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Search for "hetero-Diels–Alder" in Full Text gives 43 result(s) in Beilstein Journal of Organic Chemistry.

Aza-Diels–Alder reaction between N-aryl-1-oxo-1H-isoindolium ions and tert-enamides: Steric effects on reaction outcome

  • Amitabh Jha,
  • Ting-Yi Chou,
  • Zainab ALJaroudi,
  • Bobby D. Ellis and
  • T. Stanley Cameron

Beilstein J. Org. Chem. 2014, 10, 848–857, doi:10.3762/bjoc.10.81

Graphical Abstract
  • isoindolo[2,1-a]quinolone derivatives involves N-acyliminium ions or appropriate electron-deficient Schiff bases and subsequent [4 + 2] inverse-demand hetero-DielsAlder cycloadditions with alkenes [11][12][13][14][15][16][17]. Vinylic systems from isoeugenol [11], cyclopentadiene [12], enones [13], vinyl
  • (series 1 and 2) from 1-oxo-2-aryl-1H-isoindolium ions (A) and appropriate tert-enamides (Scheme 1). Although this is the first report of the use of tert-enamides as a dienophile for the hetero-DielsAlder reaction with N-acyliminium cations, formation of isoindoloquinolines (series 1 and 2) was rather
  • the dienophile, at least two regioisomers can be visualized for these compounds. Based on our characterization results, only one regioisomer, where the substitution was at position 5 of the isoindoloquinoline ring, was exclusively formed in these reactions. Inverse-electron demand hetero-DielsAlder
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Published 14 Apr 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
  • -type reactions, hetero DielsAlder reactions, 1,3-dipolar cycloadditions and nitroso aldol reactions [93]. The process was firstly accomplished with preformed aryl-substituted aldimines [94] and then developed as a MCR for less stable alkyl-substituted aldimines, which were prepared in situ from
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Published 26 Feb 2014

Boron-substituted 1,3-dienes and heterodienes as key elements in multicomponent processes

  • Ludovic Eberlin,
  • Fabien Tripoteau,
  • François Carreaux,
  • Andrew Whiting and
  • Bertrand Carboni

Beilstein J. Org. Chem. 2014, 10, 237–250, doi:10.3762/bjoc.10.19

Graphical Abstract
  • methodology [62][63][64]. The combination of the catalytic hetero-DielsAlder/allyboration sequence with a ruthenium-catalyzed isomerization gave access to the 6,8-dioxabicyclo[3.2.1]octane skeleton of (+)-iso-exo-brevicomin (26, Scheme 18) [65]. When a Z/E mixture of 2-substituted enol ethers was used as
  • of each 1,3-dienyl system, sequential hetero-DielsAlder/Diels–Alder reactions (or vice versa if the order of introduction of the reagents was inversed) were carried out chemoselectively. The allylboronic ester moiety, generated in the first cycloaddition step or after the two consecutive [4 + 2
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Published 22 Jan 2014

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

  • Sebastian Krüger and
  • Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

Graphical Abstract
  • was achieved using TBAF, followed by formation of a vinyl triflate and Stille coupling with tributyltin hydride. The oxidation state of the remaining ester was adjusted to the corresponding aldehyde, followed by a Lewis acid-catalyzed intramolecular inverse-electron-demand hetero-DielsAlder reaction
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Published 16 Jan 2014

Stereodivergent synthesis of jaspine B and its isomers using a carbohydrate-derived alkoxyallene as C3-building block

  • Volker M. Schmiedel,
  • Stefano Stefani and
  • Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2013, 9, 2564–2569, doi:10.3762/bjoc.9.291

Graphical Abstract
  • auxiliaries for the synthesis of enantiopure natural products such as preussin [39] and anisomycin [40] or in hetero DielsAlder reactions [41][42]. For the stereodivergent synthesis of both enantiomers of jaspine B (1), we chose diacetoneglucose-derived alkoxyallene 11, which is easily accessible on gram
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Published 19 Nov 2013

Diastereoselective synthesis of nitroso acetals from (S,E)-γ-aminated nitroalkenes via multicomponent [4 + 2]/[3 + 2] cycloadditions promoted by LiCl or LiClO4

  • Leandro Lara de Carvalho,
  • Robert Alan Burrow and
  • Vera Lúcia Patrocinio Pereira

Beilstein J. Org. Chem. 2013, 9, 838–845, doi:10.3762/bjoc.9.96

Graphical Abstract
  • diffraction experiment. Keywords: chiral heterodiene; hetero-DielsAlder reaction; pyrrolizidin-3-one; solvent effect; tandem reaction; Introduction Conjugated nitroalkenes play an important role in cycloaddition reactions providing useful nitrogenated cycloadducts with varied synthetic applications (Scheme
  • furnish cyclic nitronate derivatives of type 3 [1][3]. In particular, the reactivity of nitroalkenes with unactivated olefins has been extensively investigated by Denmark and co-workers in [4 + 2] hetero-DielsAlder (HDA) cycloadditions [1][3] and, in some instances, the resulting cyclic nitronates such
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Published 30 Apr 2013

A versatile and efficient approach for the synthesis of chiral 1,3-nitroamines and 1,3-diamines via conjugate addition to new (S,E)-γ-aminated nitroalkenes derived from L-α-amino acids

  • Vera Lúcia Patrocinio Pereira,
  • André Luiz da Silva Moura,
  • Daniel Pais Pires Vieira,
  • Leandro Lara de Carvalho,
  • Eliz Regina Bueno Torres and
  • Jeronimo da Silva Costa

Beilstein J. Org. Chem. 2013, 9, 832–837, doi:10.3762/bjoc.9.95

Graphical Abstract
  • hetero-DielsAlder reactions [27][28][29][30][31] and even participate in cross-coupling reactions [32]. Due to this notable reactivity, obtaining new chiral and achiral nitroalkenes is of great importance in synthetic organic chemistry. Achiral nitroalkenes, specifically the chemically stable β-trans
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Published 30 Apr 2013

Facile synthesis of functionalized tetrahydroquinolines via domino Povarov reactions of arylamines, methyl propiolate and aromatic aldehydes

  • Jing Sun,
  • Hong Gao,
  • Qun Wu and
  • Chao-Guo Yan

Beilstein J. Org. Chem. 2012, 8, 1839–1843, doi:10.3762/bjoc.8.211

Graphical Abstract
  • reaction; tetrahydroquinoline; Introduction The Diels–Alder reaction is recognized as a powerful reaction in synthetic strategies for the production of natural and unnatural polycarbocycles and polyheterocycles [1][2][3]. Therefore, the hetero-DielsAlder reactions and domino reaction procedures have been
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Published 26 Oct 2012

Asymmetric Brønsted acid-catalyzed aza-Diels–Alder reaction of cyclic C-acylimines with cyclopentadiene

  • Magnus Rueping and
  • Sadiya Raja

Beilstein J. Org. Chem. 2012, 8, 1819–1824, doi:10.3762/bjoc.8.208

Graphical Abstract
  • -DielsAlder reaction. From the different catalysts tested, phosphoric acid diester 4b, with the 2,4,6-triisopropylphenyl substituent in the 3,3’-position of the BINOL backbone, proved to be the best catalyst, and the product was obtained with an encouraging enantiomeric excess of 74% (Table 1, entry 3
  • when the reaction was performed in toluene at −60 °C in the presence of catalyst 4a (Table 1, entry 1). A slight increase in enantioselectivity was observed when the reaction was conducted at −78 °C (Table 1, entry 2). Subsequently, different catalysts were applied in the Brønsted acid catalyzed hetero
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Published 23 Oct 2012

Synthesis and antifungal properties of papulacandin derivatives

  • Marjolein van der Kaaden,
  • Eefjan Breukink and
  • Roland J. Pieters

Beilstein J. Org. Chem. 2012, 8, 732–737, doi:10.3762/bjoc.8.82

Graphical Abstract
  • two different research groups [30][31][32][33] and additionally a number of different synthetic routes [34][35][36][37][38] to the spiroketal core structure have been published, including a hetero DielsAlder reaction [39], a palladium(0)-catalyzed coupling [40][41][42][43][44][45] and a condensation
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Published 14 May 2012

Alkoxide-induced ring opening of bicyclic 2-vinylcyclobutanones: A convenient synthesis of 2-vinyl-substituted 3-cycloalkene-1-carboxylic acid esters

  • Xiufang Ji,
  • Zhiming Li,
  • Quanrui Wang and
  • Andreas Goeke

Beilstein J. Org. Chem. 2012, 8, 650–657, doi:10.3762/bjoc.8.72

Graphical Abstract
  • proceeds by a two-step process, involving an initial hetero DielsAlder cycloaddition of the diene and the ketene carbonyl group, followed by a [3,3]-sigmatropic (Claisen) rearrangement [25][26]. The most effective conditions were achieved by the employment of a slightly excessive amount of olefins 1. The
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Published 26 Apr 2012
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  • efficient preparation include Prins cyclizations, intramolecular substitutions, ring closure metathesis, and hetero DielsAlder reactions [1][2]. Our group recently reported the synthesis of enantiopure aminopyrans employing as the key step a Lewis acid induced rearrangement of 1,2-oxazines to bicyclic
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Published 09 Jul 2010
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  • DielsAlder reactions involving 1-oxa-1,3-butadienes. Keywords: β-halo aldehydes; hetero DielsAlder reaction; 1-oxa-1,3-butadiene; pyrido[2,3-d]pyrimidines; uracil; Introduction The importance of uracil and its annulated derivatives is well recognized by synthetic as well as biological chemists [1][2
  • preparation of these complex molecules. However, there still remains many challenges in the synthesis of these naturally occurring complex molecules [22][23][24][25][26][27][28][29][30][31]. Hetero DielsAlder reactions [32][33][34][35] are becoming a mainstay of heterocyclic and natural product synthesis
  • complex annulated pyrido[2,3-d]pyrimidines by intramolecular hetero DielsAlder reactions involving 1-oxa-1,3-butadienes (Scheme 1). The key intermediate, the 2-chloro-3-formyl uracil derivative 1 (β-halo aldehyde), was prepared by the reaction of N,N-dimethyl barbituric acid with Vielsmeier reagent (DMF
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Published 04 Feb 2010

Palladium- catalyzed cross coupling reactions of 4-bromo- 6H-1,2-oxazines

  • Reinhold Zimmer,
  • Elmar Schmidt,
  • Michal Andrä,
  • Marcel-Antoine Duhs,
  • Igor Linder and
  • Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2009, 5, No. 44, doi:10.3762/bjoc.5.44

Graphical Abstract
  • literature describes just one related 4-chloro-substituted 6H-1,2-oxazine which was prepared by a hetero-DielsAlder cycloaddition–elimination sequence of 2-chloro-1-nitroso-1-phenyl-ethene and 1-bromo-2-ethoxyethene in low yield (22%) [32]. As demonstrated in Scheme 2, a more efficient approach consists in
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Preliminary Communication
Published 16 Sep 2009

Mitomycins syntheses: a recent update

  • Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

Graphical Abstract
  • introduction of the N-methyl aziridine in only three steps from an olefin by cycloaddition of methylthiophenyl azide onto the unsaturated amide 29. As mentioned before, the construction of FR-900482 was thought to occur by intramolecular hetero DielsAlder reaction of a compound of type 32 (Scheme 8) [51
  • ]. After careful analysis, it was envisioned that the reaction could occur either in the bridged mode to give the FR series (compounds 3 and 4) or in the fused mode to give access to mitomycins. Further investigations confirmed that the intramolecular hetero DielsAlder reaction favoured the fused mode and
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Published 08 Jul 2009

Recent progress on the total synthesis of acetogenins from Annonaceae

  • Nianguang Li,
  • Zhihao Shi,
  • Yuping Tang,
  • Jianwei Chen and
  • Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

Graphical Abstract
  • THF unit 140 was then constructed by ozonolysis of the alkenol 137 to give the lactol 138. Treatment of 138 with an excess of propargyl alcohol afforded 139, which was followed by anomeric O-C rearrangement to give 140. The hetero-Diels-Alder (HDA) reaction between diene 141 and nitrosobenzene
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Published 05 Dec 2008

An efficient synthesis of novel pyrano[2,3-d]- and furopyrano[2,3-d]pyrimidines via indium- catalyzed multi- component domino reaction

  • Dipak Prajapati and
  • Mukut Gohain

Beilstein J. Org. Chem. 2006, 2, No. 11, doi:10.1186/1860-5397-2-11

Graphical Abstract
  • Knoevenagel/hetero-Diels-Alder reaction of 1,3-dimethyl barbituric acid with an aromatic aldehyde and ethyl vinyl ether/2,3-dihydrofuran in presence of 1 mol% of indium(III) chloride. The reaction also proceeds in aqueous media without using any catalyst, but the yield is comparatively less (65–70
  • Mukaiyama Aldol reactions, Friedel-Crafts acylations,[6] Pavarob reactions[7] and Diels-Alder reactions[8] in water. Since the work of Loh,[8] indium halide has also been shown to be an effective Lewis acid catalyst for various reactions in aqueous media. [9][10] However, its use in the hetero Diels-Alder
  • reaction of α,β-ethylenic ketones and ethyl vinyl ether or 2,3-dihydrofuran has remained unexplored.[11] Herein, we report the first example of indium(III) chloride catalysed synthesis of fused pyrimidine derivatives via a multicomponent domino Knoevenagel hetero Diels-Alder reaction. The reaction proceeds
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Published 13 Jun 2006

Synthesis of 2,6-trans- disubstituted 5,6-dihydropyrans from (Z)-1,5-syn-endiols

  • Eric M. Flamme and
  • William R. Roush

Beilstein J. Org. Chem. 2005, 1, No. 7, doi:10.1186/1860-5397-1-7

Graphical Abstract
  • dihydropyrans are common structural elements of many biologically active natural products.[2][3] A number of methods have been developed to synthesize substituted dihydropyrans including: (i) hetero-Diels-Alder cycloadditions,[4][5][6][7] (ii) electrophile-initiated alkylation of glycals,[8][9][10][11] (iii
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Published 26 Aug 2005
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