A versatile way for the synthesis of monomethylamines by reduction of N-substituted carbonylimidazoles with the NaBH₄/I₂ system

• Lin Chen,
• Xuan Zhou,
• Zhiyong Chen,
• Changxu Wang,
• Shunjie Wang and
• Hanbing Teng

Beilstein J. Org. Chem. 2022, 18, 1032–1039, doi:10.3762/bjoc.18.104

• chemicals, agrochemicals, pharmaceuticals and dyes [1][2][3][4]. Traditional methods for the preparation of N-methylamines involve the direct methylation of amines by using methyl halides [5][6][7], dimethyl sulfate [8], diazomethane [9], methyl triflate [10][11] or dimethyl carbonate [12][13][14][15] as

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

• Pezhman Shiri,
• Ali Mohammad Amani and
• Thomas Mayer-Gall

Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114

• , high yield, the use of dimethyl carbonate as a sustainable solvent, the use of an efficient alternative source of carbon monoxide, and avoiding a pressurized cylinder are some benefits of this protocol (Scheme 35) [59]. A feasible mechanism is illustrated for the synthesis of 1,2,3-triazole-5

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Chan–Evans–Lam N1-(het)arylation and N1-alkеnylation of 4-fluoroalkylpyrimidin-2(1H)-ones

• Viktor M. Tkachuk,
• Oleh O. Lukianov,
• Mykhailo V. Vovk,
• Isabelle Gillaizeau and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2020, 16, 2304–2313, doi:10.3762/bjoc.16.191

• . Average product yields of 38–69% were observed for the reaction run in methanol, dichloroethane, tetrahydrofuran, and ethyl acetate (Table 1, entries 13–15, 20 and 21). In dimethyl carbonate and DMSO solutions, the yields were reduced to 4 and 11%, respectively (Table 1, entries 22 and 23). In contrast

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

KOt-Bu-promoted selective ring-opening N-alkylation of 2-oxazolines to access 2-aminoethyl acetates and N-substituted thiazolidinones

• Qiao Lin,
• Shiling Zhang and
• Bin Li

Beilstein J. Org. Chem. 2020, 16, 492–501, doi:10.3762/bjoc.16.44

• solvents, including toluene, EtOH, THF, H2O, CH2Cl2 and dimethyl carbonate (DMC). Among them, DMC afforded the product 3a in an excellent yield and as greener solvent compared to CH3CN, it was selected as the best solvent for this ring-opening N-alkylation (Table 1, entry 11). When replacing KOt-Bu by

Green synthesis of new chiral 1-(arylamino)imidazo[2,1-a]isoindole-2,5-diones from the corresponding α-amino acid arylhydrazides in aqueous medium

• Nadia Bouzayani,
• Jamil Kraїem,
• Sylvain Marque,
• Yakdhane Kacem,
• Abel Carlin-Sinclair,
• Jérôme Marrot and
• Béchir Ben Hassine

Beilstein J. Org. Chem. 2018, 14, 2923–2930, doi:10.3762/bjoc.14.271

• conditions, we investigated the reaction in nontoxic solvents such as water and dimethyl carbonate (DMC). Indeed, DMC is well-known as safe reagent and solvent that has been used for many green applications [31][32][33]. On the other hand, water is a simply and environmentally benign solvent and interest has

Synthesis of a tyrosinase inhibitor by consecutive ethenolysis and cross-metathesis of crude cashew nutshell liquid

• Jacqueline Pollini,
• Valentina Bragoni and
• Lukas J. Gooßen

Beilstein J. Org. Chem. 2018, 14, 2737–2744, doi:10.3762/bjoc.14.252

• including sustainable solvents like dimethyl carbonate and p-cymene. Unfortunately, this led to a decreased conversion and just 44–47% yield of the desired product. The use of the halogenated solvent dichloromethane was still most efficient. Comparative tests with varying amounts of 1-hexene revealed that

Direct electrochemical generation of organic carbonates by dehydrogenative coupling

• Tile Gieshoff,
• Vinh Trieu,
• Jan Heijl and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2018, 14, 1578–1582, doi:10.3762/bjoc.14.135

• carbonates like diphenyl carbonate (DPC) or dimethyl carbonate (DMC) are key intermediates. Processes for the carbonate generation have been investigated since the 1950s [2]. Although the use of these starting materials is straightforward and unobjectionable at first sight, their generation usually requires

A concise flow synthesis of indole-3-carboxylic ester and its derivatisation to an auxin mimic

• Marcus Baumann,
• Ian R. Baxendale and
• Fabien Deplante

Beilstein J. Org. Chem. 2017, 13, 2549–2560, doi:10.3762/bjoc.13.251

• recrystallization from DCM to give a white amorphous powder of high purity in 82% yield. A series of attempts to employ dimethyl carbonate as a replacement reagent for CDI in the final step failed under a range of conditions as did trials to directly utilise (methoxycarbonyl)hydrazide (CAS 6294-89-9) in the

Continuous N-alkylation reactions of amino alcohols using γ-Al₂O₃ and supercritical CO₂: unexpected formation of cyclic ureas and urethanes by reaction with CO₂

• Emilia S. Streng,
• Darren S. Lee,
• Michael W. George and
• Martyn Poliakoff

Beilstein J. Org. Chem. 2017, 13, 329–337, doi:10.3762/bjoc.13.36

• catalyst that is often overlooked and it is used merely as a support for other catalysts [39][40][41][42][43]. The use of γ-alumina for the methylation of aniline with dimethyl carbonate has been reported [44]. In this paper, we chose to study the intramolecular and intermolecular alkylation of amino

Isosorbide and dimethyl carbonate: a green match

• Fabio Aricò and
• Pietro Tundo

Beilstein J. Org. Chem. 2016, 12, 2256–2266, doi:10.3762/bjoc.12.218

• isosorbide with green reagents and solvent dimethyl carbonate (DMC) is reported. Dehydration of D-sorbitol via DMC in the presence of catalytic amounts of base is an efficient and viable process for the preparation of the industrially relevant anhydro sugar isosorbide. This procedure is “chlorine-free”, one

• reactivity of isosorbide and the non-toxic properties of DMC represent indeed a green match leading to several industrial appealing potential applications. Keywords: carbohydrate chemistry; D-sorbitol; dimethyl carbonate; green chemistry; isosorbide; Review Introduction In the last twenty years biorefinery

• carbonate (DMC). Dimethyl carbonate, the simplest among the dialkyl carbonate (DAC) family, is nowadays produced by a clean and halogen-free process [21][22][23]. This compound has been extensively employed as green substitute of highly toxic phosgene in carboxymethylation reactions and methyl halides or

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• products such as shells and even livestock bones [11][12][13][14]. However, traditional catalysts such as alkali hydroxides or alkaline methoxides are still encountered even for novel syntheses of biofuels. An example is the transesterification of oils by dimethyl carbonate (DMC) in the presence of KOH

• the 1980’s, the industrial synthesis of the simplest representative of the series, dimethyl carbonate (DMC), was based on the phosgenation of methanol, which used a lethal chemical reagent such as phosgene (Scheme 6, top). Since then, the processes for the production of DMC have progressively evolved

• distillation reactor loaded with quaternary ammonium strongly basic anion exchange resin and alkali hydroxides: dimethyl carbonate (DMC) is achieved in practically quantitative yields (Scheme 6, bottom). The third and final step is the transesterification of DMC with phenol by a catalytic reactive distillation

Towards the total synthesis of keramaphidin B

• Pavol Jakubec,
• Alistair J. M. Farley and
• Darren J. Dixon

Beilstein J. Org. Chem. 2016, 12, 1096–1100, doi:10.3762/bjoc.12.104

• -valerolactone (10) with dimethyl carbonate, using LHMDS as the base, in 83% yield. The furanyl nitroolefin 11 was readily synthesised on multigram scale via a Henry condensation, according to literature procedures [20]. We were delighted to observe that the Michael addition reaction using our previously

Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

• Tatjana Huber,
• Lara Weisheit and
• Thomas Magauer

Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273

• isobutene (36), an isomeric mixture of trans- and cis-fused [4.2.0]octanone was obtained (trans-38/cis-39 = 4:1). The more stable cis-bicycle 39 could be obtained by isomerization of trans-38 with base. Acylation with sodium hydride and dimethyl carbonate followed by methylation furnished β-keto ester 40

Cross metathesis of unsaturated epoxides for the synthesis of polyfunctional building blocks

• Meriem K. Abderrezak,
• Kristýna Šichová,
• Nancy Dominguez-Boblett,
• Antoine Dupé,
• Zahia Kabouche,
• Christian Bruneau and
• Cédric Fischmeister

Beilstein J. Org. Chem. 2015, 11, 1876–1880, doi:10.3762/bjoc.11.201

• necessary to ensure high conversion. Reactions were carried out in dimethyl carbonate (DMC), a solvent compatible with ruthenium olefin metathesis catalysts [28] while being much greener than toluene or dichloromethane commonly used in such reactions [29]. Based on our previous results and observations in

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

• an iodine mediated aromatisation, followed by high temperature mono-methylation using dimethyl carbonate/dimethylimidazole as a more benign alternative to methyl iodide at scale. The subsequent Claisen condensation step between ketone 112 and diethyl oxalate (113) was reportedly hampered by product

Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts

• Jong Yeob Jeon,
• Seong Chan Eo,
• Jobi Kodiyan Varghese and
• Bun Yeoul Lee

Beilstein J. Org. Chem. 2014, 10, 1787–1795, doi:10.3762/bjoc.10.187

• units [poly(1,4-butylene terephthalate-co-carbonate)], prepared by condensation polymerization of 1,4-butanediol, dimethyl terephthalate, and dimethyl carbonate, has also been reported recently [35][36]. When ethanol (5.0 mg, 60 equiv/1) was fed as a chain-transfer agent with 1.0 g PA, faster PA

1-n-Butyl-3-methylimidazolium-2-carboxylate: a versatile precatalyst for the ring-opening polymerization of ε-caprolactone and rac-lactide under solvent-free conditions

• Astrid Hoppe,
• Faten Sadaka,
• Claire-Hélène Brachais,
• Gilles Boni,
• Jean-Pierre Couvercelle and
• Laurent Plasseraud

Beilstein J. Org. Chem. 2013, 9, 647–654, doi:10.3762/bjoc.9.73

• . In this quest and encouraged by our previous results, we chose to explore the potential of zwitterionic 1-n-butyl-3-methylimidazolium-2-carboxylate (BMIM-2-CO2, Figure 1). Indeed, methylimidazolium-2-carboxylates can be easily synthesized with high yields by the one-pot reaction of dimethyl carbonate

• , its facile preparation, in only one-step with a satisfactory yield (66%) and from commercial n-butylimidazole and dimethyl carbonate, increases its attractiveness and its green character compared to the direct use of stable and active N-heterocarbenes, which require several synthetic steps [59

Ene–yne cross-metathesis with ruthenium carbene catalysts

• Cédric Fischmeister and
• Christian Bruneau

Beilstein J. Org. Chem. 2011, 7, 156–166, doi:10.3762/bjoc.7.22

• been carried out in our group using dimethyl carbonate (DMC) as solvent (Scheme 20) [86]. The ethenolysis cleavage was performed in the presence of catalyst III, which led to 93% conversion of the starting oleate and selective production of dec-1-ene and methyl undec-9-enoate with trace amounts of