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Search for "addition reaction" in Full Text gives 181 result(s) in Beilstein Journal of Organic Chemistry.

Solvent-free synthesis of enantioenriched β-silyl nitroalkanes under organocatalytic conditions

  • Akhil K. Dubey and
  • Raghunath Chowdhury

Beilstein J. Org. Chem. 2021, 17, 2642–2649, doi:10.3762/bjoc.17.177

Graphical Abstract
  • organosilanes [29][37][38], we present herein an organocatalyzed conjugate addition reaction of nitromethane to β-silyl enones to afford chiral β-silyl nitroalkanes (Scheme 1). Notably, the developed method was not only carried out under solvent-free conditions at room temperature but was found to be tolerant
  • the best of our knowledge, organocatalyzed or metal-catalyzed enantioselective conjugate additions of nitroalkanes to β-silyl enones are not yet known. Results and Discussion The optimization study began with the conjugate addition reaction between β-TMS enone 1a and nitromethane (2) as the model
  • limitations of this enantioselective conjugate addition reaction. Under the optimized reaction conditions, the conjugate addition reaction of nitromethane (2) to a variety of β-silylenones 1 was carried out and the results are summarized in Scheme 2. β-Silylenones bearing electron-donating, electron
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Published 27 Oct 2021

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

  • Pratibha Sharma,
  • Raakhi Gupta and
  • Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

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  • reactions [34][35]. In 2015, Zhao et al. synthesized spiro[pyrrolidine-3,3'-oxindoles] 29 in single step by asymmetric cascade aza-Michael/Michael addition reaction between 4-tosylaminobut-2-enoates 27 and 3-ylideneoxindoles 26 catalyzed by a chiral bifunctional tertiary amine, squaramide (cat. 28) which
  • afforded the corresponding adducts in good yields ranging from 72–99% with excellent diastereoselectivity (up to >99:1 dr) and enantioselectivity (>99% ee) (Table 6) [36]. In another report, Yang et al. accomplished a highly asymmetric cascade aza-Michael/Michael addition reaction for the synthesis of
  • acids have been shown to catalyze the reactions via single or double hydrogen bonding [57][58]. Saito et al. accomplished the chiral phosphoric acid-catalyzed intramolecular aza-Michael addition reaction of N-unprotected 2-aminophenyl vinyl ketones 90 to obtain chiral 2-substituted 2,3-dihydro-4
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Published 18 Oct 2021

Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives

  • Yi Liu,
  • Puying Luo,
  • Yang Fu,
  • Tianxin Hao,
  • Xuan Liu,
  • Qiuping Ding and
  • Yiyuan Peng

Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163

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  • dibromopyrroles 38, respectively. Subsequently, Punniyamurthy and co-workers also described the copper-catalyzed cascade cyclization of 2-nitro-1,3-enynes 34 to tetrasubstituted pyrroles 39 (Scheme 14) [58]. Through screening the conditions, the Cu(OTf)2-promoted (5 mol %) annulation addition reaction of 2-nitro
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Published 22 Sep 2021

Synthesis of phenanthridines via a novel photochemically-mediated cyclization and application to the synthesis of triphaeridine

  • Songeziwe Ntsimango,
  • Kennedy J. Ngwira,
  • Moira L. Bode and
  • Charles B. de Koning

Beilstein J. Org. Chem. 2021, 17, 2340–2347, doi:10.3762/bjoc.17.152

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  • ], rhodium-mediated alkyne [2 + 2 + 2] cycloaddition reactions [3], and the palladium-catalysed aerobic domino Suzuki coupling/Michael addition reaction [4]. The most attractive and common strategies to phenanthridines rely on intramolecular cyclizations of various ortho-functionalized biaryl precursors
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Published 08 Sep 2021

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

  • Pezhman Shiri,
  • Ali Mohammad Amani and
  • Thomas Mayer-Gall

Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114

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  • process displayed good regioselectivity (Scheme 10) [23]. The authors proposed that the reaction may proceed through the mechanism illustrated in Scheme 11. Initially, EDAM 24 is treated with an azide source and subsequently, the intermediate 26 is formed through 1,2-addition reaction. The intermediate 26
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Published 13 Jul 2021

Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances

  • Thiago S. Silva and
  • Fernando Coelho

Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112

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  • substituents. Electron-withdrawing groups render the generated radical more susceptible to reaction with electron-rich compounds, whereas substituents that donate electronic density increase the addition reaction rate to electron-deficient ones (Michael acceptors, for example) [55]. Another beneficial aspect
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Published 07 Jul 2021

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

  • Guido Gambacorta,
  • James S. Sharley and
  • Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

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Published 18 May 2021

Recent advances in palladium-catalysed asymmetric 1,4–additions of arylboronic acids to conjugated enones and chromones

  • Jan Bartáček,
  • Jan Svoboda,
  • Martin Kocúrik,
  • Jaroslav Pochobradský,
  • Alexander Čegan,
  • Miloš Sedlák and
  • Jiří Váňa

Beilstein J. Org. Chem. 2021, 17, 1048–1085, doi:10.3762/bjoc.17.84

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  • combination provided the product in an excellent yield (60–99%) and enantioselectivity (up to 97% ee; Table 4), the only exception being the addition of an ortho-substituted boronic acid (entry 5, Table 4) [36]. In 2008, the same group further expanded the substrate scope of the addition reaction to electron
  • -rich chalcones. The products obtained after the addition reaction with arylboronic acids were further subjected to a regioselective Bayer–Villiger oxidation (Table 5) [3]. An enhanced protocol for the synthesis of 4-aryldihydrocoumarins (Table 6) was also presented [3], which was already mentioned
  • %; 85% ee), but the reaction times were very short (Scheme 7) [41]. In 2011, the groups of Hayashi and Chujo studied Pd complexes of diphosphacrown ethers [42]. The macrocyclic Pd complex PdL5 in combination with AgSbF6 or AgOTf was tested for the addition reaction of various arylboronic acids to 2
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Published 10 May 2021

Synthetic accesses to biguanide compounds

  • Oleksandr Grytsai,
  • Cyril Ronco and
  • Rachid Benhida

Beilstein J. Org. Chem. 2021, 17, 1001–1040, doi:10.3762/bjoc.17.82

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Published 05 May 2021

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

  • Shivani Gulati,
  • Stephy Elza John and
  • Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

Graphical Abstract
  • -methyl-2H-pyran-2-one and arylglyoxal to form intermediate A. Michael addition of amine to intermediate A gives B which further undergoes an intramolecular nucleophilic addition reaction to yield C which on cyclization and with subsequent loss of water from D produce the desired products 34. Meshram and
  • products 143b. The proposed mechanism in Scheme 58 depicts the formation of intermediate A from condensation of arylglyoxal and pyrazolylamine protonated by p-TsOH with subsequent dehydration. An enone intermediate generated from the carbonyl addition reaction of intermediate A with imine B transforms into
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Published 19 Apr 2021
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  • conclusion, we report the enantioselective organocatalytic sulfa-Michael addition reaction of naphthalene-1-thiol to trans-chalcones, in the presence of a new bifunctional quinine derived sulfonamide organocatalyst. The adducts obtained with moderate to excellent ee values are β-naphthyl-β-sulfanyl ketones
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Published 18 Feb 2021

Synthetic strategies of phosphonodepsipeptides

  • Jiaxi Xu

Beilstein J. Org. Chem. 2021, 17, 461–484, doi:10.3762/bjoc.17.41

Graphical Abstract
  • tetraoxyspirophosphoranes to imines The addition reaction of the P–H bond of tetraoxyspirophosphoranes 199 to long-chain imines 200 of benzaldehyde, acetaldehyde, and dodecanal at room temperature generated the corresponding (α-aminoalkyl)spirophosphoranes 201 via the Pudovik reaction. The one-pot selective hydrolysis of
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Published 16 Feb 2021

Selective synthesis of α-organylthio esters and α-organylthio ketones from β-keto esters and sodium S-organyl sulfurothioates under basic conditions

  • Jean C. Kazmierczak,
  • Roberta Cargnelutti,
  • Thiago Barcellos,
  • Claudio C. Silveira and
  • Ricardo F. Schumacher

Beilstein J. Org. Chem. 2021, 17, 234–244, doi:10.3762/bjoc.17.24

Graphical Abstract
  • -rich N-heterocycles [2][3][4], decarboxylative cross-coupling reactions with propiolic acid derivatives [5], Michael addition reaction [6], cross-couplings catalyzed by Pd [7] and Cu salts [8][9], the preparation of symmetrical and nonsymmetrical disulfides [10][11], and the synthesis of β-acetamido
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Published 26 Jan 2021

A sustainable strategy for the straightforward preparation of 2H-azirines and highly functionalized NH-aziridines from vinyl azides using a single solvent flow-batch approach

  • Michael Andresini,
  • Leonardo Degannaro and
  • Renzo Luisi

Beilstein J. Org. Chem. 2021, 17, 203–209, doi:10.3762/bjoc.17.20

Graphical Abstract
  • corresponding 2H-azirines in a microfluidic reactor, overcoming the hazards associated with this transformation under batch conditions. A small library of functionalized aryl and alkyl-substituted NH-aziridines has been created under operationally simple conditions. Notably, the addition reaction was found to
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Published 20 Jan 2021

Synthesis of aryl 2-bromo-2-chloro-1,1-difluoroethyl ethers through the base-mediated reaction between phenols and halothane

  • Yukiko Karuo,
  • Ayaka Kametani,
  • Atsushi Tarui,
  • Kazuyuki Sato,
  • Kentaro Kawai and
  • Masaaki Omote

Beilstein J. Org. Chem. 2021, 17, 89–96, doi:10.3762/bjoc.17.9

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  • the further application of compound 2o in a cyclization reaction. Upon the treatment of 2o with zinc and chlorotrimethylsilane (TMSCl), the intramolecular 1,4-addition reaction of 2o proceeded to give the 2,2-gem-difluorochromane 3 in low yield (Scheme 3). Next, we moved on consideration of the
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Published 11 Jan 2021

An atom-economical addition of methyl azaarenes with aromatic aldehydes via benzylic C(sp3)–H bond functionalization under solvent- and catalyst-free conditions

  • Divya Rohini Yennamaneni,
  • Vasu Amrutham,
  • Krishna Sai Gajula,
  • Rammurthy Banothu,
  • Murali Boosa and
  • Narender Nama

Beilstein J. Org. Chem. 2020, 16, 3093–3103, doi:10.3762/bjoc.16.259

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  • moderate to excellent yields. This draws the conclusion that the benzylic C–H unit of 2-alkylpyridine/quinolines actively participates in this addition reaction. However, in some cases, 2-alkenyl compounds were formed. Nevertheless, these are of equivalent significance. Moreover, this method has a high
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Published 23 Dec 2020

Using multiple self-sorting for switching functions in discrete multicomponent systems

  • Amit Ghosh and
  • Michael Schmittel

Beilstein J. Org. Chem. 2020, 16, 2831–2853, doi:10.3762/bjoc.16.233

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  • activity in a Knoevenagel addition reaction. At the same time, the click reaction remained shut down (ON-1, OFF-2). In sum, the three interdependent states SelfSORT-I to III regulated two different reaction outcomes and an OFF state. In biology, motor proteins carry out essential tasks by walking along
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Published 20 Nov 2020

Asymmetric Mannich reactions of (S)-N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimines with yne nucleophiles

  • Ziyi Li,
  • Li Wang,
  • Yunqi Huang,
  • Haibo Mei,
  • Hiroyuki Konno,
  • Hiroki Moriwaki,
  • Vadim A. Soloshonok and
  • Jianlin Han

Beilstein J. Org. Chem. 2020, 16, 2671–2678, doi:10.3762/bjoc.16.217

Graphical Abstract
  • yields and high enantioselectivities by the groups of Zhou and Peng, respectively (Scheme 1a). It should be mentioned that the Qing group also reported a method for the synthesis of α-trifluoromethylated α-propargylamines via a Ti-promoted addition reaction between acetylide and chiral CF3-ketimines
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Published 29 Oct 2020

Catalytic trifluoromethylation of iodoarenes by use of 2-trifluoromethylated benzimidazoline as trifluoromethylating reagent

  • Tatsuhiro Uchikura,
  • Nanami Kamiyama,
  • Taisuke Ishikawa and
  • Takahiko Akiyama

Beilstein J. Org. Chem. 2020, 16, 2442–2447, doi:10.3762/bjoc.16.198

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  • (I)–CF3 species, generated through the reaction of benzimidazoline 2 with CuI under basic conditions, underwent an oxidative addition reaction with the aryl iodide to generate a Cu(III) complex. A subsequent reductive elimination furnished the trifluoromethylarene and Cu(I). Because an electron
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Published 30 Sep 2020

Recent developments in enantioselective photocatalysis

  • Callum Prentice,
  • James Morrisson,
  • Andrew D. Smith and
  • Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

Graphical Abstract
  • synthesise the corresponding RCA products 283 in excellent yields and enantioselectivities (22 examples, up to >99:1 er) (Scheme 45) [111]. Huang et al. applied a similar catalytic system to that reported by Yoon et al. to a different radical addition reaction between nitrones 284 and aldehydes 285 (Scheme
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Published 29 Sep 2020

A complementary approach to conjugated N-acyliminium formation through photoredox-catalyzed intermolecular radical addition to allenamides and allencarbamates

  • Olusesan K. Koleoso,
  • Matthew Turner,
  • Felix Plasser and
  • Marc C. Kimber

Beilstein J. Org. Chem. 2020, 16, 1983–1990, doi:10.3762/bjoc.16.165

Graphical Abstract
  • undergoes an addition reaction with a suitable nucleophile (Scheme 1). Importantly, the electrophilic mediated formation of this key intermediate 2 have been the cornerstone for allenamide chemistry over the past 15 years. Therefore, given the importance of the allenamide building block we sought a new
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Published 12 Aug 2020

Pauson–Khand reaction of fluorinated compounds

  • Jorge Escorihuela,
  • Daniel M. Sedgwick,
  • Alberto Llobat,
  • Mercedes Medio-Simón,
  • Pablo Barrio and
  • Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

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  • this sense, while the addition of hard organometallic nucleophiles, such as lithium dialkylcuprates or Grignard reagents, failed, softer nucleophiles such as nitroalkanes cleanly added to the β-position, providing the Michael adduct 61. Unexpectedly, the conjugate addition reaction resulted in
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Published 14 Jul 2020

The McKenna reaction – avoiding side reactions in phosphonate deprotection

  • Katarzyna Justyna,
  • Joanna Małolepsza,
  • Damian Kusy,
  • Waldemar Maniukiewicz and
  • Katarzyna M. Błażewska

Beilstein J. Org. Chem. 2020, 16, 1436–1446, doi:10.3762/bjoc.16.119

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  • storage and/or use of BTMS, which exposes it to traces of water. As mentioned in the previous section, compounds having multiple bonds could undergo an addition reaction upon exposure to HBr [42]. We studied this problem using 1H NMR spectroscopy with the model acrylamide 11 (Scheme 3), representing a
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Published 23 Jun 2020

An overview on disulfide-catalyzed and -cocatalyzed photoreactions

  • Yeersen Patehebieke

Beilstein J. Org. Chem. 2020, 16, 1418–1435, doi:10.3762/bjoc.16.118

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  • fluorine-containing groups can effectively change the physical and chemical properties and biological activities of organic molecules [21][22]. The addition reaction using disulfide as the visible-light catalyst is an effective and atom-economic method for introducing fluorine-containing groups. In 2016
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Published 23 Jun 2020

Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel–Hauser amides, and magnesium alkoxides

  • Mateo Berton,
  • Kevin Sheehan,
  • Andrea Adamo and
  • D. Tyler McQuade

Beilstein J. Org. Chem. 2020, 16, 1343–1356, doi:10.3762/bjoc.16.115

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  • possible to directly use the hygroscopic LiCl in a solid form. The back-pressure control allows a high-temperature oxidative addition reaction and enables the quantitative conversion of less reactive but more cost-effective alkyl chlorides. Furthermore, a low-cost pod-style synthesizer prototype has been
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Published 19 Jun 2020
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