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Search for "primary amine" in Full Text gives 163 result(s) in Beilstein Journal of Organic Chemistry.

Phosphonic acid: preparation and applications

  • Charlotte M. Sevrain,
  • Mathieu Berchel,
  • Hélène Couthon and
  • Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

Graphical Abstract
  • reaction, is also known as the Moedritzer–Irani reaction since it was first reported by these authors in 1966 [219]. When primary amine is used, the reaction produces a bis-phosphonic acid since the secondary amine that is generated in situ is more reactive than the starting primary amine [220]. In
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Published 20 Oct 2017

Regiodivergent condensation of 5-alkoxycarbonyl-1H-pyrrol-2,3-diones with cyclic ketazinones en route to spirocyclic scaffolds

  • Alexey Yu. Dubovtsev,
  • Maksim V. Dmitriev,
  • Аndrey N. Maslivets and
  • Michael Rubin

Beilstein J. Org. Chem. 2017, 13, 2179–2185, doi:10.3762/bjoc.13.218

Graphical Abstract
  • resulted in the discovery of an alternative mechanistic pathway. Apparently, in this case the primary amine moiety in intermediate 4 preferred a nucleophilic attack on the keto function, affording bridged hemiaminal structures 5 as kinetic products (Scheme 1) [42]. Upon extended heating, however
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Published 19 Oct 2017

Preparation of imidazo[1,2-a]-N-heterocyclic derivatives with gem-difluorinated side chains

  • Layal Hariss,
  • Kamal Bou Hadir,
  • Mirvat El-Masri,
  • Thierry Roisnel,
  • René Grée and
  • Ali Hachem

Beilstein J. Org. Chem. 2017, 13, 2115–2121, doi:10.3762/bjoc.13.208

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  • demonstrate the regiochemistry of the reaction. These cascade reactions proceed first through a Michael addition of the primary amine on the enone, followed by an intramolecular cyclization by the pyridine/pyrimidine nucleus. Unfortunately, no crystal structure could be obtained for the imidazopyrimidines and
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Published 10 Oct 2017

Mechanochemical synthesis of small organic molecules

  • Tapas Kumar Achar,
  • Anima Bose and
  • Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

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  • -promoted three-component Hantzsch pyrrole synthesis under ball-milling conditions [121]. A ketone in presence of N-iodosuccinimide (NIS) and p-toluenesulfonic acid led to α-iodoketone in 1 h. Subsequent addition of the primary amine, β-dicarbonyl compound, 5 mol % CAN and 1 equiv silver nitrate led to the
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Published 11 Sep 2017

Mechanochemical synthesis of thioureas, ureas and guanidines

  • Vjekoslav Štrukil

Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178

Graphical Abstract
  • in the solid-state before having been exposed to microwave irradiation for 1.5–4.5 minutes. In their paper, the authors state: "Aryl isothiocyanate (1 mmol) and aromatic primary amine (1 mmol) were mixed thoroughly in an agate mortar" [33]. Considering the established reactivity pattern of electron
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Published 01 Sep 2017

Aqueous semisynthesis of C-glycoside glycamines from agarose

  • Juliana C. Cunico Dallagnol,
  • Alexandre Orsato,
  • Diogo R. B. Ducatti,
  • Miguel D. Noseda,
  • Maria Eugênia R. Duarte and
  • Alan G. Gonçalves

Beilstein J. Org. Chem. 2017, 13, 1222–1229, doi:10.3762/bjoc.13.121

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  • see Supporting Information File 1. We could access pure 8 by reacting 7 and formaldehyde under reductive conditions. The reaction product 8 kept the original configuration of its parenting analogue, amine 7, because the reaction between such primary amine 7 and formaldehyde occurs via an imine
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Published 23 Jun 2017

New tricks of well-known aminoazoles in isocyanide-based multicomponent reactions and antibacterial activity of the compounds synthesized

  • Maryna V. Murlykina,
  • Maryna N. Kornet,
  • Sergey M. Desenko,
  • Svetlana V. Shishkina,
  • Oleg V. Shishkin,
  • Aleksander A. Brazhko,
  • Vladimir I. Musatov,
  • Erik V. Van der Eycken and
  • Valentin A. Chebanov

Beilstein J. Org. Chem. 2017, 13, 1050–1063, doi:10.3762/bjoc.13.104

Graphical Abstract
  • exocyclic NH2 group and an endocyclic nucleophilic center, they can act both as primary amines and as 1,3-binucleophiles, therefore, their treatments with isocyanides, aldehydes and carboxylic acids may proceed either as Ugi-4CR (aminoazole – primary amine, acid – reagent) or as GBB-3CR (aminoazole – 1,3
  • aldehydes and alkylisocyanides giving the product resulting from GBB-3CR. On the other hand, 3-amino-5-methylisoxazole in MCRs often acted as primary amine [102][103][104][105][106], that was confirmed in our case by treatment with aromatic aldehydes, alkylisocyanides and phenylpropiolic acid resulting in
  • -diaryl-1H-imidazo[1,2-b]pyrazole-7-carboxamides (Groebke–Blackburn–Bienaymé reaction). In contrast, 3-amino-5-methylisoxazole acted as a primary amine in Ugi four-component reaction with aromatic aldehydes, phenylpropiolic acid and tert-butylisocyanide giving N-(1-arylethyl-2-(tert-butylamino)-2-oxo)-N
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Published 31 May 2017

DMAP-assisted sulfonylation as an efficient step for the methylation of primary amine motifs on solid support

  • Johnny N. Naoum,
  • Koushik Chandra,
  • Dorit Shemesh,
  • R. Benny Gerber,
  • Chaim Gilon and
  • Mattan Hurevich

Beilstein J. Org. Chem. 2017, 13, 806–816, doi:10.3762/bjoc.13.81

Graphical Abstract
  • several primary amine motifs, largely due to inefficient sulfonylation. Here we show that using the superior nucleophilic base DMAP instead of the commonly used base collidine as a sulfonylation additive is essential for the introduction of the o-NBS group to these amine motifs. DFT calculations provide
  • of DMAP (Figure 1D). In the first part of the suggested mechanism, the pyridine base substitutes the chloride to form a sulfonylpyridinium intermediate. This intermediate makes the sulfonyl group a better electrophile, hence, the attack of the primary amine in the second part of the mechanism becomes
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Published 03 May 2017

Exploring endoperoxides as a new entry for the synthesis of branched azasugars

  • Svenja Domeyer,
  • Mark Bjerregaard,
  • Henrik Johansson and
  • Daniel Sejer Pedersen

Beilstein J. Org. Chem. 2017, 13, 644–647, doi:10.3762/bjoc.13.63

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  • Herein, we report the development of a synthetic strategy using [4 + 2]-cycloaddition reactions to yield endoperoxides 18–23 that contain a protected primary amine. Such intermediates serve as useful new building blocks for organic synthesis. Preliminary exploration of the chemistry of these compounds
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Published 03 Apr 2017

Brønsted acid-mediated cyclization–dehydrosulfonylation/reduction sequences: An easy access to pyrazinoisoquinolines and pyridopyrazines

  • Ramana Sreenivasa Rao and
  • Chinnasamy Ramaraj Ramanathan

Beilstein J. Org. Chem. 2017, 13, 428–440, doi:10.3762/bjoc.13.46

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  • reaction was carried out with N-benzenesulfonyliminodiacetic acid, a primary amine and CDI (2 equiv) in THF, the corresponding piperazine-2,6-dione 7a was obtained in 21% yield at room temperature (Table 1, entry 4). To facilitate the peptide bond formation DMAP has been used in conjuncture with coupling
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Published 07 Mar 2017

A chemoselective and continuous synthesis of m-sulfamoylbenzamide analogues

  • Arno Verlee,
  • Thomas Heugebaert,
  • Tom van der Meer,
  • Pavel I. Kerchev,
  • Frank Van Breusegem and
  • Christian V. Stevens

Beilstein J. Org. Chem. 2017, 13, 303–312, doi:10.3762/bjoc.13.33

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  • -sulfamoylbenzamide analogues a) Continuous process with primary amines as F1: Triethylamine and a primary amine (F1) were dissolved in acetonitrile (c = 40 mM), m-chlorosulfonylbenzoyl chloride (F2) was dissolved in the same solvent in a separate volumetric flask (c = 40 mM). A third solution was prepared with
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Published 16 Feb 2017

Towards the development of continuous, organocatalytic, and stereoselective reactions in deep eutectic solvents

  • Davide Brenna,
  • Elisabetta Massolo,
  • Alessandra Puglisi,
  • Sergio Rossi,
  • Giuseppe Celentano,
  • Maurizio Benaglia and
  • Vito Capriati

Beilstein J. Org. Chem. 2016, 12, 2620–2626, doi:10.3762/bjoc.12.258

Graphical Abstract
  • recently reported that L-proline-catalysed direct aldol reactions may be successfully carried out also in deep eutectic solvents (DESs) [20][21][22]. Recently, our group reported on the possibility of running organocatalyzed, stereoselective reactions in DESs, promoted by an enantiopure primary amine, with
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Published 05 Dec 2016

The in situ generation and reactive quench of diazonium compounds in the synthesis of azo compounds in microreactors

  • Faith M. Akwi and
  • Paul Watts

Beilstein J. Org. Chem. 2016, 12, 1987–2004, doi:10.3762/bjoc.12.186

Graphical Abstract
  • (from 82% to 95%). The flow rate of the reactants (diazotized primary amine and coupler) was also investigated as mentioned earlier on. As is shown in Figure 4, based on the predicted conversion, there is no difference in carrying out the reaction at either 0.03 mL/min or 0.7 mL/min. Moving on to the
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Published 06 Sep 2016

Towards potential nanoparticle contrast agents: Synthesis of new functionalized PEG bisphosphonates

  • Souad Kachbi-Khelfallah,
  • Maelle Monteil,
  • Margery Cortes-Clerget,
  • Evelyne Migianu-Griffoni,
  • Jean-Luc Pirat,
  • Olivier Gager,
  • Julia Deschamp and
  • Marc Lecouvey

Beilstein J. Org. Chem. 2016, 12, 1366–1371, doi:10.3762/bjoc.12.130

Graphical Abstract
  • in moderate 62% and 68% yields. In order to access available PEG-HMBPs functionalized with a primary amine or a carboxylic acid group usable in peptidic coupling with various molecules for example, the HMBP-PEG-COOH 23 was synthesized (Scheme 5). This compound was obtained in six steps starting from
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Published 04 Jul 2016

Conjugate addition–enantioselective protonation reactions

  • James P. Phelan and
  • Jonathan A. Ellman

Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116

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  • protonation of vinyl ketones. Using primary amine catalyst (S,S)-119, the authors were able to catalyze the Friedel–Crafts addition of indoles 117 to vinyl ketones 118 followed by enantioselective protonation (Scheme 27) [52]. During optimization it was found that addition of a weak acid, 2-naphthoic acid
  • review, Lou and co-workers reported an additional example of conjugate addition–enantioselective protonation involving an α,β-unsaturated ketone. In the new report, a chiral primary amine catalyzed conjugate addition of a 1,3-diketone nucleophile into an in situ generated ortho-quinone methide was
  • ketones by enamine catalysis. Curtin–Hammett controlled enantioselective addition of indole. Luo and Cheng’s enantioselective additions to α-branched vinyl ketones. Lou’s reduction–conjugate addition–enantioselective protonation. Luo and Cheng’s primary amine-catalyzed addition of indoles to α-substituted
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Published 15 Jun 2016

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

  • Barry M. Trost,
  • Michael C. Ryan and
  • Meera Rao

Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110

Graphical Abstract
  • sulfinamides [48]. The application of this method to the synthesis of our chiral sulfoxide tethers is presented in Scheme 4. Tosyl protection of the primary amine of (+)-norephedrine and treatment with thionyl chloride furnishes chiral oxathiazolidine 2-oxide 7 as a single diastereomer in 87% yield over two
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Published 07 Jun 2016

Towards the total synthesis of keramaphidin B

  • Pavol Jakubec,
  • Alistair J. M. Farley and
  • Darren J. Dixon

Beilstein J. Org. Chem. 2016, 12, 1096–1100, doi:10.3762/bjoc.12.104

Graphical Abstract
  • turn be synthesised by an aminolysis/oxidation/olefination sequence of the terminal alcohol 6, following traceless nitro group removal. 5-Nitropiperidin-2-one 6 in turn could be accessed by a nitro-Mannich lactamisation cascade reaction between Michael adduct 7, formaldehyde and a suitable primary
  • amine, following our well-established protocol [6][7][8][9][10][11][12]. The key quaternary stereocentre of keramaphidin B, we envisaged, would be installed through an enantio- and diastereoselective organocatalytic Michael addition [13][14][15] between pronucleophile 8 and the known substituted furanyl
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Published 30 May 2016

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

  • Bin Yu,
  • Hui Xing,
  • De-Quan Yu and
  • Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

Graphical Abstract
  • -derived primary amine catalysts (cat. 15 and 16) and achieved the asymmetric aldol reaction of 1,1-dimethoxyacetone with isatins (Scheme 30) [46]. The reactions were carried out at room temperature using 10% catalyst loading and trichloroacetic acid (TCA) as the additive, affording the corresponding 3
  • -hydroxyoxindoles in excellent yields (up to 96% yield) and with high enantioselectivies (up to 97% ee), even for N-unsubstituted isatin derivatives. Besides, this protocol showed a broad substrate scope and good tolerance toward different functional groups. TCA promoted the formation of an enamine from the primary
  • amine of the catalyst and ketone substrate and protonation of the tertiary amino group. The protonated amine then served as hydrogen bond donor to activate the carbonyl group of isatin substrates, thereby facilitating the aldol addition. Interestingly, the authors obtained the R-/S-enantiomer by using
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Published 18 May 2016

A robust synthesis of 7,8-didemethyl-8-hydroxy-5-deazariboflavin

  • Matthias Bender,
  • Henrik Mouritsen and
  • Jens Christoffers

Beilstein J. Org. Chem. 2016, 12, 912–917, doi:10.3762/bjoc.12.89

Graphical Abstract
  • deprotection with iodine instead of mercury compounds) we have improved the synthesis of aldehyde 9. The latter compound was then transformed to the protected ribitylamine 10 via the oxime, which was reduced with LiAlH4. Primary amine 10 was then converted with chlorouracil 3, which was actually the key
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Published 06 May 2016

Synthesis of 2,1-benzisoxazole-3(1H)-ones by base-mediated photochemical N–O bond-forming cyclization of 2-azidobenzoic acids

  • Daria Yu. Dzhons and
  • Andrei V. Budruev

Beilstein J. Org. Chem. 2016, 12, 874–881, doi:10.3762/bjoc.12.86

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  • the reaction mixture [30] and obtained a maximum yield of 20% and 50%, respectively, at a water content of 50%. Under these conditions, no formation of the primary amine 4 (a product of the typical triplet nitrene reaction (Scheme 1, intermediate D)) was detected. The replacement of the aprotic
  • presence of isoprene as a triplet nitrene quencher. The addition of isoprene lead to a significantly increased yield of 3-amino-6-nitro-2,1-benzisoxazole and an insignificant decrease of the primary amine yield. Thus it was demonstrated that the formation of 3-amino-6-nitro-2,1-benzisoxazole goes through
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Published 04 May 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

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  • will be summarized. Initially, the use of primary amine-thioureas as organocatalysts for the above transformation is being discussed, followed by the examples employing secondary amine-thioureas. Finally, the use of tertiary amine-thioureas and miscellaneous examples are presented. Keywords: multiple
  • organocatalysts. Review Primary amine-thioureas as organocatalysts promoting asymmetric transformations that lead to a six-membered ring As discussed earlier, except from the activation of the substrates with the formation of the corresponding enamines or iminium ions, the synthesis of enantiopure products can be
  • of a bifunctional catalyst. The first family of these bifunctional catalysts, that are going to be discussed, are the "primary amine-thioureas". Initially, catalyst 4 was studied as an organocatalyst in the addition of isobutyraldehyde (1) to (E)-methyl 2-oxo-4-phenylbut-3-enoate (2) for the
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Published 10 Mar 2016

Cupreines and cupreidines: an established class of bifunctional cinchona organocatalysts

  • Laura A. Bryant,
  • Rossana Fanelli and
  • Alexander J. A. Cobb

Beilstein J. Org. Chem. 2016, 12, 429–443, doi:10.3762/bjoc.12.46

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  • co-workers who developed an organocatalytic transamination process using the cupreine catalyst CPN-81, which is substituted with n-butyl at the 9-OH position [59]. In this report, the α-ketoester 79 was reacted with the primary amine o-ClC6H4CH2NH2 80 in the presence of the catalyst. Once again, the
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Published 07 Mar 2016

Highly stable and reusable immobilized formate dehydrogenases: Promising biocatalysts for in situ regeneration of NADH

  • Barış Binay,
  • Dilek Alagöz,
  • Deniz Yildirim,
  • Ayhan Çelik and
  • S. Seyhan Tükel

Beilstein J. Org. Chem. 2016, 12, 271–277, doi:10.3762/bjoc.12.29

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  • different nucleophiles highly abundant in the protein surface such as primary amine, sulfhydryl and carboxylic groups [21]. In this study, Immobead 150 was used as epoxy group containing supports for the immobilization of C. methylica FDH (Figure 1a). The amount of bound protein was determined as 85% of the
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Published 12 Feb 2016

A novel and practical asymmetric synthesis of dapoxetine hydrochloride

  • Yijun Zhu,
  • Zhenren Liu,
  • Hongyan Li,
  • Deyong Ye and
  • Weicheng Zhou

Beilstein J. Org. Chem. 2015, 11, 2641–2645, doi:10.3762/bjoc.11.283

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  • temperature and dissociated with NaHCO3 to give the primary amine 6 in 90.0% yield. The reductive amination of 6 under Eschweiler–Clarke conditions furnished (S)-dapoxetine 7 with excellent enantiopurity (99.3% ee) in 74.7% yield. After salt formation and recrystallization, the target compound 1 was obtained
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Published 17 Dec 2015

Synthesis of bi- and bis-1,2,3-triazoles by copper-catalyzed Huisgen cycloaddition: A family of valuable products by click chemistry

  • Zhan-Jiang Zheng,
  • Ding Wang,
  • Zheng Xu and
  • Li-Wen Xu

Beilstein J. Org. Chem. 2015, 11, 2557–2576, doi:10.3762/bjoc.11.276

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  • low yield when the alkynes or azides were linked directly with a hindered group or an aromatic moiety. In 2012, Xu and co-workers disclosed that both the secondary and primary amine-functionalized polysiloxanes were good ligands for the copper-catalyzed Huisgen reaction of organic azides and alkynes
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Published 11 Dec 2015
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