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Search for "solvent-free conditions" in Full Text gives 143 result(s) in Beilstein Journal of Organic Chemistry.

Rearrangements of organic peroxides and related processes

  • Ivan A. Yaremenko,
  • Vera A. Vil’,
  • Dmitry V. Demchuk and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

Graphical Abstract
  • -dioxolanes 151 are rearranged similarly to the Criegee mechanism into diketone derivatives 152 (Scheme 44) [298]. Unlike the Baeyer–Villiger rearrangement, in which only mono-O-insertion can take place, the Criegee rearrangement of peroxide 153 in an acidic medium and under solvent-free conditions does not
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Published 03 Aug 2016

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

  • Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

Graphical Abstract
  • substituted isatins 30 with aniline (32) and dimethyl- or diethyl phosphite under solvent-free conditions in the presence of magnetic Fe3O4 nanoparticle-supported phosphotungstic acid as a recyclable catalyst at 80 °C furnished α-aminophosphonates 33 in yields from 80% to 98% depending on the reaction time
  • -methyl-3-formylchromone (75) with some 1,2-, 1,3- and 1,4-bi-nucleophiles and diethyl phosphonate under solvent-free conditions have been developed by E. Ali et al. [46]. The resulting α-aminophosphonate intermediates 77 and 80 were non-isolable and interconverted to the corresponding heterocyclic
  • 1,2-dihydropyridine-3-phosphonate 259. Yavari et al. have described the phosphorylation of benzothiazole (263) and isoquinoline (246) through a one-pot three-component reaction with activated acetylenes 260 and diphenyl phosphonate (261) under solvent-free conditions at room temperature (Scheme 54
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Published 21 Jun 2016

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

Graphical Abstract
  • (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
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Published 01 Apr 2016

(Thio)urea-mediated synthesis of functionalized six-membered rings with multiple chiral centers

  • Giorgos Koutoulogenis,
  • Nikolaos Kaplaneris and
  • Christoforos G. Kokotos

Beilstein J. Org. Chem. 2016, 12, 462–495, doi:10.3762/bjoc.12.48

Graphical Abstract
  • screening of various catalysts, organocatalyst 43 and 4-methoxybenzoic acid as a cocatalyst, was identified as the optimum for the reaction of (E)-2-nitroallyl acetate 40 with cyclohexanone 41 to provide nitrobicyclo[3.3.1]nonan-9-one 42, in solvent-free conditions. This reaction provides products with
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Published 10 Mar 2016

Enantioselective additions of copper acetylides to cyclic iminium and oxocarbenium ions

  • Jixin Liu,
  • Srimoyee Dasgupta and
  • Mary P. Watson

Beilstein J. Org. Chem. 2015, 11, 2696–2706, doi:10.3762/bjoc.11.290

Graphical Abstract
  • report is the first and only example to date of alkynylation of an imine or iminium ion to form a chiral tetrasubstituted center with high ee. Enantioselective, copper-catalyzed alkynylations have also been accomplished under solvent-free conditions. In 2013, Su and co-workers established that the CDC
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Published 22 Dec 2015

Efficient synthetic protocols for the preparation of common N-heterocyclic carbene precursors

  • Morgan Hans,
  • Jan Lorkowski,
  • Albert Demonceau and
  • Lionel Delaude

Beilstein J. Org. Chem. 2015, 11, 2318–2325, doi:10.3762/bjoc.11.252

Graphical Abstract
  • and ZnCl2. This Friedel–Crafts alkylation was carried out under solvent-free conditions and afforded high yields of the bulky aniline needed to follow the Arduengo formylative cyclization path. It was originally performed in a sealed tube under autogeneous pressure at 160 °C. We checked that the
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Published 25 Nov 2015

Olefin metathesis in air

  • Lorenzo Piola,
  • Fady Nahra and
  • Steven P. Nolan

Beilstein J. Org. Chem. 2015, 11, 2038–2056, doi:10.3762/bjoc.11.221

Graphical Abstract
  • % of Ru at 150 °C in air, under solvent-free conditions for several days, to afford 1,2-bis(silyl)ethenes in moderate to good yields [33]. Reactions without oxygen showed no conversion, highlighting the important role that the latter plays in the activation of the catalyst. In 1992, Grubbs and co
  • 2nd generation catalyst (33) and a variation of the latter (66, Figure 8) in the RCM of diethyl diallylmalonate (29) [66]. Reactions were performed with very low catalyst loading (from 2.5 to 0.04 mol %), at 30 °C, under air in nondegassed DCM, nondegassed methyl decanoate and under solvent-free
  • conditions in nondegassed substrates. Full conversions were achieved in the majority of cases, in both CM and RCM reactions, with all catalysts. In these reactions, catalyst 66 gave the highest performance. It should be noted that the results obtained by Meier with 33 were in contrast with the previous
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Published 30 Oct 2015

Investigation on the reactivity of α-azidochalcones with carboxylic acids: Formation of α-amido-1,3-diketones and highly substituted 2-(trifluoromethyl)oxazoles

  • Kandasamy Rajaguru,
  • Arumugam Mariappan,
  • Rajendran Suresh,
  • Periasamy Manivannan and
  • Shanmugam Muthusubramanian

Beilstein J. Org. Chem. 2015, 11, 2021–2028, doi:10.3762/bjoc.11.219

Graphical Abstract
  • temperature, it affords highly substituted 2-(trifluoromethyl)oxazoles. These flexible transformations proceed under solvent free conditions in good to excellent yields without any catalyst. Keywords: α-amido-1,3-diketones; α-azidochalcones; carboxylic acids; 2H-azirines; oxazoles; Introduction α
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Published 29 Oct 2015

Aerobic addition of secondary phosphine oxides to vinyl sulfides: a shortcut to 1-hydroxy-2-(organosulfanyl)ethyl(diorganyl)phosphine oxides

  • Svetlana F. Malysheva,
  • Alexander V. Artem’ev,
  • Nina K. Gusarova,
  • Nataliya A. Belogorlova,
  • Alexander I. Albanov,
  • C. W. Liu and
  • Boris A. Trofimov

Beilstein J. Org. Chem. 2015, 11, 1985–1990, doi:10.3762/bjoc.11.214

Graphical Abstract
  • Chemistry, National Dong Hwa University, Hualien 97401, Taiwan 10.3762/bjoc.11.214 Abstract Secondary phosphine oxides react with vinyl sulfides (both alkyl- and aryl-substituted sulfides) under aerobic and solvent-free conditions (80 °C, air, 7–30 h) to afford 1-hydroxy-2-(organosulfanyl)ethyl(diorganyl
  • addition of P–H species to the C=C bonds readily proceeds in the absence of any catalyst or initiator (Scheme 1). The reactions occur under mild solvent-free conditions (70–80 °C, inert atmosphere, 3–15 h) to chemo- and regioselectively furnish the anti-Markovnikov adducts in excellent yields (up to 99
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Published 23 Oct 2015

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

Graphical Abstract
  • free conditions. Catalyst recycling experiments are also reported and show the robustness of this system. Results and Discussion The preparation of salen ligands 8a and 8b was conducted according to Scheme 2, starting from tert-butylphenol, which was formylated and then nitrated to produce 5-nitro-3
  • salts and increasing the steric hindrance around the ammonium salts. Herein, we report the synthesis of two aluminium–salen complexes incorporating quaternary ammonium salts directly attached to the salen ligand and their catalytic activities for the coupling of epoxides and carbon dioxide under solvent
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Published 11 Sep 2015

Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ

  • Raúl García,
  • M. Ángeles Herranz,
  • Edmund Leary,
  • M. Teresa González,
  • Gabino Rubio Bollinger,
  • Marius Bürkle,
  • Linda A. Zotti,
  • Yoshihiro Asai,
  • Fabian Pauly,
  • Juan Carlos Cuevas,
  • Nicolás Agraït and
  • Nazario Martín

Beilstein J. Org. Chem. 2015, 11, 1068–1078, doi:10.3762/bjoc.11.120

Graphical Abstract
  • -free conditions as recently reported [27]. Hence, as a starting point, we followed the same sample preparation conditions as previously with the OPE3-dithiol [27]. We prepared 0.1–1 mM solutions of compound 5 in both 1,2,4-trichlorobenzene (TCB) or mesitylene/tetrahydrofuran (Mes/THF 4:1), and exposed
  • -dithiol compound (where 3 indicates the total number of phenyl rings), in which the central phenyl ring has been substituted by an exTTF unit. We could, therefore, expect compound 5 to form molecular junctions in a similar way to the OPE3-dithiol, which readily does so either in solution, or under solvent
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Published 24 Jun 2015

On the strong difference in reactivity of acyclic and cyclic diazodiketones with thioketones: experimental results and quantum-chemical interpretation

  • Andrey S. Mereshchenko,
  • Alexey V. Ivanov,
  • Viktor I. Baranovskii,
  • Grzegorz Mloston,
  • Ludmila L. Rodina and
  • Valerij A. Nikolaev

Beilstein J. Org. Chem. 2015, 11, 504–513, doi:10.3762/bjoc.11.57

Graphical Abstract
  • diazo compounds 1a–f with cycloaliphatic thioketone 2b were calculated (Table 2). All calculations refer to the gas phase, since all reactions of DDC 1 with the thioxocyclobutanedione 2b were carried out under solvent-free conditions [20]. The driving force behind the DDC 1a–d reactions with
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Published 20 Apr 2015

A green approach to the synthesis of novel phytosphingolipidyl β-cyclodextrin designed to interact with membranes

  • Yong Miao,
  • Florence Djedaïni-Pilard and
  • Véronique Bonnet

Beilstein J. Org. Chem. 2014, 10, 2654–2657, doi:10.3762/bjoc.10.278

Graphical Abstract
  • medium. The mixture was left to react for 10 minutes. The use of TLC indicated the end of the reaction. After the purification, yields of above 70% were obtained. It was indeed observed that solvent-free conditions can be employed in this reaction. The reaction is much faster without solvent due to the
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Published 12 Nov 2014

Regio- and stereoselective synthesis of new diaminocyclopentanols

  • Evgeni A. Larin,
  • Valeri S. Kochubei and
  • Yuri M. Atroshchenko

Beilstein J. Org. Chem. 2014, 10, 2513–2520, doi:10.3762/bjoc.10.262

Graphical Abstract
  • experiments was performed under solvent-free conditions at 100 °C. In case of morpholine (7a), the best catalytic effect was observed with LiClO4 [36] and Zn(ClO4)2·6H2O [37] affording 56 and 76% yield of 8a after isolation and purification, therefore the absence of the solvent seems crucial for the reaction
  • nucleophilicity. Moreover, there was not much effect on the outcome of the reactions conducted either under solvent-free conditions or using DMSO as a solvent. The regioisomers 9a–d and 10a–d were isolated through column chromatographic separation and fully characterized in order to avoid ambiguity. The
  • diaminocyclopentanols in good yields. It has been shown that using Zn(ClO4)2·6H2O under solvent-free conditions and Cs2CO3 in DMSO is preferable to the ring opening of di-N-protected cyclopentanamine epoxides. We have highlighted the influence of the nature of the N,N-disubstituted amino moiety and the orientation of
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Published 28 Oct 2014

Multicomponent reactions in nucleoside chemistry

  • Mariola Koszytkowska-Stawińska and
  • Włodzimierz Buchowicz

Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179

Graphical Abstract
  • phosphite were carried out under solvent-free conditions at 60 °C (for 14) or at 80 °C (for 27). Products 28 and 29 were obtained in good to excellent yields as 1:1 diastereoisomeric mixtures arising from the generation of a stereogenic center at the aminophosphonate chain. The mixtures were not separated
  • , microwave irradiation (600 W), 6–10 min (solvent-free conditions). Reagents and reaction conditions: i. Montmorillonite K-10 clay, microwave irradiation (560 W), 6–10 min (solvent-free conditions). Reagents and reaction conditions: i. CeCl3·7H2O (20 mol %), NaI (20 mol %), microwave irradiation (90 °C), 6–8
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Published 29 Jul 2014

Preparation of phosphines through C–P bond formation

  • Iris Wauters,
  • Wouter Debrouwer and
  • Christian V. Stevens

Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106

Graphical Abstract
  • also been shown to take place at room temperature in the absence of a catalyst [86][87] and even under solvent-free conditions [88]. More recently also metal complex-assisted or organocatalyzed hydrophosphinations have been reported. Several reviews focusing on hydrophosphination have been pusblished
  • corresponding triflate under similar conditions [196][197]. The reaction also proceeded under solvent-free conditions with slightly higher yields [198]. A heterogeneous Pd/C catalyst has been applied as well [199][200]. The group of Glueck has reported the first asymmetric palladium-catalyzed C–P bond formation
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Published 09 May 2014

Silver and gold-catalyzed multicomponent reactions

  • Giorgio Abbiati and
  • Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

Graphical Abstract
  • recently, silver–NHC complexes were found to be valuable catalysts for this MCR. Their first application was reported by Wang and co-workers in 2008 [12], who developed a polystyrene-supported NHC–Ag(I) complex as an efficient catalyst for the A3-coupling under solvent-free conditions, at room temperature
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Published 26 Feb 2014

Simple two-step synthesis of 2,4-disubstituted pyrroles and 3,5-disubstituted pyrrole-2-carbonitriles from enones

  • Murat Kucukdisli,
  • Dorota Ferenc,
  • Marcel Heinz,
  • Christine Wiebe and
  • Till Opatz

Beilstein J. Org. Chem. 2014, 10, 466–470, doi:10.3762/bjoc.10.44

Graphical Abstract
  • . Gratifyingly, yield and purity of pyrrole 7a increased when 6a was heated with microwaves to 250 °C under air cooling of the reaction vessel without any additive under solvent-free conditions. The results of the application of these conditions to cyanopyrrolines 6a–j are summarized in Table 1. This compound
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Published 24 Feb 2014

Practical synthesis of aryl-2-methyl-3-butyn-2-ols from aryl bromides via conventional and decarboxylative copper-free Sonogashira coupling reactions

  • Andrea Caporale,
  • Stefano Tartaggia,
  • Andrea Castellin and
  • Ottorino De Lucchi

Beilstein J. Org. Chem. 2014, 10, 384–393, doi:10.3762/bjoc.10.36

Graphical Abstract
  • variants have been introduced to perform efficiently this reaction with regard to synthetic and industrial aspects, including protocols in aqueous media [14][15][16][17], amine-free [18] or solvent-free conditions [19]. Moreover efficient reusable Pd catalysts [20][21][22][23][24] and even palladium-free
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Published 12 Feb 2014

Less reactive dipoles of diazodicarbonyl compounds in reaction with cycloaliphatic thioketones – First evidence for the 1,3-oxathiole–thiocarbonyl ylide interconversion

  • Valerij A. Nikolaev,
  • Alexey V. Ivanov,
  • Ludmila L. Rodina and
  • Grzegorz Mlostoń

Beilstein J. Org. Chem. 2013, 9, 2751–2761, doi:10.3762/bjoc.9.309

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  • intensive red or orange color of thioketone 1. In order to enhance the concentration of the reagents and thereby increase the rate of the reaction, experiments with liquid diazocompounds 2a,c–e,h and i and thioketone 1a were carried out under solvent-free conditions. On the other hand, reactions of solid
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Published 02 Dec 2013

Triol-promoted activation of C–F bonds: Amination of benzylic fluorides under highly concentrated conditions mediated by 1,1,1-tris(hydroxymethyl)propane

  • Pier Alexandre Champagne,
  • Alexandre Saint-Martin,
  • Mélina Drouin and
  • Jean-François Paquin

Beilstein J. Org. Chem. 2013, 9, 2451–2456, doi:10.3762/bjoc.9.283

Graphical Abstract
  • from our solvent-free conditions, which were providing the better results, we envisioned that further optimization was possible to improve the yield (Table 2). First, temperature had an important impact on conversion. Indeed, going from 60 °C (Table 2, entry 1) to 100 °C (Table 2, entry 3) smoothly
  • neutral and solvent-free conditions. To further support this hypothesis, solvent properties concerning their hydrogen bond acidity or basicity correlate well with the experimental evidence of reactivity. Investigations concerning the reaction mechanism and precise role of the three hydroxy groups of 2 for
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Published 13 Nov 2013

Silica sulfuric acid: a reusable solid catalyst for one pot synthesis of densely substituted pyrrole-fused isocoumarins under solvent-free conditions

  • Sudipta Pathak,
  • Kamalesh Debnath and
  • Animesh Pramanik

Beilstein J. Org. Chem. 2013, 9, 2344–2353, doi:10.3762/bjoc.9.269

Graphical Abstract
  • pyrrole-fused isocoumarins, which employs solid-supported silica sulfuric acid (SSA) as catalyst, has been developed. When the mixture of ninhydrin adducts of acetylacetone/ethyl acetoacetate and primary amines was heated on the solid surface of SSA under solvent-free conditions, the pyrrole-fused
  • easily retrievable solid catalyst in various important organic syntheses under solvent-free conditions [25]. The high catalytic activity, the operational simplicity and the recyclability of SSA can be exploited in the industry for the synthesis of various drugs and pharmaceuticals. SSA, a product that is
  • under solvent-free conditions (Scheme 1, present work). Results and Discussion Recently, we have reported that the enamines 3 generated from acetylacetone (1) and amines 2 react with ninhydrin to form the cyclic hemiaminal dihydroxyindenopyrroles 4. Subsequently intermediates 4 produce the pyrrole-fused
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Published 04 Nov 2013

Acid, silver, and solvent-free gold-catalyzed hydrophenoxylation of internal alkynes

  • Marcia E. Richard,
  • Daniel V. Fraccica,
  • Kevin J. Garcia,
  • Erica J. Miller,
  • Rosa M. Ciccarelli,
  • Erin C. Holahan,
  • Victoria L. Resh,
  • Aakash Shah,
  • Peter M. Findeis and
  • Robert A. Stockland Jr.

Beilstein J. Org. Chem. 2013, 9, 2002–2008, doi:10.3762/bjoc.9.235

Graphical Abstract
  • is focused on the elimination of solvents and additives from the synthetic methodology [10]. Thus, the design of gold catalyzed reactions that proceed under solvent-free conditions and without the addition of silver salts or acidic promoters would be of interest to those charged with designing
  • -free conditions [12][13]. To this end, we have synthesized and investigated a series of arylgold compounds as single-component catalysts for hydroelementation reactions under acid, silver, and solvent-free conditions. We recently reported the synthesis of arylgold compounds using a focused microwave
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Published 02 Oct 2013

A3-Coupling catalyzed by robust Au nanoparticles covalently bonded to HS-functionalized cellulose nanocrystalline films

  • Jian-Lin Huang,
  • Derek G. Gray and
  • Chao-Jun Li

Beilstein J. Org. Chem. 2013, 9, 1388–1396, doi:10.3762/bjoc.9.155

Graphical Abstract
  • reaches completion after 24 h under the present conditions. At a lower reaction temperature (25 °C), the Au@HS-CNC(4.4 mol %) showed lower conversion due to an incomplete reaction. We obtained the best conversion at a higher reaction temperature (above 80 °C). Solvent-free conditions proved to be the most
  • @HS-CNC (4.4 mol %) catalyst for the three-component coupling of formaldehyde, piperidine, and phenylacetylene (A3-coupling) under solvent-free conditions. Sketch illustrating preparation of the Au@HS-CNC catalyst. Three-component coupling of benzaldehyde, piperidine, and phenylacetylene catalyzed by
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Published 10 Jul 2013

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

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  • Laramie P. Jameson Sergei V. Dzyuba Department of Chemistry, Texas Christian University, Fort Worth, TX 76129, USA 10.3762/bjoc.9.89 Abstract BODIPY dyes have been synthesized under solvent-free or essentially solvent-free conditions, within about 5 minutes in an open-to-air setup by using a
  • at the meso-position (Scheme 4), using triethyl orthoformate as the aldehyde component. Similar to all other cases, the literature synthesis of this BODIPY dye was performed in solution and required several hours [15]. The synthesis could be accomplished under solvent-free conditions within 5 minutes
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Published 23 Apr 2013
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