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Search for "ball mill" in Full Text gives 65 result(s) in Beilstein Journal of Organic Chemistry.
Mechanochemical Friedel–Crafts acylations
Beilstein J. Org. Chem. 2019, 15, 1313–1320, doi:10.3762/bjoc.15.130
- method in the synthesis of covalent triazine frameworks. Herein, we report related results on solvent-free FC acylation reactions conducted in a ball mill, which is the continuation of our program in organic mechanosynthesis [20][21][22][23][24]. Results and Discussion Mechanochemical FCR of pyrene (1
- 15). The results on optimization of reaction conditions in the ball mill indicate that FC acylation could be effectively carried out mechanochemically. The best mechanochemical reaction conditions (Table 1, entry 4): 2 h, equimolar amount of phthalic anhydride and 2.5 equivalents of AlCl3, afforded
- species (time needed to transfer sample from ball mill to IR spectrophotometer and acquire spectra are within several minutes, which could be detrimental to reactive species to survive in the open air). These signals are not visible after the standard acidic work-up and further study would require the use
Understanding the unexpected effect of frequency on the kinetics of a covalent reaction under ball-milling conditions
Beilstein J. Org. Chem. 2019, 15, 1226–1235, doi:10.3762/bjoc.15.120
- Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK 10.3762/bjoc.15.120 Abstract We here explore how ball-mill-grinding frequency affects the kinetics of a disulfide exchange reaction. Our kinetic data show that the reaction progress is similar at all the frequencies studied (15–30 Hz
- local defects accumulate preferentially at or near the crystal surface. Since the total area increases exponentially when the crystal size is reduced by the crystal-breaking process, this can further explain the exponential dependence of the onset time on the milling frequency. Keywords: ball-mill
- grinding; grinding frequency; kinetics; mechanism; mechanochemistry; Introduction We describe here an unusual frequency-dependence in the induction period of a covalent reaction carried out using ball-mill grinding. We present a kinetic analysis indicating that this is due to the successive fracture of
Mechanochemical synthesis of hyper-crosslinked polymers: influences on their pore structure and adsorption behaviour for organic vapors
Beilstein J. Org. Chem. 2019, 15, 1154–1161, doi:10.3762/bjoc.15.112
- parameter was determined to be the rotational speed of the ball mill. At 200 rpm this led to a low SSA (7–66 m2g−1) due to an incomplete polymerization, while 800 rpm resulted in a medium SSA (600–820 m2g−1). This observation is hinting towards a partial degradation of the porosity by the high energy input
- and the resulting thermal and frictional stress of the material and reinforces our prior findings regarding the synthesis of porous polymers inside a ball mill [30][35]. Development of vessel pressure during the reaction In an attempt to track and understand the kinetics of the mechanochemical
- physisorption experiments, all samples were activated at 353 K for 24 h under vacuum. Ball mill syntheses were carried out in a Fritsch Pulverisette 7 premium line planetary ball mill. Infrared spectroscopy (IR) was carried out on a Bruker Vertex 70 with a Specac Golden Gate ATR unit. A resolution of 2 cm−1 was
Unexpected polymorphism during a catalyzed mechanochemical Knoevenagel condensation
Beilstein J. Org. Chem. 2019, 15, 1141–1148, doi:10.3762/bjoc.15.110
- in our previous work [29]. Milling experiments were performed using a commercially available vibratory ball mill (Pulverisette 23, Fritsch, Germany). For each experiment, stoichiometric quantities of reactants p-, m- and o- fluorobenzaldehyde (500 mg, ca. 4.03 mmol) and malonodinitrile (266.1 mg, ca
Mechanochemical synthesis of poly(trimethylene carbonate)s: an example of rate acceleration
Beilstein J. Org. Chem. 2019, 15, 963–970, doi:10.3762/bjoc.15.93
- showed that poly(ethylene oxide) end group modification is facile under ball-mill conditions [16]. Network polymeric material fabrications were also realized using ball milling [17][18][19]. As mentioned, many mechanochemical reactions realized exceptional efficiencies that solution synthesis cannot
- added. All reagents were placed in a 10 mL stainless-steel milling jar with three 7 mm diameter stainless-steel balls. The solid-state reaction mixture was placed into a high-speed vibration ball mill. After 30 min of high-speed vibration (30 Hz), 43% conversion was recorded, and PTMC with an Mn of 3930
- improvement of reaction efficiency. The high impact collision energy [28][29] and exothermic nature of the given ring-opening polymerization [30] could increase the temperature of a ball-mill system, which would speed up the polymerization rate [31][32]. To gain insight into thermal effects, we monitored the
Mechanochemistry of supramolecules
Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86
- stabilities by exhibiting a decomposition temperature up to 320 °C. In 2013, Severin and co-workers reported the mechanochemical synthesis of large macrocycles with borasiloxane and imine links using a ball mill (Figure 12). In a polycondensation reaction using diamines, 4-formylbenzeneboronic acid and t
- -benzenetricarbonyl chloride and 1,4-phenylenediamine in a ball mill afforded 75% of the desired 2D polymer 24 within 15 min (Figure 13). When using 4,4'-diaminobiphenyl in place of 1,4-phenylenediamine the analogous 2D structure comprising biphenylene units was obtained within the same time albeit with a lower yield
Synthesis of acylglycerol derivatives by mechanochemistry
Beilstein J. Org. Chem. 2019, 15, 811–817, doi:10.3762/bjoc.15.78
- , mechanosynthesis of lipids by ball milling techniques has remained essentially unexplored. In this work, a multistep synthetic route to access mono- and diacylglycerol derivatives by mechanochemistry has been realized, including the synthesis of diacylglycerol-coumarin conjugates. Keywords: ball mill; coumarin
- separation by column chromatography. A 5-fold scaled up version of the reaction using 3.37 mmol of 1 was carried out in a planetary ball mill (PBM) using 45 mL milling containers at 600 rpm, under otherwise identical conditions to afford product 2 in a similar yield. With TBDMS-protected glycidol 2 in our
- hands, a selective epoxide ring-opening reaction with fatty acids 3 leading to the formation of the corresponding sn-1,3-protected monoacylglycerols (MAGs 4) was attempted (Scheme 3). Initially, commonly used solution-based protocols were tested in the ball mill [33]. For example, 2 was reacted with
Synthesis of mono-functionalized S-diazocines via intramolecular Baeyer–Mills reactions
Beilstein J. Org. Chem. 2018, 14, 2799–2804, doi:10.3762/bjoc.14.257
- be reduced in a second synthetic step using lead in a ball mill. However, these reaction conditions are not suitable for functionalized S-diazocines due to poor yields and low reproducibility. Using halogenated precursors for the reductive azocoupling with lead a large amount of byproduct (details
- see Supporting Information File 1) is formed, which lowers the overall yield of S-diazocines 1–3 considerably. Further problems arise from the difficult separation of the azoxy compound from other byproducts. The yields of the azoxy reduction in the ball mill are varying between 18–46%. S-Diazocines
The mechanochemical synthesis of quinazolin-4(3H)-ones by controlling the reactivity of IBX
Beilstein J. Org. Chem. 2018, 14, 2396–2403, doi:10.3762/bjoc.14.216
- intramolecular control. At maximum contact of the reacting substances, i.e., under solvent-free mechanochemical conditions, 2-aminobenzamides, aryl-, alkylaldehydes and the iodine(V) reagent o-iodoxybenzoic acid (IBX) led to substituted quinazolin-4(3H)-one derivatives in fair yields. Keywords: ball-mill
Mechanochemistry of nucleosides, nucleotides and related materials
Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81
- substrates on preparative scales. A survey of these reactions is provided, the majority of which have used a mixer ball mill and display an almost universal requirement for liquid to be present within the grinding vessel. Mechanochemistry of charged nucleotide substrates, in particular, provides considerable
- ] augments an earlier introduction describing both the parameters used to define such chemistry and also how this information is conveyed in synthetic schemes [16]. Stolle has written a comprehensive treatise on the chemical, technological and process parameters which influence the outcome of a ball mill
- commercially-available equipment which, for reactions of nucleosides and related materials has most commonly been the mixer ball mill (MBM – e.g., Figure 1a). Using a MBM, high energy collisions between reactants and one or more balls within a closed vessel (jar) are induced by vibrating the jar through a
Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry
Beilstein J. Org. Chem. 2018, 14, 648–658, doi:10.3762/bjoc.14.52
- Resch PM10 planet ball mill equipped with metal balls (d = 8 mm, 500 rpm, 10 min milling time) was used for dry milling of powdered Ce0.495Sn0.495Pd0.01O2–δ and wet milling (suspension in water) of Ce0.20Sn0.79Pd0.01O2–δ, respectively. These two catalysts were chosen since they showed the highest
Palladium-catalyzed ortho-halogenations of acetanilides with N-halosuccinimides via direct sp2 C–H bond activation in ball mills
Beilstein J. Org. Chem. 2018, 14, 430–435, doi:10.3762/bjoc.14.31
- reaction time and provides a highly efficient methodology to realize the regioselective functionalization of acetanilides in yields up to 94% in a ball mill. Furthermore, the current methodology can be extended to the synthesis of ortho-brominated and ortho-chlorinated products in good yields by using the
- N-halosuccinimides. The influence of the milling frequency on the reaction of 1a with NIS. Palladium-catalyzed ortho-iodination of 1a in toluene. Plausible mechanism. Palladium-catalyzed ortho-bromination and chlorination of 1a in a ball mill. Optimization of the reaction conditions.a Substrate
Exploring mechanochemistry to turn organic bio-relevant molecules into metal-organic frameworks: a short review
Beilstein J. Org. Chem. 2017, 13, 2416–2427, doi:10.3762/bjoc.13.239
- rapidly inspired other groups to follow this methodology. This has been proved by the work of Wenbing Yuan et al., in which a very important 3D BioMOF, known as HKUST-1, was synthesized by grinding together copper acetate with 1,3,5-benzenetricarboxylic acid (BTC, Figure 3) in a ball mill for 15 minutes
Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole
Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232
- different copper species for the solvent-free mechanochemical CuAAC in a ball mill, we conducted a number of milling experiments where we assayed catalytic action of most commonly used copper(0), copper(I) and copper(II) catalysts. Mechanochemical reactions were compared to traditional solvent-based
A mechanochemical approach to access the proline–proline diketopiperazine framework
Beilstein J. Org. Chem. 2017, 13, 2169–2178, doi:10.3762/bjoc.13.217
- explained by DFT calculations. Using this method, an enantiopure disubstituted Pro–Pro diketopiperazine was synthesized in 4 steps, making 5 new bonds using a ball mill. Keywords: ball mill; DFT calculations; diketopiperazine; mechanochemistry; pyrrolidine; Introduction 2,5-Diketopiperazines (DKPs) are
- ][24][25][27] to prepare the Pro–Pro dipeptide from the corresponding amino acid derivatives. We investigated the coupling of proline N-hydroxysuccinimide ester with proline methyl ester in a vibrating ball mill (vbm, Scheme 2) [23]. Surprisingly, while the coupling of various other amino acids
- trans-11 (racemic), which could be separated by crystallization or column chromatography [17][32][33]. Trying to avoid as much as possible the use of (toxic) solvents, we considered extending the known nucleophilic substitution in a ball mill [34][35][36][37][38][39][40][41] to this reaction system
The effect of milling frequency on a mechanochemical organic reaction monitored by in situ Raman spectroscopy
Beilstein J. Org. Chem. 2017, 13, 2160–2168, doi:10.3762/bjoc.13.216
- milling frequency on the course of a mechanochemical organic reaction conducted using a vibratory shaker (mixer) ball mill. The use of in situ Raman spectroscopy for real-time monitoring of the mechanochemical synthesis of a 2,3-diphenylquinoxaline derivative revealed a pronounced dependence of chemical
- is one of the fundamental parameters of mechanochemical reactions conducted by ball milling, and for a vibratory shaker (mixer) ball mill it represents the number of full oscillations of the milling vessel (milling jar) per unit time along a curved path (Scheme 2). It is often used as a simple
Peptide synthesis: ball-milling, in solution, or on solid support, what is the best strategy?
Beilstein J. Org. Chem. 2017, 13, 2087–2093, doi:10.3762/bjoc.13.206
- build more efficient and sustainable peptide syntheses in the near future. Keywords: ball-mill; green chemistry; mechanochemistry; peptide synthesis; SPPS; Introduction Peptides play a central role both in biological mechanisms and in therapeutic solutions of the future [1][2]. Pharmaceutical
- impeller, and automated handling such as pumping and filtration. Since Lamaty and co-workers have shown in their seminal work that peptide synthesis could be performed in a ball-mill (BM) [9], various solvent-free or solvent-less peptide synthesis strategies have been developed [10][11][12][13][14][15][16
- peptide that inhibits Aβ42-induced neurotoxicity [21][22], and that is known to be difficult to produce due to high hydrophobicity and steric hindrance [23]. Results and Discussion Synthesis by using a ball-mill (BM) The Boc-VVIA-OBn tetrapeptide was first synthesized by using the ball-milling strategy
Mechanically induced oxidation of alcohols to aldehydes and ketones in ambient air: Revisiting TEMPO-assisted oxidations
Beilstein J. Org. Chem. 2017, 13, 2049–2055, doi:10.3762/bjoc.13.202
- commercial ball mill in the presence of stainless steel balls and air, and in the absence of solvent. The oxidation of solid 4-nitrobenzyl alcohol (1a) to 4-nitrobenzaldehyde (2a) was selected as a model reaction. Unfortunately, the alcohol-to-aldehyde conversion was very low (<15%), and the use of larger
Mechanochemical Knoevenagel condensation investigated in situ
Beilstein J. Org. Chem. 2017, 13, 2010–2014, doi:10.3762/bjoc.13.197
- interactions such as hydrogen bonds, halogen bonds, and π∙∙∙π interactions [16][17][18][19]. For example, Toda et al. reported yields of 97% for Aldol condensations in the absence of any solvents [20]. Kaupp et al. described the first Knoevenagel condensation in a ball mill [21]. Compared to conventional
- -nitrobenzaldehyde (1) with malononitrile (2) using a ball mill. The stoichiometric reaction mixture was ball-milled for 60 minutes at 50 Hz in a conventional ball mill with either stainless steel or Perspex grinding jars. For both jar materials, the X-ray diffraction patterns of the product in comparison to those
- ball milling is needed for the completion of the reaction. The ball mill was stopped after 36 minutes and the reaction in the closed jar was monitored with Raman spectroscopy. The data show that under these conditions the reaction to the final product is completed within two hours. Consequently
New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions
Beilstein J. Org. Chem. 2017, 13, 1982–1993, doi:10.3762/bjoc.13.194
- for the synthesis of the three catalysts Fe2O3-PS4, Fe2O3-PS4-MNP, and TiO2-Fe2O3-PS4. The three materials were synthesized using a 2:1 metal precursor/polysaccharide ratio (2 g of polysaccharide S4, 4 g of FeCl2·4H2O), in a ball mill (Retsch PM100 ball mill model), at 350 rpm for 30 min, using a 125
Mechanochemical synthesis of small organic molecules
Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186
- ]. In this section some of the most important C–C bond forming reactions and their advantages are discussed. Aldol reaction In 2000, Raston and Scott first reported the aldol condensation reaction using veratraldehyde, 4-phenylcyclohexanone and 1-indanone in the presence of NaOH in a vibrating ball mill
- reacting catalyst. Su and co-workers reported an Fe(III)-catalyzed coupling of 3-benzyl indoles with molecules having active methylene group under solvent-free ball-mill in presence of silica gel as milling auxiliary. Using 10 mol % Fe(NO3)3·9H2O as catalyst and 1.0 equiv of DDQ afforded good yield of
- 2016 Juaristi and co-workers have reported Ugi 4-component reactions (4-CR) by liquid-assisted grinding (LAG) using MeOH. Equimolar amounts of benzaldehyde, chloroacetic acid, tert-butyl isocyanide, and propargylamine in the presence of 2 mol % InCl3, under ball-mill yielded the desired Ugi product in
Influence of the milling parameters on the nucleophilic substitution reaction of activated β-cyclodextrins
Beilstein J. Org. Chem. 2017, 13, 1893–1899, doi:10.3762/bjoc.13.184
- effect on the nucleophilic reaction. Keywords: cyclodextrins; milling parameters; nucleophilic substitution; planetary ball mill; Introduction Their hollow structures make cyclodextrins (CDs) a class of carbohydrates that can form inclusion complexes with organic molecules, inorganic salts and complex
- derivatization [8]. Although the preparation of carbohydrate-based complexes in a ball mill has been already reported [9][10][11], the use of mechanical activation for the chemical derivatization of CDs has been rather sporadic [12][13][14][15]. In this respect, it is worth noting that CDs exhibit a
- . The reaction was performed in a planetary ball mill and the processing parameters were systematically varied with the aim of pointing out their influence on the nucleophilic substitution reactions in terms of rate and yield. Specifically systematic variation involved rotation speed, milling tool
Solvent-free sonochemistry: Sonochemical organic synthesis in the absence of a liquid medium
Beilstein J. Org. Chem. 2017, 13, 1850–1856, doi:10.3762/bjoc.13.179
- . Keywords: mechanochemistry; organic; solvent-free; sonochemistry; synthesis; Introduction Mechanochemistry is typically regarded as the grinding of solid reagents in a ball mill (or mortar and pestle), to instigate and accelerate chemical reactions [1]. In recent years, mechanochemistry has evolved to
- carried out (where grinding results in degradation of the material). Finally, as with ball milling, there is potential for the scale-up of sonochemical reactions, therefore aiding in the drive towards sustainable chemistry. Typical laboratory employed planetary ball mill and ultrasonic bath. o-Vanillin in
Mechanochemical synthesis of thioureas, ureas and guanidines
Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178
- milling was performed at low temperatures (−30 °C) using an in-house ball mill equipped with a cooling jacket. As isothiocyanate component, liquid phenyl isothiocyanate and solid methyl, 1-naphthyl, 4-bromophenyl and 4-nitrophenyl isothiocyanates were screened. While ammonia, methylamine and dimethylamine
- absorption bands of N-(4-bromophenyl)thiourea (32d) at 1617 and 509 cm−1. Several other thiocarbamoyl benzotriazoles were also quantitatively transformed to primary thioureas by this method. For the purpose of performing the amination reaction in a ball mill, ammonia gas was generated in situ by milling the
Selective enzymatic esterification of lignin model compounds in the ball mill
Beilstein J. Org. Chem. 2017, 13, 1788–1795, doi:10.3762/bjoc.13.173
- Ulla Weissbach Saumya Dabral Laure Konnert Carsten Bolm Jose G. Hernandez Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, D-52074 Aachen, Germany 10.3762/bjoc.13.173 Abstract A lipase-catalyzed esterification of lignin model compounds in the ball mill was developed combining
- out by ball milling, have recently attracted attention of a wider scientific community, owing to the many advantages the excellent mixing inside the ball mill can offer [1]. Besides avoiding or minimizing the use of organic solvents as reaction media, chemical transformations by ball milling very
- the ball mill (Scheme 1c). The results of this proof-of-concept study are presented here. Results and Discussion Due to the high complexity of the lignin structure, which often presents a challenge during the product composition analysis, the use of lignin model compounds to monitor preliminary
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