Mechanochemical N-alkylation of imides

• Anamarija Briš,
• Mateja Đud and
• Davor Margetić

Beilstein J. Org. Chem. 2017, 13, 1745–1752, doi:10.3762/bjoc.13.169

• . Reactions under solvent-free conditions in a ball mill gave good yields and could be put in place of the classical solution conditions. The method is general and can be applied to various imides and alkyl halides. Phthalimides prepared under ball milling conditions were used in a mechanochemical Gabriel

• employed. By conducting the reaction in a ball mill, solubility problems and the issues associated with the selection of the most suitable solvent could be avoided. In addition, solid-state reaction diminishes the heterogeneous character of alkylation, since inorganic bases in general are not soluble in

• ) Gabriel synthesis of amines was carried out in a ball mill. The synthetically desired development of a three-step, one-pot mechanochemical Gabriel synthesis of amines could not be accomplished, as the complex reaction mixtures containing considerable amounts of various side products such as bisamide 43

Encaging palladium(0) in layered double hydroxide: A sustainable catalyst for solvent-free and ligand-free Heck reaction in a ball mill

• Wei Shi,
• Jingbo Yu,
• Zhijiang Jiang,
• Qiaoling Shao and
• Weike Su

Beilstein J. Org. Chem. 2017, 13, 1661–1668, doi:10.3762/bjoc.13.160

• hybrid LDHs were then reduced by hydrazine hydrate (N2H4·H2O) to obtain the Pd catalyst supported on MgAl-LDHs (Pd/MgAl-LDHs). The as-prepared Pd/MgAl-LDH catalyst was further applied in representative cross-coupling Heck reactions under HSBM conditions (Scheme 1) by using a planetary ball mill

Mechanochemical borylation of aryldiazonium salts; merging light and ball milling

• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1463–1469, doi:10.3762/bjoc.13.144

• Jose G. Hernandez Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, D-52074 Aachen, Germany 10.3762/bjoc.13.144 Abstract Merging of photo- and mechanochemical activation permitted studying the role of eosin Y in the borylation of aryldiazonium salts in a ball mill

• ball mill (Table 2). Control experiments by stirring/heating 1a–d and 2 in an oil bath until the melting of the mixture was reached, showed predominantly thermal decomposition of the aryldiazonium salts 1a–d into the 1-halo-4-fluorobenzene derivatives [23] and only in some cases trace quantities of 3a

• light on the role of the photocatalyst in the borylation of the aryldiazonium salts. Under non-catalyzed LAG/irradiation conditions, charge-transfer complexes between 1a and appropriate organic solvents could be responsible for the fast generation of the aryl cations in the ball mill, leading to the

Mechanochemical synthesis of graphene oxide-supported transition metal catalysts for the oxidation of isoeugenol to vanillin

• Ana Franco,
• Sudipta De,
• Alina M. Balu,
• Araceli Garcia and
• Rafael Luque

Beilstein J. Org. Chem. 2017, 13, 1439–1445, doi:10.3762/bjoc.13.141

• materials, reduced graphene oxide (RGO) support, together with an appropriate amount of the iron precursor (FeCl2∙4H2O) to reach a theoretical 1% iron loading, was ground by using a Retsch-PM-100 planetary ball mill with a 25 mL reaction chamber and 8 mm stainless steel ball. Milling was conducted at 350

Mechanochemistry-assisted synthesis of hierarchical porous carbons applied as supercapacitors

• Desirée Leistenschneider,
• Nicolas Jäckel,
• Felix Hippauf,
• Volker Presser and
• Lars Borchardt

Beilstein J. Org. Chem. 2017, 13, 1332–1341, doi:10.3762/bjoc.13.130

• Engineering, Saarland University, Saarbrücken, Germany Fraunhofer Institute for Material and Beam Technology IWS, Dresden, Germany 10.3762/bjoc.13.130 Abstract A solvent-free synthesis of hierarchical porous carbons is conducted by a facile and fast mechanochemical reaction in a ball mill. By means of a

• ball mill, and thus simplify the synthesis of hierarchical porous carbons drastically. Moreover, it is the first proof that even well-defined carbon pore structures can be derived making use of solid-state conditions like ball-milling. In detail, we apply the Pechini method, an approach commonly used

Kinetic analysis of mechanoradical formation during the mechanolysis of dextran and glycogen

• Naoki Doi,
• Yasushi Sasai,
• Yukinori Yamauchi,
• Tetsuo Adachi,
• Masayuki Kuzuya and
• Shin-ichi Kondo

Beilstein J. Org. Chem. 2017, 13, 1174–1183, doi:10.3762/bjoc.13.116

• homogeneous scission (mechanoradical formation) but also heterogeneous bond cleavage (mechanoanion formation) took place in the course of mechanochemical reaction of bacterial cellulose in a glass ball mill in vacuum in the dark at 77 K [23]. The same authors also demonstrated the modification of

Nucleophilic displacement reactions of 5′-derivatised nucleosides in a vibration ball mill

• Olga Eguaogie,
• Patrick F. Conlon,
• Francesco Ravalico,
• Jamie S. T. Sweet,
• Thomas B. Elder,
• Louis P. Conway,
• Marc E. Lennon,
• David R. W. Hodgson and
• Joseph S. Vyle

Beilstein J. Org. Chem. 2017, 13, 87–92, doi:10.3762/bjoc.13.11

• corresponding 5′-selenocyanates in variable yields over the course of between one and eleven hours thereby avoiding the preparation and use of hygroscopic tetrabutylammonium salts. Keywords: ball mill; chalcogen; mechanochemistry; nucleophilic substitution; nucleoside; Introduction Nucleophilic displacement

• liquid [13][14][15]. Recently, Jicsinszky et al. described using a planetary ball mill to perform substitution reactions of 6I-O-(p-toluenesulfonyl)-β-cyclodextrin (Ts-β-CD) with azide, halide or thiolate nucleophiles and thereby avoided intramolecular cyclisation (commonly found under solution-phase

• conditions) [16]. Following Sikchi and Hultin’s original description of nucleoside derivatisation in a low-energy, planetary ball mill [17], commercial, higher energy vibration mills have been used to facilitate established [18][19][20][21] and unprecedented [22] nucleoside transformations. Remarkably, SN2

Extrusion – back to the future: Using an established technique to reform automated chemical synthesis

• Deborah E. Crawford

Beilstein J. Org. Chem. 2017, 13, 65–75, doi:10.3762/bjoc.13.9

• technique in chemical synthesis, for example, reactions between two or more liquids have not been studied by extrusion and may be more difficult to carry out. In fact, there are still very few examples of this reported in ball mill reactions. Secondly, although it has been described that pyrophoric

• successful by ball milling also. Condensation reactions (e.g., Knoevenagel condensations, Michael additions and Aldol reactions) in particular are the most obvious reaction to be successful by extrusion due to its general success in the ball mill, and as their reactions can be accelerated by the simple

Poly(ethylene glycol)s as grinding additives in the mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins

• Andrea Mascitti,
• Massimiliano Lupacchini,
• Ruben Guerra,
• Ilya Taydakov,
• Lucia Tonucci,
• Nicola d’Alessandro,
• Frederic Lamaty,
• Jean Martinez and
• Evelina Colacino

Beilstein J. Org. Chem. 2017, 13, 19–25, doi:10.3762/bjoc.13.3

• other alternative energy inputs is still scarce. Only three examples highlight their peculiar role for metal-catalysed processes in a ball mill (Mirozoki–Heck reaction) [6], by ultrasound (copper-catalysed cyanation reaction) [7], and for co-crystal formation in the polymer-assisted grinding process

Efficient mechanochemical synthesis of regioselective persubstituted cyclodextrins

• Laszlo Jicsinszky,
• Marina Caporaso,
• Katia Martina,
• Emanuela Calcio Gaudino and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2016, 12, 2364–2371, doi:10.3762/bjoc.12.230

• -6-substituted cyclodextrin derivative syntheses have been effectively carried out in a planetary ball mill under solvent-free conditions. The preparation of Bridion® and important per-6-amino/thiocyclodextrin intermediates without polar aprotic solvents, a source of byproducts and persistent

• millimolar scale, they are easily scalable. Keywords: green chemistry; nucleophilic substitution; planetary ball mill; siRNA delivery intermediate; sugammadex; Introduction Cyclodextrins (CDs) are cyclic α(1→4)glucopyranosides and have been fully described in a number of publications [1][2][3]. They are

• friendly procedures. Ball mill assisted syntheses are good alternatives to overcome solubility difficulties in syntheses or isolation of natural compounds from vegetables using CDs [9][10]. Environmentally benign synthetic methods of CD derivatives have been recently reviewed [11]. The key intermediate in

Solvent-free, visible-light photocatalytic alcohol oxidations applying an organic photocatalyst

• Martin Obst and
• Burkhard König

Beilstein J. Org. Chem. 2016, 12, 2358–2363, doi:10.3762/bjoc.12.229

• for the investigation of our solvent-free principle. In mechanochemistry, reactions are performed by grinding the reaction mixture in ball mills, such as the vibrational ball mill or the planetary ball mill, or with a pestle and mortar. In preliminary studies, we tested a vibrational ball mill for

Supported bifunctional thioureas as recoverable and reusable catalysts for enantioselective nitro-Michael reactions

• José M. Andrés,
• Miriam Ceballos,
• Alicia Maestro,
• Isabel Sanz and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2016, 12, 628–635, doi:10.3762/bjoc.12.61

• (1a) under solvent-free conditions in a ball mill providing the addition product 7aa in excellent yield, total diastereoselectivity, and very good enantioselectitvity. Experimental General remarks 13C NMR (126 MHz) and 1H NMR (500 MHz) spectra were recorded in CDCl3 as the solvent. Chemical shifts for

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• diphenylcarbonate in DMF, have been prepared under MW irradiation (400 W) in 90 min. The optimized method was proven to be a unique opportunity for the large-scale synthesis of CD nanosponges in a high yield and uniform particle size distribution [78]. Ball mill One of the oldest, cheap, and efficient methods to

Mechanochemistry assisted asymmetric organocatalysis: A sustainable approach

• Pankaj Chauhan and
• Swapandeep Singh Chimni

Beilstein J. Org. Chem. 2012, 8, 2132–2141, doi:10.3762/bjoc.8.240

• solvent-free conditions by using a planetary ball mill (Scheme 7) [46]. Cinchona-derived chiral squaramide IX, at low catalyst loading of 0.5 mol %, efficiently catalyses the solvent-free Michael reaction of acetylacetone (9) with various substituted nitroalkenes 7 in a short reaction time (5–30 minutes

• by milling protected glycine hydrochloride 21 and diphenylmethanimine (20), under solvent-free conditions (Scheme 11) [62]. The asymmetric alkylation of glycine imine 22 was carried out by using a phase-transfer catalyst under basic conditions in a ball-mill. The Schiff base reacted rapidly with

• various halogenated derivatives 23 in a ball-mill in the presence of KOH and the chiral ammonium salt derived from cinchonidine (XIII) as phase-transfer catalyst, to provide excellent yield (91–97%) and good enantioselectivity (35–75% ee) of the corresponding amino esters 24. Purification of the product

Solvent-free and time-efficient Suzuki–Miyaura reaction in a ball mill: the solid reagent system KF–Al₂O₃ under inspection

• Franziska Bernhardt,
• Ronald Trotzki,
• Tony Szuppa,
• Achim Stolle and
• Bernd Ondruschka

Beilstein J. Org. Chem. 2010, 6, No. 7, doi:10.3762/bjoc.6.7

• mechanical manner by co-grinding the reactants with agate milling balls using a planetary ball mill as the source for alternative energy input [4][5][6][9][36][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56]. It is worth mentioning that all results presented in this paper were achieved by

• acid and surface oxygen of alumina (ArB(OH)2–O–Al(O–)3). The reported results also confute the results from microwave-assisted cross-coupling with pure basic alumina, which was seen to be completely inert for this type of reaction [33]. Apparently co-grinding of all reactants in a ball mill leads to in

• without further purification. SRS4a and SRS5a were purchased from Sigma-Aldrich (cf. Supporting Information File 1) and used without further pre-treatment. Ball milling was conducted using the planetary ball mill “Pulverisette 7 classic line” (Fritsch GmbH, Germany). For balancing, two grinding beakers (V