One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: theoretical evidence for an asynchronous concerted pathway

• Esra Demir,
• Ozlem Sari,
• Yasin Çetinkaya,
• Ufuk Atmaca,
• Safiye Sağ Erdem and
• Murat Çelik

Beilstein J. Org. Chem. 2020, 16, 1805–1819, doi:10.3762/bjoc.16.148

• phenyl, benzyl and fused cyclic alkyl groups in different solvents under mild reaction conditions without additives and catalysts was studied. Oxazolidinones and five-membered cyclic carbonates were obtained in ratios close to 1:1 in the cyclization reactions. The best yields of these compounds were

• obtained in dichloromethane (DCM). Together with 16 known compounds, two novel oxazolidinone derivatives and two novel cyclic carbonates were synthesized with an efficient and straightforward method. Compared to the existing methods, the synthetic approach presented here provides the following distinct

• . The further investigation of the potential energy surfaces associated with two possible channels leading to oxazolidinones and five-membered cyclic carbonates disclosed that the cycloaddition reaction proceeds via an asynchronous concerted mechanism in gas phase and in DCM. Keywords: chlorosulfonyl

1,2,3-Triazolium macrocycles in supramolecular chemistry

• Mastaneh Safarnejad Shad,
• Pulikkal Veettil Santhini and
• Wim Dehaen

Beilstein J. Org. Chem. 2019, 15, 2142–2155, doi:10.3762/bjoc.15.211

• nanoreactor because there is an acceleration of the dimerization by two orders of magnitude and the turnover of the catalyst was demonstrated. The synthesis of cyclic carbonates from epoxides and CO2 is an efficient method for CO2 fixation. The development of an effective chiral catalyst for the efficient

• binaphthyl system and the Lewis acidic metal center facilitated the enantioselective synthesis of cyclic carbonates from epoxides. Various catalyst was screened by changing the linker length (n = 4 to 8) and nucleophilic counter anion (X = I, Cl, Br), and 16c was found to be the best catalyst for the

• of the substrate scope showed that various epoxides reacted under the optimized conditions to yield optically active cyclic carbonates and epoxides [63]. 4. pH sensitive 1,2,3-triazolium macrocycles Various macrocycles show remarkable response to the pH of the environment. In the following section

Mechanochemical synthesis of poly(trimethylene carbonate)s: an example of rate acceleration

• Sora Park and
• Jeung Gon Kim

Beilstein J. Org. Chem. 2019, 15, 963–970, doi:10.3762/bjoc.15.93

• polymerization of cyclic carbonates, such as trimethylene carbonate (TMC) and its derivatives have been used for the controlled synthesis of high-molecular weight polymers. Among many catalysts, organocatalysts have attracted considerable attention, since the use of nontoxic catalysts warrants a safe use in

• biomedical applications [24]. The amidine base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is one of the best studied and most popular organocatalysts for ring-opening polymerizations of cyclic carbonates and lactones [25][26][27]. In contrast to the high activity of lactone polymerization, cyclic carbonate

• lactides and cyclic carbonates [27][33]. As expected, TBD effectively promoted the polymerization of trimethylene carbonate both, in solution and under solvent-free ball-milling conditions. Nearly quantitative conversions into polymer were achieved within only 5 min (Table 4). Interestingly, TBD-based ball

Systematic synthetic study of four diastereomerically distinct limonene-1,2-diols and their corresponding cyclic carbonates

• Hiroshi Morikawa,
• Jun-ichi Yamaguchi,
• Shun-ichi Sugimura,
• Masato Minamoto,
• Yuuta Gorou,
• Hisatoyo Morinaga and
• Suguru Motokucho

Beilstein J. Org. Chem. 2019, 15, 130–136, doi:10.3762/bjoc.15.13

• , syntheses of five-membered cyclic carbonates (5CCs) have been intensively investigated [5][6][7] in terms of utilisation of CO2 and the further reactions to produce functional chemicals such as oxazolizin-2-ones [8] and polyurethanes [9]. For (R)-limonene-derived 5CC (LM5CC), four diastereomers are

• ; however, a large coupling constant was clearly observed in CD3OD and in benzene-d6 (Supporting Information File 1, page S42). Conclusion Four diastereomers of (R)-limonene-derived diols (LMdiols) and the corresponding five-membered cyclic carbonates (LM5CCs) were synthesised and characterised by NMR

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

• was achieved along with an effective recycle of the catalyst [17], ii) the formation of six-membered cyclic carbonates by the transesterification of dialkyl carbonates with trimethylolpropane. The products were achieved in high yields (85%) and used as monomers for polyurethanes and polycarbonates [18

• synthesize organic carbonates consists in the acid or base-catalyzed transesterification of dimethyl carbonate (DMC), the simplest organic carbonate, with alcohols R–OH or diols to yield either acyclic organic carbonates or cyclic carbonates, respectively (Scheme 8). A literature survey on the synthesis of

• corresponding cyclic carbonates, while 1,3-diols, depending on their structures, could yield both, cyclic or acyclic carbonates, such as the ones shown in Scheme 19 [75]. There is no direct relation of the performance of these IL-catalysts to their basicity. Curiously, it should be noted that the activity of

Robust bifunctional aluminium–salen catalysts for the preparation of cyclic carbonates from carbon dioxide and epoxides

• Yuri A. Rulev,
• Zalina Gugkaeva,
• Victor I. Maleev,
• Michael North and
• Yuri N. Belokon

Beilstein J. Org. Chem. 2015, 11, 1614–1623, doi:10.3762/bjoc.11.176

• catalysts induced the formation of cyclic carbonates under mild reaction conditions (25–35 °C; 1–10 bar carbon dioxide pressure). However, with cyclohexene oxide under the same reaction conditions, the same catalysts induced the formation of polycarbonate. The catalysts could be recovered from the reaction

• achieving this goal is to produce cyclic carbonates or polycarbonates from carbon dioxide and the corresponding epoxides (Scheme 1). Cyclic carbonates are an important class of solvents [2] and starting materials in organic synthesis [3][4][5][6]. Although a significant array of catalysts have been

• developed for the production of cyclic carbonates [7][8][9] and polycarbonates [10][11] from carbon dioxide and epoxides, the most developed and privileged set of catalysts are based on Lewis acidic metal–salen complexes. In particular, cobalt(III) and chromium(III) complexes were found to be highly

Surprisingly facile CO₂ insertion into cobalt alkoxide bonds: A theoretical investigation

• Willem K. Offermans,
• Claudia Bizzarri,
• Walter Leitner and
• Thomas E. Müller

Beilstein J. Org. Chem. 2015, 11, 1340–1351, doi:10.3762/bjoc.11.144

• CO2, active and selective catalysts for these reactions are scarce [9]. The reaction of CO2 with epoxides yields alternating polycarbonates, polyethercarbonates or cyclic carbonates (Scheme 1). The production of CO2-based polymers is considerably more challenging compared to the formation of cyclic

• – [13][14][15][16][17][18] and cobalt–salen complexes [19][20][21][22] and heterogeneous double metal cyanide (DMC) catalysts [11][23][24][25][26]. In comparison, industrially well-established catalysts are available to accelerate the production of cyclic carbonates [27][28][29]. As the CO2-based

• polymers are thermodynamically less stable than cyclic carbonates, a kinetic control must be attained to direct the reaction to the polymeric products. To selectively lower the activation barrier towards polycarbonates, a rational development of suitable catalysts is essential. This current study aims to

CO₂ Chemistry

• Thomas E. Müller and
• Walter Leitner

Beilstein J. Org. Chem. 2015, 11, 675–677, doi:10.3762/bjoc.11.76

• fixation of CO2, which can be applied in the synthesis of carboxylic acids [8]. Also highly interesting is the combination of enzymatic and photocatalytic approaches for activating CO2 [9]. Bifunctional catalyst systems are frequently needed and well-understood in the synthesis of cyclic carbonates [10

Electrocarboxylation: towards sustainable and efficient synthesis of valuable carboxylic acids

• Roman Matthessen,
• Jan Fransaer,
• Koen Binnemans and
• Dirk E. De Vos

Beilstein J. Org. Chem. 2014, 10, 2484–2500, doi:10.3762/bjoc.10.260

• temperatures and pressures to activate CO2 [2][3]. Efficient chemical incorporation of CO2 is limited to rather reactive substrates, like epoxides [4][5][6] and amines [7][8][9] to produce cyclic carbonates and carbamates, respectively, and even then, elevated reaction temperatures and/or complex catalyst

Comparing kinetic profiles between bifunctional and binary type of Zn(salen)-based catalysts for organic carbonate formation

• Carmen Martín and
• Arjan W. Kleij

Beilstein J. Org. Chem. 2014, 10, 1817–1825, doi:10.3762/bjoc.10.191

• employed as active catalysts for the formation of cyclic carbonates from epoxides and CO2. A series of kinetic experiments was carried out to obtain information about the mechanism for this process catalyzed by these complexes and in particular about the order-dependence in catalyst. A comparative analysis

• opposed to the binary catalyst that is connected with a first-order dependence on the catalyst concentration and a monometallic mechanism. Keywords: CO2 chemistry; cyclic carbonates; kinetic studies; salen complexes; zinc; Introduction Carbon dioxide may be regarded as an ideal, renewable carbon feed

• stock for the synthesis of organic compounds being also of interest in an industrial context [1][2][3][4][5]. This inexpensive, abundant and nontoxic source of carbon has been extensively used to convert epoxides into their respective cyclic carbonates [6][7][8][9] (Scheme 1), that find useful

Photoreactions of cyclic sulfite esters: Evidence for diradical intermediates

• Rick C. White,
• Benny E. Arney Jr. and
• Heiko Ihmels

Beilstein J. Org. Chem. 2012, 8, 1208–1212, doi:10.3762/bjoc.8.134

• cyclic carbonates 1a and 1b (Scheme 1) generate products derived from 1,3-diradical intermediates [14]. Interestingly, the photoinduced fragmentation reactions of nitrogen- and oxygen-containing functionalities have been studied intensively, whereas reports on photoextrusion reactions of sulfur

• because of its rapid secondary reaction. However, oxiranes have been observed as persistent intermediates under essentially identical conditions during photolysis of cyclic carbonates 1a and 1b, thus it is unlikely that they are formed to a significant extent in the photoreaction of 8. Similarly, we

• investigated the photochemistry of hydrobenzoin sulfite (9), which has been reported also to be a carbene precursor [16]. Because it has been shown in the case of cyclic carbonates that the application of milder reaction conditions enables the detection of reaction products that apparently decompose under

Aldol elaboration of 4,5,6,7-tetrahydroisoxazolo[4,3-c]pyridin-4-ones, masked precursors to acylpyridones

• Raymond C. F. Jones,
• Abdul K. Choudhury,
• James N. Iley,
• Mark E. Light,
• Georgia Loizou and
• Terence A. Pillainayagam

Beilstein J. Org. Chem. 2012, 8, 308–312, doi:10.3762/bjoc.8.33

• four steps by the route shown in Scheme 3, involving palladium-catalysed decarboxylative ring opening of cyclic carbonates [23]. Thus the enolate of α-tetralone was added to propenal in an aldol addition (LDA, THF, −78 °C; 86%). The second step involved the reduction of the intermediate β-hydroxyketone

When gold can do what iodine cannot do: A critical comparison

• Sara Hummel and
• Stefan F. Kirsch

Beilstein J. Org. Chem. 2011, 7, 847–859, doi:10.3762/bjoc.7.97

• trapped with internal nucleophiles. For example, Shin and co-workers reported a valuable transformation using the tert-butoxycarbonyl (Boc) group to trap the cation following the activation of π-systems by gold in a route to cyclic carbonates (Scheme 10a) [100]. The Boc-group was considered to be very

Kinetics and mechanism of vanadium catalysed asymmetric cyanohydrin synthesis in propylene carbonate

• Michael North and
• Marta Omedes-Pujol

Beilstein J. Org. Chem. 2010, 6, 1043–1055, doi:10.3762/bjoc.6.119

• chlorinated solvents, optimally dichloromethane. Recently however, we showed that catalyst 2 could be used in propylene carbonate [53]. Propylene carbonate and other cyclic carbonates are starting to attract significant interest as green solvents [54][55][56][57][58][59][60][61][62][63][64], since they can be

• . Synthesis of cyclic carbonates. Synthesis of cyanohydrin trimethylsilyl ethers and acetates. Equilibrium between bimetallic and monometallic Ti(salen) complexes. Influence of solvent on cyanohydrin synthesis using catalysts 1 and 2. Optimization of asymmetric cyanohydrin synthesis catalysed by complex 2 in