Shared posts

02 Sep 19:12

[ASAP] Descriptors Affecting Methane Selectivity in CO2 Hydrogenation over Unpromoted Bulk Iron(III)-Based Catalysts

by Andrey S. Skrypnik, Sergey A. Petrov, Vita A. Kondratenko, Qingxin Yang, Henrik Lund, Alexander A. Matvienko, and Evgenii V. Kondratenko

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ACS Catalysis
DOI: 10.1021/acscatal.2c03375
19 Jan 18:56

Confinement synthesis in porous molecule-based materials: a new opportunity for ultrafine nanostructures

Chem. Sci., 2022, 13,1569-1593
DOI: 10.1039/D1SC05983A, Review Article
Open Access Open Access
Li-Ming Cao, Jia Zhang, Xue-Feng Zhang, Chun-Ting He
The space-, coordination-, and/or ion-confinement in porous molecule-based materials (PMMs) endow the PMM-confinement (pyrolysis) synthesis to construct a variety of ultrafine nanostructures.
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24 Sep 14:11

[ASAP] Cu-Catalyzed Cross-Coupling of Nitroarenes with Aryl Boronic Acids to Construct Diarylamines

by Xinyu Guan, Haoran Zhu, and Tom G. Driver

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ACS Catalysis
DOI: 10.1021/acscatal.1c03113
28 Apr 19:44

Construction of Hybrid Bi‐microcompartments with Exocytosis‐Inspired Behavior toward Fast Temperature‐Modulated Transportation of Living Organisms

by Haixu Chen, Lei Wang, Shengliang Wang, Junbo Li, Zhenhui Li, Youping Lin, Xiaoliang Wang, Xin Huang
Construction of Hybrid Bi-microcompartments with Exocytosis-Inspired Behavior toward Fast Temperature-Modulated Transportation of Living Organisms

The exocytosis-inspired behaviour was demonstrated in a temperature sensitive hybrid bi-microcompartment system. Due to the universal loading capacity and excellent biocompatibility, the proliferation and temperature-programmed fast release of living cells were realized, which provided a robust platform for the on-demand transportation of various living organisms.


Abstract

Inspired by the unique characteristics of living cells, the creation of life-inspired functional ensembles is a rapidly expanding research topic, enabling transformative applications in various disciplines. Herein, we report a facile method for the fabrication of phospholipid and block copolymer hybrid bi-microcompartments via spontaneous asymmetric assembly at the water/tributyrin interface, whereby the temperature-mediated dewetting of the inner microcompartments allowed for exocytosis to occur in the constructed system. The exocytosis location and commencement time could be controlled by the buoyancy of the inner microcompartment and temperature, respectively. Furthermore, the constructed bi-microcompartments showed excellent biocompatibility and a universal loading capacity toward cargoes of widely ranging sizes; thus, the proliferation and temperature-programmed transportation of living organisms was achieved. Our results highlight opportunities for the development of complex mesoscale dynamic ensembles with life-inspired behaviors and provide a novel platform for on-demand transport of various living organisms.

23 Apr 14:51

C(sp3)-H methylation enabled by peroxide photosensitization and Ni-mediated radical coupling

by Vasilopoulos, A., Krska, S. W., Stahl, S. S.

The "magic methyl" effect describes the change in potency, selectivity, and/or metabolic stability of a drug candidate associated with addition of a single methyl group. We report a synthetic method that enables direct methylation of C(sp3)–H bonds in diverse drug-like molecules and pharmaceutical building blocks. Visible light–initiated triplet energy transfer promotes homolysis of the O–O bond in di-tert-butyl or dicumyl peroxide under mild conditions. The resulting alkoxyl radicals undergo divergent reactivity, either hydrogen-atom transfer from a substrate C–H bond or generation of a methyl radical via β-methyl scission. The relative rates of these steps may be tuned by varying the reaction conditions or peroxide substituents to optimize the yield of methylated product arising from nickel-mediated cross-coupling of substrate and methyl radicals.

20 Apr 19:45

[ASAP] Methane C–H Activation by [Cu2O]2+ and [Cu3O3]2+ in Copper-Exchanged Zeolites: Computational Analysis of Redox Chemistry and X-ray Absorption Spectroscopy

by Olabisi Suleiman, Dipak Panthi, Olajumoke Adeyiga, and Samuel O. Odoh

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Inorganic Chemistry
DOI: 10.1021/acs.inorgchem.0c03693
17 Sep 19:54

[ASAP] Selective Construction of Diverse Polycyclic Spirooxindoles via a Three-Component Reaction of Cyclic Mercapto-Substituted β-Enamino Esters, Isatins, and Cyclic 1,3-Diketones

by Quan-Shun Sun, Jing Sun, Liu-Na Pan, and Chao-Guo Yan

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The Journal of Organic Chemistry
DOI: 10.1021/acs.joc.0c01290
07 Jul 21:14

[ASAP] Pd(II)-Catalyzed Enantioselective ?-C(sp3)–H Functionalizations of Free Cyclopropylmethylamines

by Zhe Zhuang and Jin-Quan Yu*

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Journal of the American Chemical Society
DOI: 10.1021/jacs.0c04801
26 Jun 14:55

Cycling between Molybdenum‐Dinitrogen and ‐Nitride Complexes to Support the Reaction Pathway for Catalytic Formation of Ammonia from Dinitrogen

by Yoshiaki Nishibayashi, Kazuya Arashiba, Hiromasa Tanaka, Kazunari Yoshizawa
Cycling between Molybdenum‐Dinitrogen and ‐Nitride Complexes to Support the Reaction Pathway for Catalytic Formation of Ammonia from Dinitrogen

Cycling between molybdenum(I)‐dinitrogen and molybdenum(IV)‐nitride complexes was investigated under ambient reaction conditions. A kinetic study of the second‐order reaction rate for the conversion of the molybdenum‐dinitrogen complex into the molybdenum‐nitride complex indicates that the formation of the dinitrogen‐bridged dimolybdenum complex is involved in the rate‐determining step. A new modified reaction pathway has been proposed based on the findings of our experimental and theoretical results.


Abstract

Cycling between molybdenum(I)‐dinitrogen and molybdenum(IV)‐nitride complexes was investigated under ambient reaction conditions. A kinetic study of the second‐order reaction rate for the conversion of the molybdenum‐dinitrogen complex into the molybdenum‐nitride complex indicates that the formation of the dinitrogen‐bridged dimolybdenum complex is involved in the rate‐determining step. DFT calculations indicate that the molybdenum‐dinitrogen complex transforms into the molybdenum‐nitride complex via direct cleavage of the nitrogen‐nitrogen triple bond of the bridging dinitrogen ligand of the dinitrogen‐bridged dimolybdenum complex. The corresponding reaction of the molybdenum‐nitride complex transforming into the molybdenum‐dinitrogen complex proceeds via the ligand exchange of ammonia for dinitrogen at the dinitrogen‐bridged dimolybdenum complexes. A new modified reaction pathway has been proposed based on the findings of our experimental and theoretical results.

20 Feb 14:19

[ASAP] Probing Al Distribution in LiCo0.96Al0.04O2 Materials Using 7Li, 27Al, and 59Co MAS NMR Combined with Synchrotron X-ray Diffraction

by Marie Duffiet†‡, Maxime Blangero‡, Pierre Etienne Cabelguen§, Kyeong Se Song‡, Franc¸ois Fauth?, Claude Delmas†, and Dany Carlier*†

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Inorganic Chemistry
DOI: 10.1021/acs.inorgchem.9b03260
19 Nov 13:45

Temperature-dependent polarization in a non-polar crystal

by Gustau Catalan

Nature, Published online: 18 November 2019; doi:10.1038/d41586-019-03494-4

A crystal’s surface has been found to behave as a distinct material that has temperature-dependent electrical polarization — despite the rest of the crystal being non-polar.
29 Oct 14:54

The race is on to repurpose garbage

by Marc S. Reisch
Despite a spotty track record, companies keep trying to convert trash into energy, fuels, and chemicals
05 Aug 13:15

Ni-catalyzed cross-electrophile coupling between vinyl/aryl and alkyl sulfonates: synthesis of cycloalkenes and modification of peptides

Chem. Sci., 2019, 10,8706-8712
DOI: 10.1039/C9SC03347E, Edge Article
Open Access Open Access
Jicheng Duan, Yun-Fei Du, Xiaobo Pang, Xing-Zhong Shu
We report a reductive coupling between C–O electrophiles, providing an efficient approach to the synthesis of aliphatic cycloalkenes and late-stage modification of peptides.
The content of this RSS Feed (c) The Royal Society of Chemistry
10 May 14:47

Organocopper cross-coupling reaction for C–C bond formation on highly sterically hindered structures

Chem. Sci., 2019, 10,6107-6112
DOI: 10.1039/C9SC00891H, Edge Article
Open Access Open Access
Creative Commons Licence&nbsp This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Miku Oi, Ryo Takita, Junichiro Kanazawa, Atsuya Muranaka, Chao Wang, Masanobu Uchiyama
A potent cross-coupling methodology that enables efficient carbon–carbon bond formation at sterically hindered sp2- and sp3-carbons has been developed.
The content of this RSS Feed (c) The Royal Society of Chemistry
30 Apr 22:11

[ASAP] Generic Ion Chromatography–Conductivity Detection Method for Analysis of Palladium Scavengers in New Drug Substances

by Lanfang Zou, Raffeal Bennett, Imad A. Haidar Ahmad, Brandon M. Jocher, Li Zhang, Xiaodong Bu, Ian Mangion, Erik L. Regalado

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Organic Process Research & Development
DOI: 10.1021/acs.oprd.9b00101
12 Feb 18:09

[ASAP] Development of a Terpene Feedstock-Based Oxidative Synthetic Approach to the Illicium Sesquiterpenes

by Kevin Hung, Matthew L. Condakes, Luiz F. T. Novaes, Stephen J. Harwood, Takahiro Morikawa, Zhi Yang, Thomas J. Maimone

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Journal of the American Chemical Society
DOI: 10.1021/jacs.8b12247
12 Feb 18:08

[ASAP] Graphene Nanoribbons Derived from Zigzag Edge-Encased Poly(para-2,9-dibenzo[bc,kl]coronenylene) Polymer Chains

by Doreen Beyer, Shiyong Wang, Carlo A. Pignedoli, Jason Melidonie, Bingkai Yuan, Can Li, Jan Wilhelm, Pascal Ruffieux, Reinhard Berger, Klaus Müllen, Roman Fasel, Xinliang Feng

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Journal of the American Chemical Society
DOI: 10.1021/jacs.8b10407
12 Feb 18:08

Dynamic Kinetic Resolution of Aldehydes by Hydroacylation

by Zhiwei Chen, Yusuke Aota, Hillary My Ha Nguyen, Vy Dong
Angewandte Chemie International Edition Dynamic Kinetic Resolution of Aldehydes by Hydroacylation

Dynamic duo: Racemic α‐allyl aldehydes undergo stereoconvergent hydroacylation to generate α,γ‐disubstituted cyclopentanones with high diastereo‐ and enantioselectivities. In this dynamic kinetic resolution, a primary amine catalyst racemizes the aldehyde substrate via enamine formation and hydrolysis while a rhodium catalyst promotes cyclization.


Abstract

We report a dynamic kinetic resolution (DKR) of chiral 4‐pentenals by olefin hydroacylation. A primary amine racemizes the aldehyde substrate via enamine formation and hydrolysis. Then, a cationic rhodium catalyst promotes hydroacylation to generate α,γ‐disubstituted cyclopentanones with high enantio‐ and diastereoselectivities.

12 Feb 18:08

Bifluoride Ion Mediated SuFEx Trifluoromethylation of Sulfonyl Fluorides and Iminosulfur Oxydifluorides

by Christopher J. Smedley, Qinheng Zheng, Bing Gao, Suhua Li, Andrew Molino, Hendrika M. Duivenvoorden, Belinda S. Parker, David J. D. Wilson, K. Barry Sharpless, John Edward Moses
Angewandte Chemie International Edition Bifluoride Ion Mediated SuFEx Trifluoromethylation of Sulfonyl Fluorides and Iminosulfur Oxydifluorides

An expedient SuFEx trifluoromethylation of sulfonyl fluorides and iminosulfur oxyfluorides is described. The efficient S−F exchange with TMSCF3 is initiated by sub‐stoichiometric quantities of bifluoride ion [FHF] in anhydrous DMSO. The selective anticancer properties of previously inaccessible bis(trifluoromethyl)sulfur oxyimines are also demonstrated.


Abstract

SuFEx is a new‐generation click chemistry transformation that exploits the unique properties of S−F bonds and their ability to undergo near‐perfect reactions with nucleophiles. We report here the first SuFEx‐based procedure for the efficient synthesis of pharmaceutically important triflones and bis(trifluoromethyl)sulfur oxyimines from sulfonyl fluorides and iminosulfur oxydifluorides, respectively. The new process involves rapid S−F exchange with trifluoromethyltrimethylsilane (TMSCF3) upon activation by potassium bifluoride in anhydrous DMSO. The reaction tolerates a wide selection of substrates and proceeds under mild conditions without need for chromatographic purification. A tentative mechanism is proposed involving nucleophilic displacement of S−F by the trifluoromethyl anion via a five‐coordinate intermediate. The utility of late‐stage SuFEx trifluoromethylation is demonstrated through the synthesis and selective anticancer properties of a bis(trifluoromethyl)sulfur oxyimine.

12 Feb 18:07

New Platforms for Stable Carbon‐Centered Radicals

by Atsuhiro Osuka, Kenichi Kato

Organic radicals can play important roles potentially in diverse functional materials owing to an unpaired electron but are usually highly reactive and difficult to use. Therefore, stabilization of organic radicals is crucially important. Among organic radicals, carbon‐centered radicals are promising because of their trivalent nature that enables structural diversity and elaborate designs but they show less stabilities because of reactivities toward carbon‐carbon bond formation and atmospheric oxygen. Recently, stable carbon‐centered radicals have been increasingly explored on the basis of diverse molecular platforms. This minireview highlights these newly explored stable carbon‐centered radicals with a particular focus on porphyrinoid‐stabilized radicals owing to their remarkable spin delocalization abilities.

03 Feb 21:40

[ASAP] Synthesis, Structures, and Magnetic Properties of Two Coordination Assemblies of Mn(III) Single Molecule Magnets Bridged via Photochromic Diarylethene Ligands

by Ahmed Fetoh, Goulven Cosquer, Masakazu Morimoto, Masahiro Irie, Ola El-Gammal, Gaber M. Abu El-Reash, Brian K. Breedlove, Masahiro Yamashita

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Inorganic Chemistry
DOI: 10.1021/acs.inorgchem.8b02578
30 Dec 17:51

[ASAP] Solid-State Order and Charge Mobility in [5]- to [12]Cycloparaphenylenes

by Janice B. Lin, Evan R. Darzi, Ramesh Jasti, Ilhan Yavuz, K. N. Houk

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Journal of the American Chemical Society
DOI: 10.1021/jacs.8b10699
14 Nov 18:38

Intertwined Titanium Carbide MXene within a 3 D Tangled Polypyrrole Nanowires Matrix for Enhanced Supercapacitor Performances

by Hyoyoung Lee, Thi Anh Le, Ngoc Quang Tran, Yeseul Hong
Chemistry – A European Journal Intertwined Titanium Carbide MXene within a 3 D Tangled Polypyrrole Nanowires Matrix for Enhanced Supercapacitor Performances

Electrode architecture: Intertwined titanium carbide MXene within a tangled polypyrrole nanowire matrix is prepared and demonstrated as a novel hybridization electrode with outstanding gravimetric capacitance (610 F g−1) and stability (14 000 cycles) compared with reported MXene‐based supercapacitors (see figure).


Abstract

The exploration of the rational design and synthesis of unique and robust architectured electrodes for the high capacitance, rate capability, and stability of supercapacitors is crucial to the future of energy storage technology. Herein, an in situ synthesis of multilayered titanium carbide MXene tightly caging within a 3 D conducting tangled polypyrrole (PPy) nanowire (NW) network is proposed as an effective strategy to prevent the aggregation of MXene, profoundly enhancing the electrochemical performance of the supercapacitor. Owing to the beneficial effects of an ideal 3 D interconnected porous structure and high electrical conductivity, the obtained electrode exhibits fast charge and ion transport kinetics as well as full usage of active material. As expected, the 3 D Ti3C2T x @PPY NW exhibits a specific capacitance five times higher than that of pristine MXene (610 F g−1), a good rate capability up to a current density of 25 A g−1, and excellent stability with 100 % retention after 14 000 cycles at 4 A g−1, outperforming the known state‐of‐the‐art MXene‐based supercapacitor. Our work provides a facile method for enhancing the performance of MXene‐based energy storage devices.

26 Apr 21:23

Catalytic enantioselective Minisci-type addition to heteroarenes

by Proctor, R. S. J., Davis, H. J., Phipps, R. J.

Basic heteroarenes are a ubiquitous feature of pharmaceuticals and bioactive molecules, and Minisci-type additions of radical nucleophiles are a leading method for their elaboration. Despite many Minisci-type protocols that result in the formation of stereocenters, exerting control over the absolute stereochemistry at these centers remains an unmet challenge. We report a process for addition of prochiral radicals, generated from amino acid derivatives, to pyridines and quinolines. Our method offers excellent control of both enantioselectivity and regioselectivity. An enantiopure chiral Brønsted acid catalyst serves both to activate the substrate and induce asymmetry, while an iridium photocatalyst mediates the required electron transfer processes. We anticipate that this method will expedite access to enantioenriched small-molecule building blocks bearing versatile basic heterocycles.

19 Mar 12:05

[ASAP] A General Strategy for Aliphatic C–H Functionalization Enabled by Organic Photoredox Catalysis

by Kaila A. Margrey, William L. Czaplyski, David A. Nicewicz and Erik J. Alexanian

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Journal of the American Chemical Society
DOI: 10.1021/jacs.8b00592
13 Dec 19:35

Membrane-Coated ElectrocatalystsAn Alternative Approach To Achieving Stable and Tunable Electrocatalysis

by Daniel V. Esposito

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ACS Catalysis
DOI: 10.1021/acscatal.7b03374
28 Jun 05:27

An Inverse Michaelis–Menten Approach for Interfacial Enzyme Kinetics

by Jeppe Kari, Morten Andersen, Kim Borch and Peter Westh

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ACS Catalysis
DOI: 10.1021/acscatal.7b00838
18 Feb 05:04

Senate confirms Scott Pruitt to lead EPA

by Jessica Morrison
Uncertainty surrounds agency as Oklahoma attorney general readies to take the helm
31 Oct 00:31

Iron-Catalyzed Cyclization of Nitrones with Geminal-Substituted Vinyl Acetates: A Direct [4 + 2] Assembly Strategy Leading to 2,4-Disubstituted Quinolines

by Mingbing Zhong, Song Sun, Jiang Cheng and Ying Shao

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The Journal of Organic Chemistry
DOI: 10.1021/acs.joc.6b01910
30 Sep 20:59

Enantioselective Cu-Catalyzed Arylation of Secondary Phosphine Oxides with Diaryliodonium Salts toward the Synthesis of P-Chiral Phosphines

by Rodolphe Beaud, Robert J. Phipps and Matthew J. Gaunt

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Journal of the American Chemical Society
DOI: 10.1021/jacs.6b09334