Search results

Search for "dehydrogenation" in Full Text gives 95 result(s) in Beilstein Journal of Organic Chemistry.

Efficient N-arylation of 4-chloroquinazolines en route to novel 4-anilinoquinazolines as potential anticancer agents

  • Rodolfo H. V. Nishimura,
  • Thiago dos Santos,
  • Valter E. Murie,
  • Luciana C. Furtado,
  • Leticia V. Costa-Lotufo and
  • Giuliano C. Clososki

Beilstein J. Org. Chem. 2021, 17, 2968–2975, doi:10.3762/bjoc.17.206

Graphical Abstract
  • that, the cyclocondensation [29] of the halogenated anthranilamides 6a,b with benzaldehyde followed by dehydrogenation promoted by iodine gave the corresponding quinazolin-4(3H)-ones 7a,b, which we used in the next step without purification. Finally, chlorination [31] of quinazolin-4(3H)-ones 7a,b by
PDF
Album
Supp Info
Full Research Paper
Published 22 Dec 2021

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

  • Alemayehu Gashaw Woldegiorgis and
  • Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

Graphical Abstract
  • accelerating imine formation (I-19), and under the catalysis of a chiral phosphoric acid, intramolecular nucleophilic addition occurs to form I-20, followed by oxidative dehydrogenation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). In the presence of 10 mol % chiral phosphoric acid CPA 7, the axially
PDF
Album
Review
Published 15 Nov 2021

Electrocatalytic C(sp3)–H/C(sp)–H cross-coupling in continuous flow through TEMPO/copper relay catalysis

  • Bin Guo and
  • Hai-Chao Xu

Beilstein J. Org. Chem. 2021, 17, 2650–2656, doi:10.3762/bjoc.17.178

Graphical Abstract
  • through reversible reaction with this cationic species. Conclusion In summary, we have achieved the electrochemical dehydrogenation cross-coupling of tetrahydroisoquinolines with terminal alkynes in continuous flow through Cu/TEMPO relay catalysis. This work demonstrates that continuous-flow
PDF
Album
Supp Info
Letter
Published 28 Oct 2021

Synthesis of new bile acid-fused tetrazoles using the Schmidt reaction

  • Dušan Đ. Škorić,
  • Olivera R. Klisurić,
  • Dimitar S. Jakimov,
  • Marija N. Sakač and
  • János J. Csanádi

Beilstein J. Org. Chem. 2021, 17, 2611–2620, doi:10.3762/bjoc.17.174

Graphical Abstract
  • selective acetylation [43], followed by oxidation. Enones 4 and 8 were prepared by dehydrogenation of corresponding ketones with SeO2 in refluxing acetic acid [44]. Microwave-assisted heating of the reaction mixture in a closed vessel (150 °C) helped in decreasing the reaction time for dehydrogenation
PDF
Album
Supp Info
Full Research Paper
Published 20 Oct 2021

Efficient synthesis of polyfunctionalized carbazoles and pyrrolo[3,4-c]carbazoles via domino Diels–Alder reaction

  • Ren-Jie Fang,
  • Chen Yan,
  • Jing Sun,
  • Ying Han and
  • Chao-Guo Yan

Beilstein J. Org. Chem. 2021, 17, 2425–2432, doi:10.3762/bjoc.17.159

Graphical Abstract
  • benzylideneacetone in acetonitrile in the presence of p-TsOH and DDQ resulted in polyfunctionalized carbazoles in satisfactory yields. The reaction mechanism included the DDQ oxidative dehydrogenation of 3-(indol-3-yl)-1,3-diphenylpropan-1-ones to the corresponding 3-vinylindoles, their acid-catalyzed Diels–Alder
  • dehydrogenation reaction was carried out in acetonitrile at room temperature. A series of aromatized pyrrolo[3,4-c]carbazoles 4a–l were successfully synthesized by the one-pot two-step reaction and the results are summarized in Table 1. All reactions proceeded smoothly to give the corresponding pyrrolo[3,4-c
  • active diene, indole-substituted chalcones. Then, the p-TsOH-catalyzed Diels–Alder reaction of indole-chalcones with second chalcones and sequential aromatization through DDQ dehydrogenation resulted in the polyfunctionalized carbazoles 6a–l in good yields (Table 2). Additionally, the similar reaction
PDF
Album
Supp Info
Full Research Paper
Published 16 Sep 2021

Breaking paracyclophane: the unexpected formation of non-symmetric disubstituted nitro[2.2]metaparacyclophanes

  • Suraj Patel,
  • Tyson N. Dais,
  • Paul G. Plieger and
  • Gareth J. Rowlands

Beilstein J. Org. Chem. 2021, 17, 1518–1526, doi:10.3762/bjoc.17.109

Graphical Abstract
  • highly oxidizing conditions, dehydrogenation of the resulting cyclohexadienol would give 11.The electron-rich 4-hydroxy[2.2]metaparacyclophane (9) participates in ortho selective nitration to give 5. Nitric acid has previously been used to oxidize phenols to cyclohexadienones [69][70], and a plausible
PDF
Album
Supp Info
Full Research Paper
Published 29 Jun 2021

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

  • Joseane A. Mendes,
  • Paulo R. R. Costa,
  • Miguel Yus,
  • Francisco Foubelo and
  • Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

Graphical Abstract
PDF
Album
Review
Published 12 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
  • dehydration forms D and finally 12. The synthesized naphthoacridines 12 with 2,3-diaminonaphthalene produces 14 via dehydration and dehydrogenation. 2 Azepines Azepines are represented by unsaturated seven atom heterocyles with nitrogen replacing a carbon atom. The benzene-fused azepines known as
PDF
Album
Review
Published 19 Apr 2021

[2 + 1] Cycloaddition reactions of fullerene C60 based on diazo compounds

  • Yuliya N. Biglova

Beilstein J. Org. Chem. 2021, 17, 630–670, doi:10.3762/bjoc.17.55

Graphical Abstract
  • . Catalysis is the next area that is gaining an ever-increasing practical focus in the studies on the use of C60 and fullerene-containing materials [51]. A comparative analysis of the activity of fullerene-containing compounds and noble metals as dehydrogenation catalysts allows to consider the former as
  • the substrate on two sites, namely a metal and a fullerene [53]. This allows to level out some negative features that are characteristic of heterogeneous catalysts. Thus, in dehydrogenation processes, catalytic amounts of a coordinated fullerene in metal fullerides act as a hydrogen acceptor in
PDF
Review
Published 05 Mar 2021

Biochemistry of fluoroprolines: the prospect of making fluorine a bioelement

  • Vladimir Kubyshkin,
  • Rebecca Davis and
  • Nediljko Budisa

Beilstein J. Org. Chem. 2021, 17, 439–460, doi:10.3762/bjoc.17.40

Graphical Abstract
  • entry into the citric acid cycle. The dehydrogenation of proline is involved in numerous biochemical processes. For example, the dehydrogenation of proline linked to an acyl carrier protein makes a first step in the biosynthesis of some neurotoxins from cyanobacteria (ana gene cluster) [68]. The
PDF
Album
Review
Published 15 Feb 2021

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

  • Minzan Zuo,
  • Krishnasamy Velmurugan,
  • Kaiya Wang,
  • Xueqi Tian and
  • Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

Graphical Abstract
  • between thiol-functionalized β-CD and oleic acid-protected CdS nanocrystals [29]. These spherical CdS–CD nanoparticles could be employed as a photocatalyst for the dehydrogenation of alcohols to aldehydes (at a low concentration of the reactant of 1 mM, ≥92% selectivity) or diols (at a high concentration
  • of the reactant of 300 mM, ≥93% selectivity), with H2 liberation being achieved by visible-light irradiation in an aqueous solution. In comparison, CdS–CD was a highly efficient photocatalyst for benzyl alcohol dehydrogenation (77 µmol H2 in 180 h) compared to the CD-free CdS (5.4 µmol H2 in 30 h
PDF
Album
Review
Published 18 Jan 2021

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

  • Shakeel Alvi and
  • Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

Graphical Abstract
  • ′-tetramethylethylenediamine (TMEDA) as shown in the Scheme 1. Having the compound 4 in hand, it was subjected to the cyclization in the presence of boron trifluoride to provide the tricyclohexyl-fused benzene derivative which on further dehydrogenation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) afforded 1,5,9
PDF
Album
Review
Published 09 Sep 2020

Reactions of 3-aryl-1-(trifluoromethyl)prop-2-yn-1-iminium salts with 1,3-dienes and styrenes

  • Thomas Schneider,
  • Michael Keim,
  • Bianca Seitz and
  • Gerhard Maas

Beilstein J. Org. Chem. 2020, 16, 2064–2072, doi:10.3762/bjoc.16.173

Graphical Abstract
  • good yield. Dehydrogenation of 7 with chloranil then provided 9-(dimethylamino)-9-(trifluoromethyl)fluorene 8. In an analogous reaction sequence, 11H-benzo[a]fluorene derivative 9 was obtained from 3-(2-naphthyl)propyn-1-iminium salt 1b and 2,3-dimethylbutadiene (Scheme 2) in a one-pot three-step
PDF
Album
Supp Info
Full Research Paper
Published 24 Aug 2020

Heterogeneous photocatalysis in flow chemical reactors

  • Christopher G. Thomson,
  • Ai-Lan Lee and
  • Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

Graphical Abstract
PDF
Album
Review
Published 26 Jun 2020

Oxime radicals: generation, properties and application in organic synthesis

  • Igor B. Krylov,
  • Stanislav A. Paveliev,
  • Alexander S. Budnikov and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

Graphical Abstract
  • dehydrogenation of the side chain attached to C=NO fragment was observed. Under the action of the TMSCF3/trichloroisocyanuric acid/TCCA/CuOAc/CsF system β,γ-unsaturated oximes 146 undergo oxidative cyclization to form substituted isoxazolines 147 with a trifluoromethyl group (Scheme 49) [138]. The authors note
PDF
Album
Review
Published 05 Jun 2020

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

  • Stephanie G. E. Amos,
  • Marion Garreau,
  • Luca Buzzetti and
  • Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

Graphical Abstract
  • oxidation of 29.1 was achieved using Mes-Acr-Me+ (OD2) and a cobalt cocatalyst, ensuring an efficient dehydrogenation. Various N-heterocycles 29.3 were accessed via a radical cyclization cascade with the alkyne derivatives 29.2. Amidyl radical generation The oxidation of amides is more difficult compared to
PDF
Album
Review
Published 29 May 2020

Copper catalysis with redox-active ligands

  • Agnideep Das,
  • Yufeng Ren,
  • Cheriehan Hessin and
  • Marine Desage-El Murr

Beilstein J. Org. Chem. 2020, 16, 858–870, doi:10.3762/bjoc.16.77

Graphical Abstract
  • x increases with the removal of electrons). On the other hand, complex t-BuPhCuO.S.2, showing a reversible oxidation behavior very efficiently performs dehydrogenation of benzyl alcohol with low catalyst loading (0.1 mol %) and high turnover numbers (TONs up to 184). Besides the oxidation of benzyl
PDF
Album
Review
Published 24 Apr 2020

Synthesis of 3-alkenylindoles through regioselective C–H alkenylation of indoles by a ruthenium nanocatalyst

  • Abhijit Paul,
  • Debnath Chatterjee,
  • Srirupa Banerjee and
  • Somnath Yadav

Beilstein J. Org. Chem. 2020, 16, 140–148, doi:10.3762/bjoc.16.16

Graphical Abstract
  • oxidative dehydrogenation [19]. Recently, Maji and co-workers reported the synthesis of 3-alkenylindoles from indoles and α-hydrogen-containing alkyl-/arylaldehydes by successive Brønsted acid/base catalysis (Scheme 1) [20]. The third category, which is also the most explored and popular one, involves the
PDF
Album
Supp Info
Full Research Paper
Published 29 Jan 2020

Construction of trisubstituted chromone skeletons carrying electron-withdrawing groups via PhIO-mediated dehydrogenation and its application to the synthesis of frutinone A

  • Qiao Li,
  • Chen Zhuang,
  • Donghua Wang,
  • Wei Zhang,
  • Rongxuan Jia,
  • Fengxia Sun,
  • Yilin Zhang and
  • Yunfei Du

Beilstein J. Org. Chem. 2019, 15, 2958–2965, doi:10.3762/bjoc.15.291

Graphical Abstract
  • biologically interesting chromone skeleton was realized by PhIO-mediated dehydrogenation of chromanones under mild conditions. Interestingly, this method also found application in the synthesis of the naturally occurring frutinone A. Keywords: chromanone; chromone; dehydrogenation; frutinone A; PhIO
  • highly efficient method for the synthesis of this privileged class of heterocycles. For example, Kim and co-workers reported that chromones could be prepared via a Pd(II)-catalyzed [55][56][57] dehydrogenation of chromanone derivatives at 100 °C in DMSO (Scheme 1a) [58]. The synthesis of chromones could
  • also be realized by DDQ-mediated dehydrogenation of chromanones under heating in dioxane (Scheme 1b) [3][59][60]. In 2005, Yang and co-workers reported that chromones could be formed by microwave irradiation of the corresponding chromanone reactants and N-bromosuccinimide (NBS) in the presence of a
PDF
Album
Supp Info
Letter
Published 12 Dec 2019

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

  • Xiaowei Li,
  • Xiaolin Shi,
  • Xiangqian Li and
  • Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

Graphical Abstract
  • dehydrogenation process to afford the target product. Also in 2015, Li and co-workers [146] developed a mild and fast Cu(I/II)-catalyzed trifluoromethylation procedure to obtain 3-trifluoromethylcoumarins. The reaction was carried out with a CuCl/CF3SO2Na/TBHP system under continuous-flow conditions, affording
PDF
Album
Review
Published 23 Sep 2019

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

  • Gagandeep Kour Reen,
  • Ashok Kumar and
  • Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Graphical Abstract
  • well, giving the corresponding products in excellent yields. This protocol served as a novel route for the synthesis of imidazo[1,5-a]pyridines 37 via oxidative amination of sp3 C–H bonds in the aerial atmosphere. The reaction involved oxidative dehydrogenation of benzylamine intermediate 92 to form 93
  • which underwent resonance to give 94. This was followed by intramolecular amination, oxidative dehydrogenation, and rearrangement to yield the final product 37 (Scheme 31). A one-pot, tandem reaction promoted by a I2/CuO system to synthesize imidazo[1,2-a]pyridines was reported by Cai et al. (Scheme 32
PDF
Album
Review
Published 19 Jul 2019

A heteroditopic macrocycle as organocatalytic nanoreactor for pyrroloacridinone synthesis in water

  • Piyali Sarkar,
  • Sayan Sarkar and
  • Pradyut Ghosh

Beilstein J. Org. Chem. 2019, 15, 1505–1514, doi:10.3762/bjoc.15.152

Graphical Abstract
  • [2,3,4-kl]acridinones in high yields and illustrated the adaptability of this protocol (Scheme 2). Thus, under the above optimized conditions, the corresponding fully oxidized products were obtained through aerial oxidation or dehydrogenation of 4,5-dihydropyrrolo[2,3,4-kl]acridinones driven by aromatic
PDF
Album
Supp Info
Full Research Paper
Published 08 Jul 2019

Aqueous olefin metathesis: recent developments and applications

  • Valerio Sabatino and
  • Thomas R. Ward

Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39

Graphical Abstract
  • water is more likely to occur at high temperatures and in the presence of a base. 1H NMR studies revealed that methanol is the source of hydride and this was later confirmed by Grubbs and co-workers [31]. The proposed mechanism for the degradation of G-I occurs via alcohol dehydrogenation followed by
PDF
Album
Review
Published 14 Feb 2019

Oxidative radical ring-opening/cyclization of cyclopropane derivatives

  • Yu Liu,
  • Qiao-Lin Wang,
  • Zan Chen,
  • Cong-Shan Zhou,
  • Bi-Quan Xiong,
  • Pan-Liang Zhang,
  • Chang-An Yang and
  • Quan Zhou

Beilstein J. Org. Chem. 2019, 15, 256–278, doi:10.3762/bjoc.15.23

Graphical Abstract
  • , phenylselenyl radical 26 was produced in the presence of free radical initiator (NH4)2S2O8 [60][61]. Next, the intermediate 26 was added to the C–C double bond of MCPs 23, and then went through a series of ring-opening, intramolecular cyclization, oxidation and dehydrogenation to generate 3
  • -opening, cyclization, oxidation and dehydrogenation and successfully furnished trifluoromethylthiolated 1,2-dihydronaphthalene derivatives 39 (Scheme 10) [67]. This reaction was achieved in the presence of 3.0 equiv of Na2S2O8 as the oxidants, 0.5 equiv of HMPA (N,N,N',N',N'',N
  • addition of radical 44 to the C–C double bond of MCPs 1 generats a more stable benzyl radical 45. Final ring-opening, intramolecular cyclization, oxidation, and dehydrogenation finally delivers the desired product 41. Next, our group reported the first oxidative ring-opening and cyclization between MCPs 1
PDF
Album
Review
Published 28 Jan 2019

First thia-Diels–Alder reactions of thiochalcones with 1,4-quinones

  • Grzegorz Mlostoń,
  • Katarzyna Urbaniak,
  • Paweł Urbaniak,
  • Anna Marko,
  • Anthony Linden and
  • Heinz Heimgartner

Beilstein J. Org. Chem. 2018, 14, 1834–1839, doi:10.3762/bjoc.14.156

Graphical Abstract
  • Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland 10.3762/bjoc.14.156 Abstract Aryl and hetaryl thiochalcones react smoothly with 1,4-quinones in THF solution at 60 °C yielding the corresponding fused 4H-thiopyrans after spontaneous dehydrogenation of the
PDF
Album
Supp Info
Full Research Paper
Published 19 Jul 2018
Other Beilstein-Institut Open Science Activities