Mois : avril 2020

Mesoscale coordination constructs

Nature Chemistry, Published online: 28 April 2020; doi:10.1038/s41557-020-0461-0A series of mesoscale supramolecular hexagonal grids have been constructed in solution through stepwise intra- then intermolecular coordination-driven self-assembly, and characterized with atomic resolution by scanning tunnelling microscopy and spectroscopy.Authors: Ruoning

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Ultrafast control of anisotropy

Nature Chemistry, Published online: 28 April 2020; doi:10.1038/s41557-020-0462-zSingle-molecule magnets are able to store information through their magnetic anisotropy, making them very promising systems for memory applications. Now, femtosecond-laser-initiated molecular dynamics that modulate magnetic anisotropy have been observed, paving the way for operation on ultrafast timescales.Authors: Eric

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Facile One-Pot Access to α-Diazo-β-ketosulfones from Sulfonyl Chlorides and α-Haloketones

doi.org/10.1055/s-0040-1707525

Synthesis
DOI: 10.1055/s-0040-1707525

A convenient one-pot approach to the preparation of α-diazo-β-ketosulfones from sulfonyl chlorides is described. It involves the conversion of the sulfonyl chloride to sodium sulfinate, alkylation of the latter with α-haloketones followed by diazo transfer using the ‘sulfonyl-azide-free’ (‘SAFE’) protocol in aqueous medium. The simple and expedient method relies on readily available starting materials and provides facile access to a wide variety of valuable diazo reagents for organic synthesis.
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© Georg Thieme Verlag Stuttgart · New York

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Authors: Dar’in, Dmitry

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Efficient Kinetic Data Acquisition and Model Prediction: Continuous Flow Microreactors, Inline Fourier Transform Infrared Spectroscopy, and Self-Modeling Curve Resolution

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Organic Process Research & Development

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

Authors: Verena Fath†‡, Philipp Lau§, Christoph Greve§, Norbert Kockmann†, and Thorsten Ro¨der*‡
feedproxy.google.com/~r/acs/oprdfk/~3/4UAdgHD_FJ0/acs.oprd.0c00037

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Discovery of CPI-1612: A Potent, Selective, and Orally Bioavailable EP300/CBP Histone Acetyltransferase Inhibitor

feedproxy.google.com/~r/acs/amclct/~3/x9ZP8aYgiN8/acsmedchemlett.0c00155

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ACS Medicinal Chemistry Letters

Authors: Jonathan E. Wilson*†, Gaurav Patel?, Chirag Patel?, Francois Brucelle†‡, Annissa Huhn†§, Anna S. Gardberg†, Florence Poy†, Nico Cantone†, Archana Bommi-Reddy†, Robert J. Sims, III†?, Richard T. Cummings†, and Julian R. Levell†

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Transition-Metal-Free, Intermolecular Azidoheteroarylation of Alkenes: Efficient Access to β-Azidoalkylated Quinoxalinones and Preliminary Antifungal Evaluation Against Magnaporthe grisea

doi.org/10.1055/s-0040-1707514

Synthesis
DOI: 10.1055/s-0040-1707514

An efficient, PhI(OAc)2-mediated, radical azidoheteroarylation of alkenes under transition-metal-free conditions is reported by employing TMSN3 and quinoxalin-2(1H)-ones as coupling partners. This domino reaction allows an efficient synthesis of valuable orangoazides containing quinoxalin-2(1H)-one derivatives and could be extended to phosphinyl-alkylated quinoxalin-2(1H)-one in a single step in moderate to excellent yields under mild conditions, as demonstrated by the preliminary antibacterial evaluation against Magnaporthe grisea for the first time. Mechanistic studies revealed that this transformation undergoes a cascade addition pathway controlled by a polar radical.
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© Georg Thieme Verlag Stuttgart · New York

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Authors: Du, Yiming

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A Straightforward Synthesis of N-Substituted Ureas from Primary Amides

doi.org/10.1055/s-0040-1707103

Synthesis
DOI: 10.1055/s-0040-1707103

A direct and convenient method for the preparation of N-substituted ureas is achieved by treating primary amides with phenyliodine diacetate (PIDA) in the presence of an ammonia source (NH3 or ammonium carbamate) in MeOH. The use of 2,2,2-trifluoroethanol (TFE) as the solvent increases the electrophilicity of the hypervalent iodine species and allows the synthesis of electron-poor carboxamides. This transformation involves a nucleophilic addition of ammonia on the isocyanate intermediate generated in situ by a Hofmann rearrangement of the starting amide.
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© Georg Thieme Verlag Stuttgart · New York

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Authors: Saraiva Rosa, Nathalie

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Allyl 4-Chlorophenyl Sulfone as a Versatile 1,1-Synthon for Sequential α-Alkylation/Cobalt-Catalyzed Allylic Substitution

doi.org/10.1055/s-0040-1707524

Synthesis
DOI: 10.1055/s-0040-1707524

Despite their unique potential as rare 1,1-dipole synthons, allyl sulfones are rarely used in target-oriented syntheses, likely due to the lack of a general catalytic method for their branch-selective allylic substitution. Herein, we identified allyl 4-chlorophenyl sulfone as a versatile linchpin for both base-mediated α-derivatization and subsequent cobalt-catalyzed allylic substitution. The sequential transformations allow for highly regioselective access to branched allylic substitution products with a variety of aliphatic side chains. The photoredox-enabled­ ­cobalt catalysis is indispensable for achieving high yields and regioselectivity­ for the desulfonylative substitution in contrast to traditional metal-catalyzed protocols, which lead to inferior outcomes in the corresponding transformations.
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© Georg Thieme Verlag Stuttgart · New York

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Authors: Sekino, Tomoyuki

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Update to Our Reader, Reviewer, and Author Communities—April 2020

feedproxy.google.com/~r/acs/amclct/~3/u9CggUjsOUA/acsmedchemlett.0c00206

ACS Medicinal Chemistry Letters

Authors: Cynthia J. Burrows(Editor-in-Chief, Accounts of Chemical Research), Shu Wang(Deputy Editor, ACS Applied Bio Materials), Hyun Jae Kim(Deputy Editor, ACS Applied Electronic Materials), Gerald J. Meyer(Deputy Editor, ACS Applied Energy Materials), Kirk Schanze(Editor-in-Chief, ACS Applied Materials & Interfaces, ACS Applied Bio Materials, ACS Applied Electronic Materials, ACS Applied Energy Materials, ACS Applied Nano Materials, and ACS Applied Polymer Materials), T. Randall Lee(Deputy Editor, ACS Applied Nano Materials), Jodie L. Lutkenhaus(Deputy Editor, ACS Applied Polymer Materials), David Kaplan(Editor-in-Chief, ACS Biomaterials Science & Engineering), Christopher Jones(Editor-in-Chief, ACS Catalysis), Carolyn Bertozzi(Editor-in-Chief, ACS Central Science), Laura Kiessling(Editor-in-Chief, ACS Chemical Biology), Mary Beth Mulcahy(Editor-in-Chief, ACS Chemical Health & Safety), Craig W. Lindsley(Editor-in-Chief, ACS Chemical Neuroscience), M. G. Finn(Editor-in-Chief, ACS Combinatorial Science), Joel D. Blum(Editor-in-Chief, ACS Earth and Space Chemistry), Prashant Kamat(Editor-in-Chief, ACS Energy Letters), Courtney C. Aldrich(Editor-in-Chief, ACS Infectious Diseases), Stuart Rowan(Editor-in-Chief, ACS Macro Letters), Bin Liu(Deputy Editor, ACS Materials Letters), Dennis Liotta(Editor-in-Chief, ACS Medicinal Chemistry Letters), Paul S. Weiss(Editor-in-Chief, ACS Nano), Deqing Zhang(Co-Editor, ACS Omega), Krishna N. Ganesh(Co-Editor, ACS Omega), Patrick Sexton(Editor-in-Chief, ACS Pharmacology & Translational Science), Harry A. Atwater(Editor-in-Chief, ACS Photonics), J. Justin Gooding(Editor-in-Chief, ACS Sensors), David T. Allen(Editor-in-Chief, ACS Sustainable Chemistry & Engineering), Christopher A. Voigt(Editor-in-Chief, ACS Synthetic Biology), Jonathan Sweedler(Editor-in-Chief, Analytical Chemistry), Alanna Schepartz(Editor-in-Chief, Biochemistry), Vincent Rotello(Editor-in-Chief, Bioconjugate Chemistry), Se´bastien Lecommandoux(Editor-in-Chief, Biomacromolecules), Shana J. Sturla(Editor-in-Chief, Chemical Research in Toxicology), Sharon Hammes-Schiffer(Editor-in-Chief, Chemical Reviews), Jillian Buriak(Editor-in-Chief, Chemistry of Materials), Jonathan W. Steed(Editor-in-Chief, Crystal Growth & Design), Hongwei Wu(Editor-in-Chief, Energy & Fuels), Julie Zimmerman(Editor-in-Chief, Environmental Science & Technology), Bryan Brooks(Editor-in-Chief, Environmental Science & Technology Letters), Phillip Savage(Editor-in-Chief, Industrial & Engineering Chemistry Research), William Tolman(Editor-in-Chief, Inorganic Chemistry), Thomas F. Hofmann(Editor-in-Chief, Journal of Agriculture and Food Chemistry), Joan F. Brennecke(Editor-in-Chief, Journal of Chemical & Engineering Data), Thomas A. Holme(Editor-in-Chief, Journal of Chemical Education), Kenneth M. Merz, Jr.(Editor-in-Chief, Journal of Chemical Information and Modeling), Gustavo Scuseria(Editor-in-Chief, Journal of Chemical Theory and Computation), William Jorgensen(Editor-in-Chief, Journal of Chemical Theory and Computation), Gunda I. Georg(Editor-in-Chief, Journal of Medicinal Chemistry), Shaomeng Wang(Editor-in-Chief, Journal of Medicinal Chemistry), Philip Proteau(Editor-in-Chief, Journal of Natural Products), John R. Yates, III(Editor-in-Chief, Journal of Proteome Research), Peter Stang(Editor-in-Chief, Journal of the American Chemical Society), Gilbert C. Walker(Editor-in-Chief, Langmuir), Marc Hillmyer(Editor-in-Chief, Macromolecules), Lynne S. Taylor(Editor-in-Chief, Molecular Pharmaceutics), Teri W. Odom(Editor-in-Chief, Nano Letters), Erick Carreira(Editor-in-Chief, Organic Letters), Kai Rossen(Editor-in-Chief, Organic Process Research & Development), Paul Chirik(Editor-in-Chief, Organometallics), Scott J. Miller(Editor-in-Chief, Journal of Organic Chemistry), Anne McCoy(Deputy Editor, Journal of Physical Chemistry A), Joan-Emma Shea(Editor-in-Chief, Journal of Physical Chemistry A/B/C), Martin Zanni(Deputy Editor, Journal of Physical Chemistry B), Catherine Mur

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Catalyst- and Solvent-Free Hydrophosphorylation of Ketones with Secondary Phosphine Oxides: Green Synthesis of Tertiary α-Hydroxyphosphine Oxides

doi.org/10.1055/s-0040-1707945

Synthesis
DOI: 10.1055/s-0040-1707945

Tertiary α-hydroxyphosphine oxides have been synthesized via the catalyst- and solvent-free reaction between available secondary phosphine oxides and aliphatic, aromatic and heteroaromatic ketones at 20–62 °C in near to 96–98% yield. The developed method meets the requirements of green chemistry and the PASE (pot, atom, step economy) paradigm. According to quantum-chemical calculations at the B3LYP/6-311++G(d,p) level, the synthesized hydroxyphosphine oxides feature a weak (≈3 kcal·mol–1) O−H···O=P intramolecular hydrogen bond.
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© Georg Thieme Verlag Stuttgart · New York

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Authors: Gusarova, Nina K.

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BF3·OEt2-Catalyzed Aldol Condensation of Steroid Sapogenins and 2-Oxoacids: A Single Step Conversion of Steroid Spiroketals into Branched α,β-Unsaturated Spirolactones

doi.org/10.1055/s-0040-1708018

Synthesis
DOI: 10.1055/s-0040-1708018

BF3·OEt2-catalyzed aldol reaction of steroid sapogenins with glyoxylic acid or pyruvic acid led to compounds in which the novel spirocyclic side chain bears an α,β-unsaturated lactone. The structures of the new spirolactones were established with the aid of combined 1D and 2D NMR techniques. A plausible mechanism is described.
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© Georg Thieme Verlag Stuttgart · New York

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Authors: Hernández-Martínez, Juan E.

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Enhanced reactivity of twisted amides inside a molecular cage

Nature Chemistry, Published online: 20 April 2020; doi:10.1038/s41557-020-0455-yThe distortion of an amide group away from a planar conformation typically enhances its reactivity and such activation is usually achieved through the chemical synthesis of twisted amides. Now, it has been shown that a non-covalent activation strategy leading to accelerated hydrolysis can be achieved by binding a reactive twisted amide conformer inside a molecular cage.Authors: Hiroki

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Enantioselective photoinduced cyclodimerization of a prochiral anthracene derivative adsorbed on helical metal nanostructures

Nature Chemistry, Published online: 20 April 2020; doi:10.1038/s41557-020-0453-0The photoinduced dimerization of a prochiral anthracenecarboxylic acid occurs in an enantioselective fashion when the molecules are adsorbed on helical metal nanostructures. This enantiopreference arises mostly from the helicity of the silver and copper substrates—prepared using shear forces during the deposition process—and may also be influenced by chiroplasmonic effects.Authors: Xueqin

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A silicon–carbonyl complex stable at room temperature

Nature Chemistry, Published online: 20 April 2020; doi:10.1038/s41557-020-0456-xCompounds of main-group elements rarely undergo direct carbonylation reactions. Now, an electron-rich silylene intermediate has been shown to readily react with CO to form a silylene carbonyl complex that is stable at room temperature. This complex engages in CO substitution as well as oxidative addition reactions.Authors: Chelladurai

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Reductive Amination of Aryl Boronic Acids: Parallelism of the Catalytic Reactivity of Transition Metals and Main Group Elements in the C(sp2)–N Bond-Forming Reactions

doi.org/10.1055/s-0039-1690893

Synthesis
DOI: 10.1055/s-0039-1690893

The results of the DFT studies on the mechanism of the PIII/PV=O catalyzed reductive amination of nitrosoarenes using ArB(OH)2 yielding diaryl amines are reported. This allowed a comparison of the reaction paths and key intermediates of the Cu(I)- and P(III)-mediated reductive aminations of aryl boronic acids using alkylnitrites, nitroso- or nitroarenes, and revealed important similarities in the catalytic reactivity of transition-metal and main-group elements in C(sp2)–N bond-forming reactions. It is shown that both transformations occur via ambiphilic nitrenoid-type key intermediates, the reactivity of which towards the aryl boronic acid is attributed to the presence of both a Lewis acid center (Cu or P) and a Lewis base center (the N or O atoms of the ‘N=O’ component).
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© Georg Thieme Verlag Stuttgart · New York

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Authors: Levitskiy, Oleg A.

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Zeolites Catalyze the Nazarov Reaction and the tert-Butylation of Alcohols by Stabilization of Carboxonium Intermediates

doi.org/10.1055/s-0039-1690896

Synthesis
DOI: 10.1055/s-0039-1690896

Zeolites are the most used catalysts worldwide in petrochemistry processes, with particular ability to stabilize carbocations. However, the use of zeolites in organic synthesis is still scarce. We show here that representative carboxonium-mediated organic reactions, such as the Nazarov cyclization and the tert-butylation of alcohols with tert-butyl acetate, typically performed with very strong acid catalysts in solution such as triflic acid, can be catalyzed by simple zeolites with high yield and selectivity. The aluminosilicate framework stabilizes the intermediate carboxonium species and overrides the need for superacid protons in solution.
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© Georg Thieme Verlag Stuttgart · New York

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Authors: Tejeda-Serrano, María

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Further Development of the Tin-Catalyzed Transcarbamoylation Reaction

doi.org/10.1055/s-0040-1708020

Synthesis
DOI: 10.1055/s-0040-1708020

Studies carried out to further develop tin-catalyzed trans­carbamoylation reactions demonstrated that transcarbamoylation of cinnamyl alcohol in the context of allyl cyanate-to-isocyanate rearrangement can be efficiently carried out on a ten-gram scale and that tin-­catalyzed transcarbamoylation is a valuable alternative to the method using trichloroacetyl isocyanate. In addition, methyl carbamate was found to be an economical carabamoyl donor in tin-catalyzed transcarbamoylation, which showed broad functional group tolerance and allowed a streamlined workup procedure. Finally, a unique synthetic method was developed for the preparation of carbamate-tethered terpene glycoconjugates.
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© Georg Thieme Verlag Stuttgart · New York

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Authors: Ichikawa, Yoshiyasu

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An Unusual Triazole Synthesis from Aurones

doi.org/10.1055/s-0040-1708019

Synthesis
DOI: 10.1055/s-0040-1708019

Attempts to prepare azido-substituted aurones via a copper-catalyzed azidation failed to afford the desired product, but instead resulted in an unusual triazole formation reaction. Further efforts noted that copper was not required for this reaction, but simply thermal treatment with sodium azide in a polar aprotic solvent. A wide range of substitution patterns were tolerated in this reaction to afford the interesting salicyl-substituted triazoles in modest to excellent yield. While the mechanism is not yet clear, a simple elimination/cyclization pathway seems unlikely given the failure of the reaction on the corresponding thioaurones, which feature an even better thiol leaving group. Regardless, the potential utility of these easily accessible, multifunctional compounds should engender further interest and applications.
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© Georg Thieme Verlag Stuttgart · New York

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Authors: Kafle, Arjun

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Manifestation of the β-Silicon Effect in the Reactions of Unsaturated Systems Involving a 1,2-Silyl Shift

doi.org/10.1055/s-0039-1690898

Synthesis
DOI: 10.1055/s-0039-1690898

Many chemical transformations of organosilicon compounds proceed due to the capability of silyl substituents to stabilize a positive charge in its β-position. This short review provides an overview of the present understanding of the β-silicon effect and focusses on the synthetic applications of 1,2-silyl shifts resulting from non-vertical stabilization of alkylcarbenium ions and vinyl cations. The reactions of silicon containing unsaturated starting materials, alkenes, allenes, and alkynes, involving β-silyl group stabilized cationic intermediates, transition metal carbenes, or vinylidene complexes will be discussed.1 Introduction2 Origins of the β-Silicon Effect3 Reactions of Allenylsilanes4 Reactions of Alkynes4.1 Propargylsilanes4.2 Alkynylsilanes5 Reactions of Alkenes5.1 Allylsilanes5.2 Vinylsilanes6 Conclusions
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© Georg Thieme Verlag Stuttgart · New York

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Authors: Beļaunieks, Rūdolfs

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