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

Metal-free hydroarylation of the side chain carbon–carbon double bond of 5-(2-arylethenyl)-3-aryl-1,2,4-oxadiazoles in triflic acid

  • Anna S. Zalivatskaya,
  • Dmitry S. Ryabukhin,
  • Marina V. Tarasenko,
  • Alexander Yu. Ivanov,
  • Irina A. Boyarskaya,
  • Elena V. Grinenko,
  • Ludmila V. Osetrova,
  • Eugeniy R. Kofanov and
  • Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2017, 13, 883–894, doi:10.3762/bjoc.13.89

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  • investigation of their properties are of ongoing interest in chemistry and medicine. Based on our previous works on reactions of cinnamides [24] and 5-styryl-2H-tetrazoles [25] with arenes under superelectrophilic activation with Brønsted or Lewis superacids, we turned our attention towards the hydroarylation
  • our recent study on the hydroarylation of styryl tetrazoles [25]. Indeed, under MW activation the reactions in TfOH proceeded within 5–20 min at 120 °C (Table 3, entries 4–9) with formation of oxadiazoles 2 in high yields (compare the yields under thermal and MW heating in Table 3). The MW-activated
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Published 11 May 2017

Robust C–C bonded porous networks with chemically designed functionalities for improved CO2 capture from flue gas

  • Damien Thirion,
  • Joo S. Lee,
  • Ercan Özdemir and
  • Cafer T. Yavuz

Beilstein J. Org. Chem. 2016, 12, 2274–2279, doi:10.3762/bjoc.12.220

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  • acids, tetrazoles, amines or amidoximes [14][15][16][17]. To the best of our knowledge the nitrile functionality has not been explored in other types of porous polymers, except our earlier work [18]. Herein we report the synthesis of two new cyanovinylene-bridged covalent organic polymers, indexed as
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Letter
Published 28 Oct 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
  • bonds, such as carboxylic acids, tetrazoles, thioureas, etc. The selectivity observed, when steric shielding interaction is employed, is due to the bulky group of the catalyst. This group shields one face of the enamine to provide the selectivity. The third most valuable and studied mode of activation
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Published 10 Mar 2016

Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

  • Katherine M. Byrd

Beilstein J. Org. Chem. 2015, 11, 530–562, doi:10.3762/bjoc.11.60

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  • studies as the basis for the development of the 1,4-addition of N-heterocycles to α,β-unsaturated imides. They applied both substituted and unsubstituted purines, benzotriazole, and 5-substituted tetrazoles as nucleophiles to this reaction, which resulted in moderate to excellent yields and excellent
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Published 23 Apr 2015

Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics

  • Gijs Koopmanschap,
  • Eelco Ruijter and
  • Romano V.A. Orru

Beilstein J. Org. Chem. 2014, 10, 544–598, doi:10.3762/bjoc.10.50

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  • ease of preparation via IMCRs [27][28][29]. First, the β-lactams will be described followed by five-membered rings varying from pyrrolidines to tetrazoles based amide bond isosteres. Examples of the six-membered rings showing peptide like-properties are the piperazines, homoprolines, dihydropyrimidones
  • deprotected and cyclized the linear products towards the oxazole derivatives 146 in yields up to 73%. Tetrazoles In medicinal chemistry, tetrazoles are often used as carboxylic acid bio-isosteres due to their comparable acidity [114]. However, studies towards 1,5-disubstituted tetrazoles have shown that these
  • approach and resulted in a library of tetrazoles 150 with excellent yields and high enantiomeric excesses (51–97%). For this enantioselectivity, the authors proposed a mechanism as shown in Scheme 46. In addition, from their study it became clear that the azide moiety is directly transferred from HN3 and
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Published 04 Mar 2014
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  • tetrazoles 23 and 24 are collected in Table 1. The formation of different mixtures of the three cyanodimethylpyrroles 25–27 depending on the conditions can be explained in terms of chemical activation. The formation of (hetero)arylcarbenes and their rearrangement to (hetero)arylnitrenes and cyanopyrroles are
  • is required for this, whereas 400 °C suffices in the FVT of the tetrazoles (Table 1). Following the analysis of the ring contraction in 3-pyridylnitrene (10) by ring expansion and ring opening to a nitrile ylide (Scheme 4 and Figure 1), we can interpret the reactions in terms of ring expansion of the
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Published 17 Apr 2013

Some aspects of radical chemistry in the assembly of complex molecular architectures

  • Béatrice Quiclet-Sire and
  • Samir Z. Zard

Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61

Graphical Abstract
  • (nitrile, ketones, esters, pyridines, tetrazoles, etc.) are particularly suitable. Benzyl radicals are not reactive enough towards unactivated alkenes; they tend to accumulate in the medium and ultimately dimerise. (b) The addition product, 30, being itself a xanthate, allows the implementation of a second
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Published 18 Mar 2013

A quantitative approach to nucleophilic organocatalysis

  • Herbert Mayr,
  • Sami Lakhdar,
  • Biplab Maji and
  • Armin R. Ofial

Beilstein J. Org. Chem. 2012, 8, 1458–1478, doi:10.3762/bjoc.8.166

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  • adducts could only be isolated when the reaction mixtures containing 16 (for R2 = H) were worked up with dry K2CO3. Aqueous workup led to regeneration of the reactants. Vicario’s report that imidazoles, in contrast to triazoles and tetrazoles, do not readily undergo iminium activated additions to α,β
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Published 05 Sep 2012

Synthesis of chiral sulfoximine-based thioureas and their application in asymmetric organocatalysis

  • Marcus Frings,
  • Isabelle Thomé and
  • Carsten Bolm

Beilstein J. Org. Chem. 2012, 8, 1443–1451, doi:10.3762/bjoc.8.164

Graphical Abstract
  • . They involve both metal catalysis [64][65] as well as organocatalysis. In the latter field, chiral phosphoric acids [66][67], bicyclic diamines [68], bifunctional thioureas [69], proline ester salts [70], pyrrolidinyl tetrazoles [71], and a quinine-derived amine [72] were reported to catalyze the
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Published 03 Sep 2012

Continuous-flow enantioselective α-aminoxylation of aldehydes catalyzed by a polystyrene-immobilized hydroxyproline

  • Xacobe C. Cambeiro,
  • Rafael Martín-Rapún,
  • Pedro O. Miranda,
  • Sonia Sayalero,
  • Esther Alza,
  • Patricia Llanes and
  • Miquel A. Pericàs

Beilstein J. Org. Chem. 2011, 7, 1486–1493, doi:10.3762/bjoc.7.172

Graphical Abstract
  • ], binaphthyl-derived amines [22][23][24], pyrrolidin-2-yl-tetrazoles [25][26][27][28], thiaproline [29], 2-aminomethylpyrrolidine sulfonamide [30] and sulfonylcarboxamide [31], have been successfully used to promote the reaction. As a matter of fact, the rapid development of the methodology for the asymmetric
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Published 31 Oct 2011

Unusual behavior in the reactivity of 5-substituted-1H-tetrazoles in a resistively heated microreactor

  • Bernhard Gutmann,
  • Toma N. Glasnov,
  • Tahseen Razzaq,
  • Walter Goessler,
  • Dominique M. Roberge and
  • C. Oliver Kappe

Beilstein J. Org. Chem. 2011, 7, 503–517, doi:10.3762/bjoc.7.59

Graphical Abstract
  • , followed by translation to high-temperature/high-pressure scalable continuous flow processes (“microwave-to-flow” paradigm) [26][27][28]. A recent example involves the synthesis of 5-substituted-1H-tetrazoles via an azide–nitrile cycloaddition pathway, using sodium azide (NaN3) as an inexpensive azide
  • formed from HN3 and Fe metal at temperatures around 100 °C which represents a serious safety hazard [38]. On the other hand, it has been reported that the decomposition of tetrazoles can be catalyzed by a whole range of metals. For example, Cu powder was found to lower the decomposition temperature of
  • environment [41], in combination with the use of a flow reactor that employed a standard Al heating block as a coil heater [25]. Using this set-up, a general and scalable method for the continuous flow synthesis of 5-substituted-1H-tetrazoles via the addition of HN3 to organic nitriles was developed [25]. For
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Published 21 Apr 2011
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