The “η-sweet-spot” (ηmax) in liquid-assisted mechanochemistry: polymorph control and the role of a liquid additive as either a catalyst or an inhibitor in resonant acoustic mixing (RAM) DOI
Lori Gonnet,

Tristan H. Borchers,

Cameron B. Lennox

et al.

Faraday Discussions, Journal Year: 2022, Volume and Issue: 241, P. 128 - 149

Published: Aug. 8, 2022

Resonant acoustic mixing (RAM) offers a simple, efficient route for mechanochemical synthesis in the absence of milling media or bulk solvents. Here, we show use RAM to conduct copper-catalysed coupling sulfonamides and carbodiimides. This was previously reported take place only by ball milling, while conventional solution environments it is not efficient, does at all. The results demonstrate as suitable methodology reactions accessed provide detailed, systematic overview how amount liquid additive, measured ratio volume weight reactants (η, μL mg-1), can affect course reaction polymorphic composition its product. Switching from allowed discovery new polymorph model sulfonylguanidine obtained catalytic di(cyclohexyl)carbodiimide (DCC) p-toluenesulfonamide, ability control temperature enabled situ behaviour this nascent We that conversion given time change monotonically but, instead, achieves maximum well-defined η-value. "η-sweet-spot" herein designated ηmax. explored sensitivity η on order 0.01 mg-1, which corresponds an additive below 5 mol% compared reactants, least one two orders magnitude lower than η-value typically considered design liquid-assisted reactions. Such suggests strategies optimise should systematically evaluate η-values increments even finer. At other ηmax drops off, demonstrating same act either catalyst inhibitor reaction, depending amount.

Language: Английский

The Direct Mechanocatalytic Suzuki–Miyaura Reaction of Small Organic Molecules DOI
Wilm Pickhardt,

Claudio Beaković,

Maike Mayer

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(34)

Published: May 31, 2022

Abstract The molecular Suzuki cross‐coupling reaction was conducted mechanochemically, without solvents, ligands, or catalyst powders. Utilizing one catalytically active palladium milling ball, products could be formed in quantitative yield as little 30 min. In contrast to previous reports, the adjustment of parameters led complete elimination abrasion from thus enabling first reported systematic analysis. XPS, situ XRD, and reference experiments provided evidence that ball surface location catalysis, allowing a mechanism proposed. versatility approach demonstrated by extending substrate scope deactivated even sterically hindered aryl iodides bromides.

Language: Английский

Citations

39
Direct mechanocatalysis by resonant acoustic mixing (RAM) DOI Creative Commons
Cameron B. Lennox,

Tristan H. Borchers,

Lori Gonnet

et al.

Chemical Science, Journal Year: 2023, Volume and Issue: 14(27), P. 7475 - 7481

Published: Jan. 1, 2023

We demonstrate the use of a metal surface to directly catalyse copper-catalysed alkyne-azide click-coupling (CuAAC) reactions under conditions Resonant Acoustic Mixing (RAM) - recently introduced and scalable mechanochemical methodology that uniquely eliminates need for bulk solvent, as well milling media. By using simple copper coil catalyst, this work shows direct mechanocatalysis can occur in an impact-free environment, relying solely on high-speed mixing reagents against surface, without specially designed containers introducing experimental setup enables real-time Raman spectroscopy monitoring RAM processes, we 0th-order reaction kinetics several selected CuAAC reactions, supporting surface-based catalysis. The herein presented RAM-based is simple, effective one-pot, two-step synthesis triazoles

Language: Английский

Citations

33
The Sonogashira Coupling on Palladium Milling Balls—A new Reaction Pathway in Mechanochemistry DOI Creative Commons
Wilm Pickhardt,

Eleonora Siegfried,

Sven Fabig

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(27)

Published: April 5, 2023

Abstract Utilizing direct mechanocatalytical conditions, the Sonogashira coupling was successfully performed on surface of milling tools by using pure Pd and coated steel balls. The optimization co‐catalyst forming additives led to a protocol, which generates quantitative yields under aerobic conditions for various substrates within as little 90 minutes. Using state‐of‐the‐art spectroscopic, diffractive, well in situ methods lead identification previously unknown highly reactive complex copper. This new differs substantially from known complexes liquid phase couplings, proving that reaction pathways mechanochemistry may differ those established synthetic procedures.

Language: Английский

Citations

27
Mechanochemical Synthesis of Aryl Fluorides by Using Ball Milling and a Piezoelectric Material as the Redox Catalyst DOI
Xiaohong Wang, Xuemei Zhang, Xue Li

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(39)

Published: July 31, 2023

Abstract Aryl fluorides are important structural motifs in many pharmaceuticals. Although the Balz–Schiemann reaction provides an entry to aryl from aryldiazonium tetrafluoroborates, it suffers drawbacks such as long time, high temperature, toxic solvent, gas release, and low functional group tolerance. Here, we describe a general method for synthesis of tetrafluoroborates using piezoelectric material redox catalyst under ball milling conditions presence Selectfluor. This approach effectively addresses aforementioned limitations. Furthermore, can be recycled multiple times. Mechanistic investigations indicate that this fluorination may proceed via radical pathway, Selectfluor plays dual role both source fluorine terminal reductant.

Language: Английский

Citations

27
Lithium-Mediated Mechanochemical Cyclodehydrogenation DOI

Kanna Fujishiro,

Yuta Morinaka,

Yohei Ono

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(14), P. 8163 - 8175

Published: April 3, 2023

Cyclodehydrogenation is an essential synthetic method for the preparation of polycyclic aromatic hydrocarbons, heteroaromatic compounds, and nanographenes. Among many examples, anionic cyclodehydrogenation using potassium(0) has attracted chemists because its irreplaceable reactivity utility in obtaining rylene structures from binaphthyl derivatives. However, existing methods are difficult to use terms practicality, pyrophoricity, lack scalability applicability. Herein, we report development a lithium(0)-mediated mechanochemical reaction first time. This could be easily performed conventional easy-to-handle lithium(0) wire at room temperature, even under air, 1,1′-binaphthyl complete within 30 min afford perylene 94% yield. Using this novel user-friendly protocol, investigated substrate scope, mechanism, gram-scale synthesis. As result, remarkable applicability practicality over previous methods, as well limitations, were comprehensively studied by computational studies nuclear magnetic resonance analysis. Furthermore, demonstrated two-, three-, five-fold cyclodehydrogenations synthesis In particular, quinterrylene ([5]rylene or pentarylene), longest nonsubstituted molecular rylene, was synthesized

Language: Английский

Citations

25
Synthesis without solvent: consequences for mechanochemical reactivity DOI Creative Commons
Lauren E. Wenger, Timothy P. Hanusa

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(96), P. 14210 - 14222

Published: Jan. 1, 2023

Solution-based reactions are a staple of synthetic chemistry—but what happens mechanochemically, when there is no solvent?

Language: Английский

Citations

21
Milling Medium‐Free Suzuki Coupling by Direct Mechanocatalysis: From Mixer Mills to Resonant Acoustic Mixers** DOI Creative Commons
Maximilian Wohlgemuth,

Sarah Schmidt,

Maike Mayer

et al.

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(65)

Published: July 28, 2023

Here we describe the development of a sustainable and cost-effective approach for catalytic cross-coupling reactions in mechanochemistry. It is found that substrate's impact with vessel wall alone sufficient to initiate reaction, thus indicating milling balls function primarily as mixing agent direct mechanocatalytic Suzuki coupling. The absence can be offset by adjusting rheology using liquid-assisted grinding (LAG). LAG sweet spot 0.25 μL mg-1 confirmed both resonance acoustic mixers (RAMs) ball-free mixer mills, higher than presence balls. RAMs exhibit excellent performance achieving yields 90 % after 60 min complete conversion min. longevity significantly improved RAM, allowing at least 20 without deterioration.

Language: Английский

Citations

19
Mechanochemical Birch Reduction with Low Reactive Alkaline Earth Metals DOI
Jagadeesh Varma Nallaparaju,

Riin Satsi,

Danylo Merzhyievskyi

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(20)

Published: March 4, 2024

Abstract Birch reduction and similar dissolved metal‐type transformations hold significant importance in the organic synthesis toolbox. Historically, field has been dominated by alkali metal reductants. In this study, we report that largely neglected, low‐reactive alkaline earth metals can become powerful affordable reductants when used a ball mill under essentially solvent‐free conditions, presence of ethylenediamine THF as liquid additives. Calcium reduce both electron‐deficient electron‐rich arenes, with yields products to those obtained lithium metal. Magnesium reveals enhanced reducing power, enabling benzoic acids while keeping aromatic moieties intact allows for chemoselective transformations. The developed mechanochemical approach uses readily available safer‐to‐handle metals, operates air ambient temperature be gram‐scale preparations. Finally, demonstrate conditions other reductive transformations, including amination, deoxygenation, dehalogenation, alkene alkyne reductions.

Language: Английский

Citations

8
Mechanical‐Force‐Induced Non‐spontaneous Dehalogenative Deuteration of Aromatic Iodides Enabled by Using Piezoelectric Materials as a Redox Catalyst DOI

Ruiling Qu,

Shan Wan, Xuemei Zhang

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(28)

Published: April 30, 2024

Abstract The development of green and efficient deuteration methods is great significance for various fields such as organic synthesis, analytical chemistry, medicinal chemistry. Herein, we have developed a dehalogenative strategy using piezoelectric materials catalysts in solid‐phase system under ball‐milling conditions. This non‐spontaneous reaction induced by mechanical force. D 2 O can serve both deuterium source an electron donor the transformation, eliminating need additional stoichiometric exogenous reductants. A series (hetero)aryl iodides be transformed into deuterated products with high incorporation. method not only effectively overcomes existing synthetic challenges but also used labelling drug molecules derivatives. Bioactivity experiments molecule suggest that D‐ipriflavone enhances inhibitory effects on osteoclast differentiation BMDMs vitro .

Language: Английский

Citations

8
Mechanochemistry for Organic and Inorganic Synthesis DOI Creative Commons
Javier F. Reynes, Félix León, Felipe Garcı́a

et al.

ACS Organic & Inorganic Au, Journal Year: 2024, Volume and Issue: 4(5), P. 432 - 470

Published: Aug. 7, 2024

In recent years, mechanochemistry has become an innovative and sustainable alternative to traditional solvent-based synthesis. Mechanochemistry rapidly expanded across a wide range of chemistry fields, including diverse organic compounds active pharmaceutical ingredients, coordination compounds, organometallic complexes, main group frameworks, technologically relevant materials. This Review aims highlight advancements accomplishments in mechanochemistry, underscoring its potential as viable eco-friendly conventional solution-based methods the field synthetic chemistry.

Language: Английский

Citations

8