One-pot multistep mechanochemical synthesis of fluorinated pyrazolones

• Joseph L. Howard,
• William Nicholson,
• Yerbol Sagatov and
• Duncan L. Browne

Beilstein J. Org. Chem. 2017, 13, 1950–1956, doi:10.3762/bjoc.13.189

• Joseph L. Howard William Nicholson Yerbol Sagatov Duncan L. Browne School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, UK 10.3762/bjoc.13.189 Abstract Solventless mechanochemical synthesis represents a technique with improved sustainability metrics compared to

• small range of compounds. Conclusion In summary, we have developed a one-pot, two-step mechanochemical synthesis of fluorinated pyrazolones. The experiments provide a logical approach to multistep solventless synthesis under milling conditions and more broadly will assist in the conversion of other

• physical form in the one-pot two-step mechanochemical procedure. Optimised conditions for the one-pot synthesis. Substrate scope of the one-pot, 2 step mechanochemical synthesis (isolated yields). a1 equiv Selectfluor used. Optimisation of pyrazolone formation. Optimisation of pyrazolone fluorination

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• mechanochemistry [31], mechanistic aspects [32], mechanochemical synthesis of inorganic material [33], co-crystals [34], metal–ligand complexes [35], metal organic frameworks [36], polymers [37], etc. are well documented in seminal reviews and will not be discussed here. The organic mechanochemistry has remained

• are mixed to finely powdered form for better mixing. The ball-milling chemistry can better be conceived as the updated and sophisticated version of traditional grinding chemistry [38]. Mechanochemical synthesis of C–C bond More atom economic, energy efficient, time efficient and mild syntheses of C–C

• Reaction Pecharsky and co-workers reported the solvent-free mechanochemical synthesis of phosphonium salts [54] and phosphorus ylides [55] in the presence of the weak base K2CO3. Mechanochemically prepared phosphorous ylide from triphenylphosphine in presence of K2CO3 was utilized for a one-pot solvent

Influence of the milling parameters on the nucleophilic substitution reaction of activated β-cyclodextrins

• László Jicsinszky,
• Kata Tuza,
• Giancarlo Cravotto,
• Andrea Porcheddu,
• Francesco Delogu and
• Evelina Colacino

Beilstein J. Org. Chem. 2017, 13, 1893–1899, doi:10.3762/bjoc.13.184

• ]. Despite the longer milling times, using less balls allow outcomes to be improved [14]. This work takes the above-mentioned results as a base from which to address the mechanochemical synthesis of 6I-monoazido-6I-monodeoxy-β-CD and 6I-S-monodeoxy-6I-monothiouronium-β-CD tosylate (TU-β-CD), an important CD

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178

• Raman spectroscopy was devised [27]. Finally, these two in situ techniques have been successfully merged to allow simultaneous monitoring of mechanochemical reactions by PXRD and Raman spectroscopy [28][29]. Review Mechanochemical synthesis of (thio)ureas Thioureas In a paper by Kaupp et al. a study on

• ]. Inspired by these findings, our group decided to explore the reactivity pattern of aromatic and aliphatic amines and aromatic isothiocyanates during mechanochemical synthesis of 49 symmetrical and non-symmetrical N,N'-disubstituted thioureas [32]. For this purpose, a range of amines and isothiocyanates

• by recrystallization from a hexane/ethyl acetate mixture gave previously unrecognized but highly stable 1:1 ethyl acetate solvate, the mechanochemical synthesis led to the pure non-solvated catalyst. The mechanochemically prepared achiral thiourea 5 as well as enantiomers (1R,2R)-8 and (1S,2S)-8 were

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

• a precedence in the application of weaker base in mechanochemical synthesis of triphenylphosphoranes [32]. Often DMF is used as solvent in imide alkylation reactions, which promotes SN2 reactions [33] and its low volatility is advantageous over more environmentally friendly solvents which might be

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

• ; isoeugenol; mechanochemical synthesis; non-enzymatic process; vanillin; Introduction Vanillin is the main flavor and aroma compound in vanilla. It is an aromatic compound (4-hydroxy-3-methoxybenzaldehyde) containing two reactive functional groups that are useful for the synthesis of thermoplastic polymers

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

• solvent within short reaction times of only few minutes [32][35]. A mechanochemical synthesis also enables high yields, making it a promising approach to obtain carbons and carbon precursors [36][37]. So far, mechanochemical reactions for the synthesis of porous carbon materials have rarely been used [38

• -defined pore-size distribution. The material was further investigated as supercapacitor electrode using organic and ionic liquid electrolytes (Figure 1). Results and Discussion Mechanochemical synthesis of the polymeric precursor For a typical synthesis, ethylene glycol (EG), citric acid (CA), and

• hierarchical porous carbons After the mechanochemical synthesis, we conducted a carbochlorination reaction, leading to the carbonization of the precursor and the removal of the dispersed titanium species (Equation 1). This process is comparable to the industrial Kroll process and responsible for the generation

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

• formation In 2009, Alvarez-Nunez et al. of Amgen used TSE to scale up the synthesis of a cocrystal which had already been reported to be synthesised successfully by ball milling (employing liquid-assisted grinding (LAG)). This was the first example demonstrating that mechanochemical synthesis could be

• and usage of MOFs increases, the manufacture of these materials, which typically require solvothermal techniques, has become a key research area. Mechanochemical synthesis of several MOFs has been reported typically by ball milling [48], and James et al. have scaled up the synthesis of HKUST-1, ZIF-8

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

• 31 in Table 1) was not performed because the batch size was in the range of our solution reaction. Mechanochemical synthesis was much more efficient than conventional solution methods. The final temperature was considerably lower (entry 31 vs 30 in Table 1) and the reaction time was dramatically

Expeditious, mechanochemical synthesis of BODIPY dyes

• Laramie P. Jameson and
• Sergei V. Dzyuba

Beilstein J. Org. Chem. 2013, 9, 786–790, doi:10.3762/bjoc.9.89

• be more facile at higher concentrations and probably most efficient under neat conditions. All the subsequent steps should also, in principle, benefit from high concentrations. Results and Discussion As a trial reaction, we attempted a mechanochemical synthesis of BODIPY dye 1 [12] with commonly used