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Search for "substitution reaction" in Full Text gives 133 result(s) in Beilstein Journal of Organic Chemistry.

First DMAP-mediated direct conversion of Morita–Baylis–Hillman alcohols into γ-ketoallylphosphonates: Synthesis of γ-aminoallylphosphonates

  • Marwa Ayadi,
  • Haitham Elleuch,
  • Emmanuel Vrancken and
  • Farhat Rezgui

Beilstein J. Org. Chem. 2016, 12, 2906–2915, doi:10.3762/bjoc.12.290

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  • nucleophilic substitution reaction worked also well and gave the allylphosphonate 4a in 90% yield within 1 h (Table 3, entry 1). More interestingly, repeating this reaction without DMAP and under solvent-free conditions at 80 °C gave, in only 30 min, the phosphonate 4a in 92% yield (Table 3, entry 2
  • conditions, the γ-tosylaminophosphonates 6a–d were obtained in good yields (63–70%) (Table 4, entries 1–4). Scheme 6 illustrates a possible mechanism for the I2-catalyzed substitution reaction of γ-hydroxyallylphosphonate 5 with tosylamines. This could first involve an activation of the hydroxy moiety of
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Published 30 Dec 2016

Et3B-mediated and palladium-catalyzed direct allylation of β-dicarbonyl compounds with Morita–Baylis–Hillman alcohols

  • Ahlem Abidi,
  • Yosra Oueslati and
  • Farhat Rezgui

Beilstein J. Org. Chem. 2016, 12, 2402–2409, doi:10.3762/bjoc.12.234

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  • generate a π-allylpalladium intermediate I that further undergoes a nucleophilic substitution reaction with the β-keto ester carbanion derived from 2j, affording the monoallylated compound 3j. The conversion of the keto ester 3j into the tricyclic product 6j was further performed through an intramolecular
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Published 15 Nov 2016

Efficient mechanochemical synthesis of regioselective persubstituted cyclodextrins

  • Laszlo Jicsinszky,
  • Marina Caporaso,
  • Katia Martina,
  • Emanuela Calcio Gaudino and
  • Giancarlo Cravotto

Beilstein J. Org. Chem. 2016, 12, 2364–2371, doi:10.3762/bjoc.12.230

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  • simplicity and flexibility [18][19][20][21]. While the mechanochemical manipulation of covalent bonds is hardly a brand new concept, its diffusion into carbohydrate chemistry, and particularly into CD derivatization, has been rather slow [22][23]. The ability of HEBM to favour the nucleophilic substitution
  • reaction of 6I-monotosyl-β-CD has been demonstrated in a previous article [22]. Most interestingly, the side reactions that appear to be unavoidable in the classical solution syntheses can be eliminated in the solvent-free method described for the preparation of various CD derivatives. HEBM was found to be
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Published 10 Nov 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

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  • is also dependent on the kind of coupling compound used [31]. For example, phenols are successfully coupled in alkaline conditions in which the phenolate ion is formed. These conditions provide the desired electron-releasing group thus facilitating the electrophilic substitution reaction to afford
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Published 06 Sep 2016

Methylpalladium complexes with pyrimidine-functionalized N-heterocyclic carbene ligands

  • Dirk Meyer and
  • Thomas Strassner

Beilstein J. Org. Chem. 2016, 12, 1557–1565, doi:10.3762/bjoc.12.150

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  • should be active according to the proposed catalytic cycle, which starts with an electrophilic substitution reaction. We therefore set out to synthesize the corresponding methyl complexes for the “hybrid ligand” with chloro- and trifluoroacetato ligands. Results and Discussion Synthesis Some time ago we
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Published 21 Jul 2016

On the mechanism of imine elimination from Fischer tungsten carbene complexes

  • Philipp Veit,
  • Christoph Förster and
  • Katja Heinze

Beilstein J. Org. Chem. 2016, 12, 1322–1333, doi:10.3762/bjoc.12.125

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  • of ferrocenyl carbene complexes has been extensively investigated [25][26][27][34][35][36][37][38][39]. A second ferrocenyl unit can be incorporated by employing aminoferrocene (Fc-NH2) [40][41] in a nucleophilic substitution reaction [27]. The trimetallic complex Cr(CO)5(E-2) with the
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Published 27 Jun 2016

Synthesis of 2-oxindoles via 'transition-metal-free' intramolecular dehydrogenative coupling (IDC) of sp2 C–H and sp3 C–H bonds

  • Nivesh Kumar,
  • Santanu Ghosh,
  • Subhajit Bhunia and
  • Alakesh Bisai

Beilstein J. Org. Chem. 2016, 12, 1153–1169, doi:10.3762/bjoc.12.111

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  • substitution reaction on C-iodo product 24 from the adjacent aryl group (Scheme 8). Thus, the possibilty of the addition at the 2-position of electron-rich N-acylated aniline 3a to the tertiary iodide intermediate was also investigated. Towards this, we thought of synthesizing the C-iodo intermediate using N
  • 4a in 80–85% yield when the reaction was carried out at elevated temperature (Scheme 8). We thought there could be the possibility of a substitution reaction of iodide compound 24 prepared in-situ to form directly 2-oxindole 4a under elevated temperature. Thus, it was decided to carry out the C
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Published 08 Jun 2016

Modular synthesis of the pyrimidine core of the manzacidins by divergent Tsuji–Trost coupling

  • Sebastian Bretzke,
  • Stephan Scheeff,
  • Felicitas Vollmeyer,
  • Friederike Eberhagen,
  • Frank Rominger and
  • Dirk Menche

Beilstein J. Org. Chem. 2016, 12, 1111–1121, doi:10.3762/bjoc.12.107

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  • , Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany 10.3762/bjoc.12.107 Abstract The design, development and application of an efficient procedure for the concise synthesis of the 1,3-syn- and anti-tetrahydropyrimidine cores of manzacidins are reported. The intramolecular allylic substitution reaction of a
  • allylic substitution reaction of a joint precursor 5. Subsequently this strategy is successfully applied to the synthesis of the authentic pyrimidine cores 3 and 4 of manzacidin A (1) and ent-manzacidin C (2). Results and Discussion General synthetic concept As part of our ongoing efforts to the design of
  • groups [38][39][40][41][42][43], is based on a sequential nucleophilic addition and an intramolecular allylic substitution reaction. It relies on the coupling of different homoallylic nucleophiles of general type 6 to diverse electrophiles 7 such as Michael acceptors, or heteroolefins as for example
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Published 02 Jun 2016

Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(−)-myrtenol nitrate

  • Sean P. Bew,
  • Glyn D. Hiatt-Gipson,
  • Graham P. Mills and
  • Claire E. Reeves

Beilstein J. Org. Chem. 2016, 12, 1081–1095, doi:10.3762/bjoc.12.103

Graphical Abstract
  • studied their ability to undergo an ‘allylic halide for allylic nitrate’ substitution reaction which we demonstrate generates (E)- and (Z)-3-methyl-4-hydroxybut-2-enyl nitrate, and (E)- and (Z)-2-methyl-4-hydroxybut-2-enyl nitrates (‘isoprene nitrates’) in 66–80% overall yields. Using NOESY experiments
  • our protocol proceeds via the application of Horner–Wadsworth–Emmons Chemistry that generates readily functionalized motifs that undergo an all but previously non-existent, allylic ‘halide for nitrate’ substitution reaction. A consequence of the broader importance of organic nitrates we envisage our
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Published 27 May 2016

1H-Imidazol-4(5H)-ones and thiazol-4(5H)-ones as emerging pronucleophiles in asymmetric catalysis

  • Antonia Mielgo and
  • Claudio Palomo

Beilstein J. Org. Chem. 2016, 12, 918–936, doi:10.3762/bjoc.12.90

Graphical Abstract
  • -catalyzed allylation substitution reaction of oxazol-4(5H)-ones and thiazol-4(5H)-ones to afford enantioenriched tertiary alcohols and thioethers (Scheme 19) [42]. In this case the diastereoselectivity is controlled by cations, in contrast to most of the described protocols wherein it is modulated by anions
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Published 09 May 2016

Aluminacyclopentanes in the synthesis of 3-substituted phospholanes and α,ω-bisphospholanes

  • Vladimir A. D’yakonov,
  • Alevtina L. Makhamatkhanova,
  • Rina A. Agliullina,
  • Leisan K. Dilmukhametova,
  • Tat’yana V. Tyumkina and
  • Usein M. Dzhemilev

Beilstein J. Org. Chem. 2016, 12, 406–412, doi:10.3762/bjoc.12.43

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  • (Scheme 5). Thus bisaluminacyclopentane 9a, synthesized by catalytic cycloalumination of 1,7-octadiene, was subjected without isolation to the substitution reaction with aryl(alkyl)dichlorophosphine with replacement of Al by Р (ca. 20 °С, 30 min) to give bisphospholane 10a as a mixture of isomers in a
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Published 02 Mar 2016

Interactions of cyclodextrins and their derivatives with toxic organophosphorus compounds

  • Sophie Letort,
  • Sébastien Balieu,
  • William Erb,
  • Géraldine Gouhier and
  • François Estour

Beilstein J. Org. Chem. 2016, 12, 204–228, doi:10.3762/bjoc.12.23

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  • substitution reaction in a one-pot manner. Methyl iodobenzoates were introduced following this approach (Scheme 7, 33a,b), unfortunately, degradation occurred during the final oxidation step to obtain the α-nucleophile group [87]. The 3-monosubstituted derivative 41 was successfully obtained starting from the
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Published 05 Feb 2016

Facile synthesis of 4H-chromene derivatives via base-mediated annulation of ortho-hydroxychalcones and 2-bromoallyl sulfones

  • Srinivas Thadkapally,
  • Athira C. Kunjachan and
  • Rajeev S. Menon

Beilstein J. Org. Chem. 2016, 12, 16–21, doi:10.3762/bjoc.12.3

Graphical Abstract
  •  1, path a). Bromoallyl sulfones 2a,b partake in a cesium carbonate-mediated formal vinylic substitution reaction with heteronucleophiles to afford valuable multifunctional building blocks [23]. For example, the reaction of 2a with 4-chlorophenol afforded the enol ether 3 in 84% yield (Scheme 1, path
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Published 06 Jan 2016

Recent advances in copper-catalyzed asymmetric coupling reactions

  • Fengtao Zhou and
  • Qian Cai

Beilstein J. Org. Chem. 2015, 11, 2600–2615, doi:10.3762/bjoc.11.280

Graphical Abstract
  • ’ regioselectivity, creating a new stereogenic center [59][60]. In 1995, Bäckvall et al. reported the first example of an asymmetric allylic substitution reaction catalyzed by a chiral copper complex, giving a moderate enantioselectivity (42% ee) in Grignard reactions with allylic acetates. The enantiomeric excess
  • protocol was demonstrated by the concise enantioselective syntheses of the Pummerer ketone (Scheme 27) [67]. In 2012, Sawamura et al. reported a Cu(I)-DTBM-SEGPHOS-catalyzed enantioselective allylic substitution reaction with alkylboron compounds [68]. In this report, alkyl-9-BBN reagents for the first
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Published 15 Dec 2015

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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  • electrophilic substitution reaction, the occurrence of powerful new synthetic strategies such as transition metal-catalyzed C–H activation brought new opportunities to the synthesis of more diversely halogenated products by enabling the halogenation of more challenging substrates by more selective
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Published 09 Nov 2015

Towards inhibitors of glycosyltransferases: A novel approach to the synthesis of 3-acetamido-3-deoxy-D-psicofuranose derivatives

  • Maroš Bella,
  • Miroslav Koóš and
  • Chun-Hung Lin

Beilstein J. Org. Chem. 2015, 11, 1547–1552, doi:10.3762/bjoc.11.170

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  • step. An analytically pure sample of 3 was obtained by additional column chromatography. In order to increase the yield of azide 3 by replacing 3-O-mesylate 2 with the corresponding 3-O-triflate in the nucleophilic substitution reaction with sodium azide, the O-protected mannitol derivative 1 was
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Published 04 Sep 2015

Ruthenium indenylidene “1st generation” olefin metathesis catalysts containing triisopropyl phosphite

  • Stefano Guidone,
  • Fady Nahra,
  • Alexandra M. Z. Slawin and
  • Catherine S. J. Cazin

Beilstein J. Org. Chem. 2015, 11, 1520–1527, doi:10.3762/bjoc.11.166

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  • (OiPr)3. Full conversion of the starting material was observed affording complex 2 (Scheme 2). Unfortunately, all attempts to purify 2 failed due to the presence of PCy3 decomposition products. The PPh3 adduct Ind-I0 was then employed as alternative starting material for the ligand substitution reaction
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Published 01 Sep 2015

Selected synthetic strategies to cyclophanes

  • Sambasivarao Kotha,
  • Mukesh E. Shirbhate and
  • Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

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Published 29 Jul 2015

One-pot odourless synthesis of thioesters via in situ generation of thiobenzoic acids using benzoic anhydrides and thiourea

  • Mohammad Abbasi and
  • Reza Khalifeh

Beilstein J. Org. Chem. 2015, 11, 1265–1273, doi:10.3762/bjoc.11.141

Graphical Abstract
  • [51] or thioacetamide [52], a benzoic anhydride undergoes a nucleophilic acyl substitution reaction with thiourea to produce the corresponding S-benzoylisothiouronium salt as an intermediate. After addition of H2O to the reaction mixture, the salt is hydrolyzed by the hydroxide anion to generate the
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Published 28 Jul 2015

Development of variously functionalized nitrile oxides

  • Haruyasu Asahara,
  • Keita Arikiyo and
  • Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2015, 11, 1241–1245, doi:10.3762/bjoc.11.138

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  • , entries 1–4). In addition, the nucleophilic substitution also proceeded by employing neutral amines. The reaction of 8 with propylamine proceed smoothly, leading to N-propylamides 9c and 10c (Table 2, entries 5 and 6). The substitution reaction was influenced by the bulkiness of the amines. Heating at 120
  • °C was required for the substitution reaction by sec-butylamine. However, in the case of tert-butylamine, even when the reaction was conducted in a sealed tube at 120 °C, only a small amount of amide was observed (Table 2, entries 7–10). On the other hand, a cyclic secondary amine, pyrrolidine
  • amines underwent the substitution reaction, leading to 5c–f in good to moderate yields (Table 3, entries 3–6). It was noteworthy that, because of high reactivity of 12 caused by the isoxazole ring [20], the methylamino group could be replaced by a bulky tert-butylamino moiety. Conversion of the N
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Published 23 Jul 2015

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

  • Marcus Baumann and
  • Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

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  • etc.) [86]. The synthetic strategy relied on reacting chlorodiphenylmethane (93) with an excess of dimethylaminoethanol (94) via a nucleophilic substitution reaction (Scheme 16). As both starting materials are liquid at ambient temperature the use of a solvent could be avoided allowing direct
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Published 17 Jul 2015

An unusually stable chlorophosphite: What makes BIFOP–Cl so robust against hydrolysis?

  • Roberto Blanco Trillo,
  • Jörg M. Neudörfl and
  • Bernd Goldfuss

Beilstein J. Org. Chem. 2015, 11, 313–322, doi:10.3762/bjoc.11.36

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  • computational analysis of the hydrolysis of the chlorophosphites BIFOP–Cl (1) and O–BIFOP–Cl (3, as well as the smaller model system 2-chloro-1,3,2-dioxaphospholane 8) provides further comparison of the >P–Cl reactivity. The nucleophilic substitution reaction takes place at a triple-coordinated chlorophosphite
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Published 04 Mar 2015

The Shono-type electroorganic oxidation of unfunctionalised amides. Carbon–carbon bond formation via electrogenerated N-acyliminium ions

  • Alan M. Jones and
  • Craig E. Banks

Beilstein J. Org. Chem. 2014, 10, 3056–3072, doi:10.3762/bjoc.10.323

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  • and release cation pool method [42]. Schematic illustration of the anodic substitution reaction system using acoustic emulsification. Figure redrawn from reference [45]. Example of a chiral auxiliary Shono-oxidation intermediate [69]. Application of anodic oxidation to the generation of new carbon
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Published 18 Dec 2014

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

  • Lidija-Marija Tumir,
  • Marijana Radić Stojković and
  • Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

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  • used readily available N-(o-halobenzyl)arylamines as starting materials [17]. The o-haloarylbenzylamines (obtained by nucleophilic substitution of various anilines with 2-iodobenzyl chloride) gave the corresponding amide anions by an SRN1 substitution reaction in NH3 or DMSO as solvent under
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Published 10 Dec 2014

Facile synthesis of 1-alkoxy-1H-benzo- and 7-azabenzotriazoles from peptide coupling agents, mechanistic studies, and synthetic applications

  • Mahesh K. Lakshman,
  • Manish K. Singh,
  • Mukesh Kumar,
  • Raghu Ram Chamala,
  • Vijayender R. Yedulla,
  • Domenick Wagner,
  • Evan Leung,
  • Lijia Yang,
  • Asha Matin and
  • Sadia Ahmad

Beilstein J. Org. Chem. 2014, 10, 1919–1932, doi:10.3762/bjoc.10.200

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  • ability of BtO− to function as a nucleofuge, led us to explore its displacement. In this context, several 1-alkoxy-1H-benzotriazoles obtained from benzylic alcohols underwent substitution reaction with a range of nucleophiles, and a simple alkyl derivative also underwent reaction although the reaction was
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Published 19 Aug 2014
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