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Search for "enamide" in Full Text gives 36 result(s) in Beilstein Journal of Organic Chemistry.

The Flögel-three-component reaction with dicarboxylic acids – an approach to bis(β-alkoxy-β-ketoenamides) for the synthesis of complex pyridine and pyrimidine derivatives

  • Mrinal K. Bera,
  • Moisés Domínguez,
  • Paul Hommes and
  • Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 394–404, doi:10.3762/bjoc.10.37

Graphical Abstract
  • account (six new bonds are formed for each product) and considering possible (unknown) side reactions these yields are quite satisfactory. In analogy to our previously published results [38][51][52] the double bond geometry of the enamide moiety is likely to be E-configured as shown in Scheme 2, allowing
  • E- and Z-configured enamide moieties [51][52], finally leading to identical products. After these successful multicomponent reactions we investigated the intramolecular condensations of the bis(β-ketoenamides) 13–15 to pyridine and pyrimidine derivatives. Enamides 13 and 14 were treated with
  • cyclocondensation of bis(β-ketoenamides) 13–15 to pyrimidines (Scheme 4) using ammonium acetate as ammonia source. Initially we subjected enamide 13 to conditions that had been optimized for mono-β-ketoenamides [48][49], in this case resulting in incomplete conversion: after heating 13 with 8 equiv of ammonium
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Published 13 Feb 2014

Total synthesis of (+)-grandiamide D, dasyclamide and gigantamide A from a Baylis–Hillman adduct: A unified biomimetic approach

  • Andivelu Ilangovan and
  • Shanmugasundar Saravanakumar

Beilstein J. Org. Chem. 2014, 10, 127–133, doi:10.3762/bjoc.10.9

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  • start with the same for the synthesis of dasyclamide (6). As explained in Scheme 5 attempts to get enamide 22 by reductive dehydroxylation of compound (±)-18 using NaBH4/CuCl2·2H2O or Al-NiCl2·2H2O [16][17][18] and reductive deacetoxylation of compound (±)-21 using NaBH4/t-BuOH or LiBEt3H, THF [19][20
  • ester 24 was hydrolyzed with aqueous KOH in methanol at room temperature to get acid 25 which was then treated with N-(4-aminobutyl)cinnamamide (11) in the presence of EDCI to get enamide 26. Further, deprotection was carried out with TFA to obtain dasyclamide (6) in an overall yield of 9.2% (Scheme 6
  • )-4-((4-methoxybenzyl)oxy)-2-methylbut-2-enamide (22). Synthesis of dasyclamide. Synthesis of gigantamide A (7) by oxidation of dasyclamide (6). Supporting Information Supporting Information File 52: Detailed experimental procedures, copies of 1H and 13C NMR spectra for the new compounds and chiral
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Published 10 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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  • iodine is a mild catalyst with moderate Lewis acidity. Thus, a possible mechanism was proposed in Scheme 1. The first step is the condensation via the primary nitrogen of mono-substituted urea 1 with the aromatic aldehyde 3 to give the intermediate 5. Then, the enamide 6 is generated through the
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Published 11 Dec 2013

One-pot cross-enyne metathesis (CEYM)–Diels–Alder reaction of gem-difluoropropargylic alkynes

  • Santos Fustero,
  • Paula Bello,
  • Javier Miró,
  • María Sánchez-Roselló,
  • Günter Haufe and
  • Carlos del Pozo

Beilstein J. Org. Chem. 2013, 9, 2688–2695, doi:10.3762/bjoc.9.305

Graphical Abstract
  • reaction mixture was purified by flash chromatography in hexanes/ethyl acetate (3:1). N-Benzyl-2,2-difluoro-3-methylenepent-4-enamide (2a). Following the procedure described above and before adding the dienophile, the crude mixture was subjected to flash chromatography affording 41 mg of 2a (70% yield) as
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Published 28 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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  • ) resulting in the formation of enone 2.23, this material was subsequently condensed with enamide 2.22 to directly yield clevidipine (2.3, Route B, [71]). A final strategy is depicted in Scheme 26 (Route C, [72]). This approach is similar to route B, however, it introduces the amine as part of the readily
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Published 30 Oct 2013

Gold(I)-catalyzed enantioselective cycloaddition reactions

  • Fernando López and
  • José L. Mascareñas

Beilstein J. Org. Chem. 2013, 9, 2250–2264, doi:10.3762/bjoc.9.264

Graphical Abstract
  • investigations by the groups of Mascareñas, González and Chen revealed that the gold-catalyzed cycloaddition between an allenamide and an appropriate alkene (e.g., enamide, enol ether or vinylarene) provides a variety of cyclobutanic systems in excellent yields. The optimum catalysts for the racemic processes
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Published 30 Oct 2013

Regio- and stereoselective carbometallation reactions of N-alkynylamides and sulfonamides

  • Yury Minko,
  • Morgane Pasco,
  • Helena Chechik and
  • Ilan Marek

Beilstein J. Org. Chem. 2013, 9, 526–532, doi:10.3762/bjoc.9.57

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  • alkenes is the carbometallation reaction of alkynes [16][17][18], ynamide should be a suitable substrate for the regio- and stereoselective synthesis of enamide through carbometallation reaction [19][20][21][22]. Although the stereoselectivity of the carbocupration is usually controlled through a syn
  • primary and secondary alkylcopper species (still obtained in diethyl ether from 1.0 equiv of a Grignard reagent and 1.0 equiv of CuBr, conditions A) to give the corresponding vinylcopper intermediate 5. Simple hydrolysis led to the enamide 6a,c in good isolated yields after purification by column
  •  3. Our initial attempt was performed with organocopper species prepared from alkylmagnesium halide and CuBr (1:1 ratio) and ynamide 7a (R1 = Hex), which cleanly led to the enamide 9a in very good isolated yield for the addition of MeCu, and with excellent regioselectivities (α/β > 95:5, Table 3
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Published 13 Mar 2013

A practical two-step procedure for the preparation of enantiopure pyridines: Multicomponent reactions of alkoxyallenes, nitriles and carboxylic acids followed by a cyclocondensation reaction

  • Christian Eidamshaus,
  • Roopender Kumar,
  • Mrinal K. Bera and
  • Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2011, 7, 962–975, doi:10.3762/bjoc.7.108

Graphical Abstract
  • -thiophene carboxylic acid. The relatively low yield in the formation of 66 might be explained by the poor solubility of 2-picolinic acid in ethereal solvents rather than for reactivity reasons. In contrast to the other examples, enamide 66 was obtained as a 1:1 mixture of (E)- and (Z)-isomers. This may be
  • step. The results are depicted in Table 4. In all examples the cyclization/nonaflation sequence provided the pyrid-4-yl nonaflates in good yields. Apparently, the reactivity in this sequence is not strongly governed by the structure of the original ketoenamide. Even the configuration of the enamide
  • double bond seems to have no influence on the cyclization, since the (E/Z)-mixture of enamide 66 also gave the corresponding pyridine in good yield. Obviously, the diastereomers are in equilibrium under the cyclization conditions. Of particular interest are the pyrid-4-yl nonaflates 71 and 72, possessing
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Published 13 Jul 2011

Recent advances in the gold-catalyzed additions to C–C multiple bonds

  • He Huang,
  • Yu Zhou and
  • Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

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  • and mild synthesis of enamides (193–196) by a gold-catalyzed nucleophilic addition to allenamides 191 (Scheme 36) [87]. For example, treatment of allenamide and 1-methylindole with 5.0 mol % of PPh3AuNTf2 in CH2Cl2 at room temperature gave the corresponding enamide in 83% yield. Gold-catalyzed direct
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Published 04 Jul 2011

Isotopic labelling studies for a gold-catalysed skeletal rearrangement of alkynyl aziridines

  • Paul W. Davies,
  • Nicolas Martin and
  • Neil Spencer

Beilstein J. Org. Chem. 2011, 7, 839–846, doi:10.3762/bjoc.7.96

Graphical Abstract
  • benzylic cation I (Path III) or the enamide stabilised cation B (Path II), under a cationic ring-expansion manifold, is apparently closely balanced: Products from both pathways are observed for alkyl substituted systems such as 11 and 15. However, when the alkyne substituent is a phenyl group Path II is
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Published 21 Jun 2011

An efficient and practical entry to 2-amido-dienes and 3-amido-trienes from allenamides through stereoselective 1,3-hydrogen shifts

  • Ryuji Hayashi,
  • John B. Feltenberger,
  • Andrew G. Lohse,
  • Mary C. Walton and
  • Richard P. Hsung

Beilstein J. Org. Chem. 2011, 7, 410–420, doi:10.3762/bjoc.7.53

Graphical Abstract
  • the pro-E transition state (Scheme 4). A thermodynamically driven equilibration from (Z)- to (E)-enamide post-isomerization is a real possibility that cannot be ruled out, and the observed solvent effect on the (E/Z)-selectivity would particularly support this possible notion. An interesting discovery
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Published 07 Apr 2011
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