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Search for "diketones" in Full Text gives 129 result(s) in Beilstein Journal of Organic Chemistry.

Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations

  • Paul Hommes and
  • Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2016, 12, 1170–1177, doi:10.3762/bjoc.12.112

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  • Paul Hommes Hans-Ulrich Reissig Freie Universität Berlin, Institut für Chemie und Biochemie, Takustrasse 3, D-14195 Berlin, Germany 10.3762/bjoc.12.112 Abstract The scope of a flexible route to unsymmetrically functionalized bipyridines is described. Starting from 1,3-diketones 1a–e, the
  • we reported on a new pyridine synthesis starting from symmetrically substituted 1,3-diketones 1a and 1b, respectively, that were converted into the corresponding β-ketoenamines and subsequently by N-acylation into β-ketoenamides such as 3a or 3b [1]. Their cyclocondensation followed by O-alkylation
  • available in excellent yields from the 1,3-diketones 1a and 1b employing aqueous ammonia in the presence of silica gel [21]. Compound 2c was prepared from 1c in 87% yield with ammonium formate [22][23]. Interestingly, treatment of 1c with aqueous ammonia/silica gel failed to give 2c, deacetylation to 1
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Published 09 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

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  • -diketones. Reaction of nitrostyrenes with β-keto esters and β-dicarbonyl compounds. Reaction of nitrostyrenes with α-nitrocyclohexanone and ethyl α-nitropropionate. Screening of catalysts and optimization of the reaction conditions for the additions of diethyl malonate and ethyl 2-oxocyclopentanecarboxylate
  • to β-nitrostyrene. Addition of malonates and β-diketones to nitrostyrenes catalyzed by IV and V. Reaction of nitrostyrenes with β-substituted cycloalkanones catalyzed by V. Reactions of nitrostyrenes with α-nitrocyclohexanone and ethyl α-nitropropionate. Supporting Information Supporting Information
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Published 01 Apr 2016

C–H bond halogenation catalyzed or mediated by copper: an overview

  • Wenyan Hao and
  • Yunyun Liu

Beilstein J. Org. Chem. 2015, 11, 2132–2144, doi:10.3762/bjoc.11.230

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  • practical application of these metal-free methods. The application of copper catalysts was found as effective solution to some of these problems. For example, Wu et al. [70] reported the efficient synthesis of α-iodoketals 76 and 77 via CuO-mediated selective mono-iodination of diketones 74 and
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Published 09 Nov 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

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  • Abstract The reaction of α-azidochalcones with carboxylic acids has been investigated resulting in the formation of α-amido-1,3-diketones under microwave irradiation via in situ formation of 2H-azirine intermediates. An interesting reaction is described wherein, with trifluoroacetic acid at lower
  • 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
  • various substituted benzoic acids 2d–g as well and the resultant α-amido-1,3-diketones 3k–o are obtained in moderate to good yields (Figure 3). The mechanism for the formation of α-amido-1,3-diketone 3 is given in Scheme 2. Initially, by thermolysis, α-azidochalcone undergoes denitrogenative decomposition
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Published 29 Oct 2015

Design and synthesis of hybrid cyclophanes containing thiophene and indole units via Grignard reaction, Fischer indolization and ring-closing metathesis as key steps

  • Sambasivarao Kotha,
  • Ajay Kumar Chinnam and
  • Mukesh E. Shirbhate

Beilstein J. Org. Chem. 2015, 11, 1514–1519, doi:10.3762/bjoc.11.165

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  • explored the alternative option to the target cyclophane 1 involving the bisindolization followed by RCM (Figure 1, Route B). To design aza-polyquinanes, we reported several bisindole derivatives starting with diketones under conditions of a low melting reaction mixture [38][39][40]. Based on this insight
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Published 31 Aug 2015

An intramolecular C–N cross-coupling of β-enaminones: a simple and efficient way to precursors of some alkaloids of Galipea officinalis

  • Hana Doušová,
  • Radim Horák,
  • Zdeňka Růžičková and
  • Petr Šimůnek

Beilstein J. Org. Chem. 2015, 11, 884–892, doi:10.3762/bjoc.11.99

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  • the starting substrates A simple retrosynthesis of enaminones 3 leads to the corresponding β-diketones 4 accessible through Claisen condensation of 3-phenylpropionic ester 5 with the appropriate acetophenone 6 (Scheme 3). The synthesis of ester 5 was accomplished according to Scheme 4. The classic
  • -Diketones 4 were obtained using tert-butoxide or tert-pentoxide mediated Claisen condensation of esters 5 with the appropriate acetophenones 6a–d (Scheme 5, step c). The substitution pattern on compounds 6 was chosen so that the final products 1 are the precursors for the synthesis of galipinine, galipeine
  • -diketones 4 with ammonium surrogate (AcONH4 or NH4HCO3). The regioselectivity of the synthesis was checked by means of 2D 1H–13C HMBC (See Supporting Information File 1, page S69). The non-equivalence of NH2 protons together with the relatively high chemical shift of one resonance of the pair (δ ≈ 10 ppm
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Published 27 May 2015

Bis(vinylenedithio)tetrathiafulvalene analogues of BEDT-TTF

  • Erdal Ertas,
  • İlknur Demirtas and
  • Turan Ozturk

Beilstein J. Org. Chem. 2015, 11, 403–415, doi:10.3762/bjoc.11.46

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  • Gebze-Kocaeli, Turkey 10.3762/bjoc.11.46 Abstract This review aims to give an overview of the current status of our research on the synthesis of π-electron donor bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF, ET) analogues prepared from 1,8-diketones via a ring forming reaction. The new synthesized π
  • molecules, obtained from 1,8-diketone ring closure reactions, and coupling reactions, published by our group. Review BVDT-TTF analogues from 1,8-diketones Bis(vinylenedithio)tetrathiafulvalene (BVDT-TTF) 4 (R = Ph, 4-CH3OC6H4, 4-BrC6H4, 4-CH3C6H4, 4-O2NC6H4, 2-thienyl) is a fully unsaturated analogue of
  • produce 13 as a minor product through the intermediate 12 by the loss of elemental sulfur. The reaction of a series of 1,8-diketones with LR 15 or P4S10 was further explored in 2003 [53]. With both reactants, 1,4-dithiin 11 was obtained as a major and thiophene 13 as a minor product along with the side
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Published 27 Mar 2015

Azirinium ylides from α-diazoketones and 2H-azirines on the route to 2H-1,4-oxazines: three-membered ring opening vs 1,5-cyclization

  • Nikolai V. Rostovskii,
  • Mikhail S. Novikov,
  • Alexander F. Khlebnikov,
  • Galina L. Starova and
  • Margarita S. Avdontseva

Beilstein J. Org. Chem. 2015, 11, 302–312, doi:10.3762/bjoc.11.35

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  • 5-acyl-substituted 2H-1,4-oxazines. They could, in principle, be prepared from azirines and α-diazo ketones or 2-diazo-1,3-diketones via ring opening across the N–C2 bond in the intermediate azirinium ylides to form 2-azabuta-1,3-dienes and subsequent cyclization of the latter into 2H-1,4-oxazines
  • the mechanism of trapping of dihydroazireno[2,1-b]oxazole intermediates by acetyl(methyl)ketene were investigated by the DFT method. Results and Discussion Rhodium(II) carbenoids generated from α-diazoketones or 2-diazo-1,3-diketones react with various nitrogen-containing compounds, such as amines [16
  • generated by thermolysis of 2-diazo-1,3-diketones [12] or 5-arylfuran-2,3-diones [13]. Therefore, the presence of compounds 8f,g among the reaction products provides evidence for the formation of some amounts of acetyl(methyl)ketene (12) under the reaction conditions, which, in turn, gives us insight to the
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Published 02 Mar 2015

The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde

  • Volodymyr V. Tkachenko,
  • Elena A. Muravyova,
  • Sergey M. Desenko,
  • Oleg V. Shishkin,
  • Svetlana V. Shishkina,
  • Dmytro O. Sysoiev,
  • Thomas J. J. Müller and
  • Valentin A. Chebanov

Beilstein J. Org. Chem. 2014, 10, 3019–3030, doi:10.3762/bjoc.10.320

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  • of the compounds 4–6a through the intermediate 7 (pathway A) as for cyclic 1,3-diketones [13][25] was excluded because the latter does not react with amide 3a under any comparable conditions. Most likely the formation of chroman-3-carboxamide 4a proceeds through imine 8 (pathway B) since the reaction
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Published 17 Dec 2014

(CF3CO)2O/CF3SO3H-mediated synthesis of 1,3-diketones from carboxylic acids and aromatic ketones

  • JungKeun Kim,
  • Elvira Shokova,
  • Victor Tafeenko and
  • Vladimir Kovalev

Beilstein J. Org. Chem. 2014, 10, 2270–2278, doi:10.3762/bjoc.10.236

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  • application of the proposed protocol allowed for the synthesis of selected polysubstituted pyrazoles in a one-pot procedure directly from acids and ketones. Keywords: Claisen condensation; 1,3-diketones; heterocycles; triflic acid; trifluoroacetic acid anhydride; Introduction 1,3-Diketones represent one of
  • synthesis of β-diketones from acids and ketones with an immediate activation of both carbonyl and methylene components in the course of the reaction. Herein, we would like to describe a direct and operationally simple TFAA/TfOH-mediated synthesis of 1,3-diketones from unmodified carboxylic acids and ketones
  • (indanones, tetralone, acetophenones, 2-acetylthiophene and methyl benzyl ketone) with alkanoic acids RCOOH 1d–h (where R = 1-adamantylmethyl, neopentyl, isopropyl, methyl, phenyl) gave the corresponding β-diketones 3c–t in 37–86% yields (Table 2). In most cases reactions were carried out at the molar ratios
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Published 26 Sep 2014

Derivatives of the triaminoguanidinium ion, 3. Multiple N-functionalization of the triaminoguanidinium ion with isocyanates and isothiocyanates

  • Jan Szabo,
  • Kerstin Karger,
  • Nicolas Bucher and
  • Gerhard Maas

Beilstein J. Org. Chem. 2014, 10, 2255–2262, doi:10.3762/bjoc.10.234

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  • 1,3-diketones follow condensation/cyclization pathways resulting in unsymmetrical N-heterocyclic products [14][15]. Azidation of TAG-Cl with two equivalents of sodium nitrite in water afforded the highly shock- and friction-sensitive (5-azido-1H-tetrazol-1-yl)carbonimidoyl diazide rather than the
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Published 24 Sep 2014

Chiral phosphines in nucleophilic organocatalysis

  • Yumei Xiao,
  • Zhanhu Sun,
  • Hongchao Guo and
  • Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218

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  • excellent ee (up to 96%). In subsequent transformations, the β-lactone products underwent various ring opening reactions to provide very useful derivatives, such as 1,3-diketones and enol esters, with good diastereoselectivity. 2.12 Annulations through domino aza-MBH/Michael reactions Because
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Published 04 Sep 2014

Five-membered ring annelation in [2.2]paracyclophanes by aldol condensation

  • Henning Hopf,
  • Swaminathan Vijay Narayanan and
  • Peter G. Jones

Beilstein J. Org. Chem. 2014, 10, 2021–2026, doi:10.3762/bjoc.10.210

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  • , and also furnishes three dehydration products, the anti-configurated diketones 21–23, produced in a 1:3:1 ratio. Again the fully or partially conjugated isomers are deeply colored (intense yellow) and display absorption maxima at 389 and 358 nm, respectively (Scheme 6). For 21 yellow single crystals
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Published 28 Aug 2014

A tandem Mannich addition–palladium catalyzed ring-closing route toward 4-substituted-3(2H)-furanones

  • Jubi John,
  • Eliza Târcoveanu,
  • Peter G. Jones and
  • Henning Hopf

Beilstein J. Org. Chem. 2014, 10, 1462–1470, doi:10.3762/bjoc.10.150

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  • [19][20][21][22][23][24][25][26]. Synthetic routes for the preparation of these compounds involve transformations of substituted α-hydroxy-1,3-diketones [15][17], substituted furans [27][28][29], cyclization of allenic hydroxyketones [30], transition metal-catalyzed strategies (Au [31][32][33], Pt [34
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Published 27 Jun 2014

Visible-light photoredox catalysis enabled bromination of phenols and alkenes

  • Yating Zhao,
  • Zhe Li,
  • Chao Yang,
  • Run Lin and
  • Wujiong Xia

Beilstein J. Org. Chem. 2014, 10, 622–627, doi:10.3762/bjoc.10.53

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  • the reaction, and the results are summarized in Scheme 3. The 1,2-dibromo products were obtained in moderate to high yields. With the success of the bromination of phenols and alkenes, we further focused on the complementary bromination of diketones and cyclization reactions. The treatment of
  • (monitored by TLC). After the reaction was completed, the solvent was concentrated in vacuo. The residue was purified by flash column chromatography to give the final product. Bromination of diketones To a 10 mL round bottom flask equipped with a magnetic stir bar were added 5 (0.4 mmol), CBr4 (133 mg, 0.4
  • situ generation of bromine. Synthesis of dibromophenol product 2b''. Scope of the photocatalytic bromination of alkenes. Bromination of diketones and cyclization reactions. Survey of the photocatalytic bromination reaction conditions. Scope of the photocatalytic bromination of phenols. Supporting
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Published 07 Mar 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

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  • several substituents and enolates 33 can be generated from methyl- or ethyl vinyl ketone, the corresponding α,β-unsaturated esters being unreactive. Enamines 34 arise from cyclic or linear C3–C5 ketones, acetophenones and β-diketones. It is noteworthy, that the reactions are highly regiospecific for
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Published 26 Feb 2014

Secondary amine-initiated three-component synthesis of 3,4-dihydropyrimidinones and thiones involving alkynes, aldehydes and thiourea/urea

  • Jie-Ping Wan,
  • Yunfang Lin,
  • Kaikai Hu and
  • Yunyun Liu

Beilstein J. Org. Chem. 2014, 10, 287–292, doi:10.3762/bjoc.10.25

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  • ) [14] has been dominantly employed for DHPMs synthesis in both racemic [15][16][17][18] and asymmetric versions [19][20][21][22][23]. Despite of many recognized advantages of the Biginelli reaction, the product diversity suffered from limitations because β-ketoesters or 1,3-diketones are intrinsically
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Published 29 Jan 2014

Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

  • Alexander O. Terent'ev,
  • Dmitry A. Borisov,
  • Vera A. Vil’ and
  • Valery M. Dembitsky

Beilstein J. Org. Chem. 2014, 10, 34–114, doi:10.3762/bjoc.10.6

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  • Kobayashi cyclization of hydroperoxides, the reaction of 1,4-diketones with hydrogen peroxide, the intramolecular nucleophilic substitution by the hydroperoxide group, the cyclization with participation of halogenonium ion donors, acid-mediated rearrangements of peroxides, the palladium-catalyzed
  • NaBH4 in an alkaline medium [331]. 3.6. Synthesis of 1,2-dioxanes from 1,4-dicarbonyl compounds The reaction of 1,4-diketones 242 (cyclohexanone derivatives) with hydrogen peroxide in a neutral medium produced 3,6-dihydroxydioxanes 243 albeit without reported yields (Scheme 69). The resulting compounds
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Published 08 Jan 2014

Efficient synthesis of dihydropyrimidinones via a three-component Biginelli-type reaction of urea, alkylaldehyde and arylaldehyde

  • Haijun Qu,
  • Xuejian Li,
  • Fan Mo and
  • Xufeng Lin

Beilstein J. Org. Chem. 2013, 9, 2846–2851, doi:10.3762/bjoc.9.320

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  • chemistry [5][6][7][8]. Recently, many one-pot variants of Biginelli-type reactions for the preparation of novel DHPMs using various active methylene compounds [9][10][11][12][13][14][15], such as enaminone, cyclic β-diketones, acetophenone, benzocyclic ketones and β-oxodithioesters etc., have also been
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Published 11 Dec 2013

Novel supramolecular affinity materials based on (−)-isosteviol as molecular templates

  • Christina Lohoelter,
  • Malte Brutschy,
  • Daniel Lubczyk and
  • Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2013, 9, 2821–2833, doi:10.3762/bjoc.9.317

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  • al. [61]. Further, (−)-isosteviol and its esters can be converted into the corresponding 1,2-diketones 5a–c via Riley oxidation [62][63][64][65][66]. The linkage of the two building blocks by condensation reaction of the keto with the amino functionalities presents a promising route for the
  • %. Since path A and path B both proceed with almost identical yields, either pathway is suitable for the preparation of such protected 1,2-diketones. Apart from applying 3,5-dinitrobenzyl chloride in the reaction sequence, the conversion of the carboxylic acids 1 and 9 with 4-nitrobenzyl (PNB) chloride was
  • overall yields as well, rendering 11 in 54% and 57%, respectively. Upon employing 4-nitrobenzyl chloride, both reaction paths result in slightly higher yields than the analogous reactions with 3,5-dinitrobenzyl chloride. Diketones 10 and 11 were then brought to condensation with hexaammoniumtriptycene
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Published 09 Dec 2013

New developments in gold-catalyzed manipulation of inactivated alkenes

  • Michel Chiarucci and
  • Marco Bandini

Beilstein J. Org. Chem. 2013, 9, 2586–2614, doi:10.3762/bjoc.9.294

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  • . 4.1 Alkylation of active methylene compounds Hydroalkylation of styrenes, indene and norbornene with 1,3-diketones was firstly reported in 2004 by using AuCl3 and AgOTf in 1:3 ratio as the catalyst (Scheme 15) [51]. The addition took place with Markovnikov selectivity in good yields, however optimal
  • conditions suffered from severe limitations on 1,3-diketones as nucleophiles and unfunctionalized olefins. The same catalytic system was then employed with cyclic enols, dienes and trienes although lower yields were recorded [52]. Remarkably, the intramolecular [Au(I)]-catalyzed addition of β-keto amides to
  • . Mechanistic proposal for the cooperative [Au(I)]/menthol catalysis for the enantioselective intramolecular hydroamination of dienes. [Au(III)]-catalyzed addition of 1,3-diketones to alkenes. [Au(I)]-catalyzed intramolecular addition of β-keto amides to alkenes. Intermolecular [Au(I)]-catalyzed addition of
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Published 21 Nov 2013

Ambient gold-catalyzed O-vinylation of cyclic 1,3-diketone: A vinyl ether synthesis

  • Yumeng Xi,
  • Boliang Dong and
  • Xiaodong Shi

Beilstein J. Org. Chem. 2013, 9, 2537–2543, doi:10.3762/bjoc.9.288

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  • Yumeng Xi Boliang Dong Xiaodong Shi C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States 10.3762/bjoc.9.288 Abstract Gold-catalyzed O-vinylation of cyclic 1,3-diketones has been achieved for the first time, which provides direct
  • 1,3-diketones with unactivated alkynes at ambient temperature. Results and Discussion As indicated in Scheme 1, the main challenge for the intermolecular O-nucleophile addition to alkynes is the competitive hydration side reaction. Although, theoretically, strictly anhydrous conditions shall prevent
  • , though in low yield. Two regioisomers were isolated, which were assigned as 8a and 8b (Scheme 3A). Diphenylacetylene gave trace amounts of the desired product under the identical conditions. Several diketones were tested to explore the scope of nucleophiles. The 1,3-cyclohexanedione derivative worked
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Published 18 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
  • attention of synthetic as well as medicinal chemists [7][8][9]. Various methodologies for the synthesis of isocoumarins have been reported such as the reaction of o-halobenzoic acids and 1,3-diketones through a copper-catalyzed tandem sequential cyclization/addition/deacylation process [10][11], an iridium
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Published 04 Nov 2013

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

  • Marcus Baumann and
  • Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

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Published 30 Oct 2013

Mechanistic studies on the CAN-mediated intramolecular cyclization of δ-aryl-β-dicarbonyl compounds

  • Brian M. Casey,
  • Dhandapani V. Sadasivam and
  • Robert A. Flowers II

Beilstein J. Org. Chem. 2013, 9, 1472–1479, doi:10.3762/bjoc.9.167

Graphical Abstract
  • 73% yield. To examine the breadth of this method, a series of δ-aryl-β-dicarbonyl substrates was prepared by a previously reported procedure [17]. As shown in Table 1, the intramolecular cyclization of δ-aryl-β-diketones with unsubstituted aryl rings (Table 1, entries 1 and 3) afforded 2-tetralone
  • oxidation of several β-diketones and their related silyl enol ethers by CAN and the more lipophilic ceric tetra-n-butylammonium nitrate (CTAN) were measured in MeOH, MeCN and CH2Cl2 by using stopped-flow spectrophotometry [16]. In these experiments, initial oxidation of substrates generated radical cation
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Published 23 Jul 2013
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