGT inhibition during differentiation, of which 901 are target genes of core PTFs. By acting on the core PTF network, suppression of O-GlcNAcylation upregulates neuron-related genes, thus contributing to mESC fate determination.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Yi Hao, Xiang Li, Ke Qin, Yujie Shi, Yanwen He, Che Zhang, Bo Cheng, Xiwen Zhang, Guangyu Hu, Shuyu Liang, Qi Tang, Xing Chen
onlinelibrary.wiley.com/doi/10.1002/anie.202300500

Phase Instability in van der Waals In2Se3 Determined by Surface Coordination

Par / 21 mars 2023 / Non classé
Phase Instability in van der Waals In2Se3 Determined by Surface Coordination

Description: A mixture of experimental and theoretical approaches reveals that the ambient stability of 2D In2Se3 strongly depends on the surface coordination. Tetrahedral-coordinated surfaces were found to be more stable and suitable for device applications.

Abstract

van der Waals In2Se3 has attracted significant attention for its room-temperature 2D ferroelectricity/antiferroelectricity down to monolayer thickness. However, instability and potential degradation pathway in 2D In2Se3 have not yet been adequately addressed. Using a combination of experimental and theoretical approaches, we here unravel the phase instability in both α- and β′-In2Se3 originating from the relatively unstable octahedral coordination. Together with the broken bonds at the edge steps, it leads to moisture-facilitated oxidation of In2Se3 in air to form amorphous In2Se3−3xO3x layers and Se hemisphere particles. Both O2 and H2O are required for such surface oxidation, which can be further promoted by light illumination. In addition, the self-passivation effect from the In2Se3−3xO3x layer can effectively limit such oxidation to only a few nanometer thickness. The achieved insight paves way for better understanding and optimizing 2D In2Se3 performance for device applications.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Shanru Yan, Chao Xu, Cenchen Zhong, Yancong Chen, Xiangli Che, Xin Luo, Ye Zhu
onlinelibrary.wiley.com/doi/10.1002/anie.202300302