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Search for "metal catalyst" in Full Text gives 124 result(s) in Beilstein Journal of Organic Chemistry.

Functionalization of N-arylglycine esters: electrocatalytic access to C–C bonds mediated by n-Bu4NI

  • Mi-Hai Luo,
  • Yang-Ye Jiang,
  • Kun Xu,
  • Yong-Guo Liu,
  • Bao-Guo Sun and
  • Cheng-Chu Zeng

Beilstein J. Org. Chem. 2018, 14, 499–505, doi:10.3762/bjoc.14.35

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  • transition metal catalyst Cu(OTf)2, Wu and co-workers achieved aerobic oxidative coupling of secondary amines with β-keto esters to form C(sp3)–C(sp3) bonds (Scheme 1) [18]. Although much advance has been made for the functionalization of glycine derivatives, most of these strategies mentioned above require
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Published 22 Feb 2018

Photocatalytic formation of carbon–sulfur bonds

  • Alexander Wimmer and
  • Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

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  • -dicyanobenzene) as organic photoredox catalyst and [NiCl2·dme] as transition metal catalyst in a continuous flow set-up, high yields of the coupling products were obtained in short residence times (30 min). They propose, that photoexcited 4CzIPN* generates the thiyl radical, which adds to the [NiI] complex
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Published 05 Jan 2018

CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF3SO2Na

  • Hélène Guyon,
  • Hélène Chachignon and
  • Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

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  • result of electron paramagnetic resonance spectroscopy experiments (Scheme 50). In 2016, Li, Mi and co-workers reported a simple and clean approach for the direct trifluoromethylation of unactivated arenes and heteroarenes through a photoreduction without any metal catalyst nor oxidant. The radical
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Published 19 Dec 2017

Transition-metal-free synthesis of 3-sulfenylated chromones via KIO3-catalyzed radical C(sp2)–H sulfenylation

  • Yanhui Guo,
  • Shanshan Zhong,
  • Li Wei and
  • Jie-Ping Wan

Beilstein J. Org. Chem. 2017, 13, 2017–2022, doi:10.3762/bjoc.13.199

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  • protocol toward these compounds through the tandem reactions between o-hydroxyphenylenaminones and sulfonyl hydrazines. In this method, the construction of the target products is furnished via the key C–H sulfenylation without using any transition metal catalyst or oxidative additive. Results and
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Published 27 Sep 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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  • example, a) at higher frequency (800 min−1) for 45 min lower yield with less selectivity was observed and b) using lower frequency, 200 min−1 for 8 h led to 82% of yield with high selectivity. In the traditional method of pyran synthesis the use of transition metal catalyst, corrosive acid, longer
  • the metal catalyst from rhodium to iridium. In 2016, using an Ir(III) catalyst an unprecedented ortho-selective Csp2–H bond amidation of benzamides with sulfonyl azides as the amide source was done under solvent-free ball mill conditions (Scheme 51) [183]. They could also isolate cyclic iridium
  • . It allows selective functionalization of C–H bonds to C–hetero atoms as discussed herein. Moreover, the major drawbacks are involvement of harsh reaction conditions like high temperature, longer reaction time, and huge amount of toxic organic solvents and handling of sensitive metal catalyst. But
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Published 11 Sep 2017

2-Methyl-2,4-pentanediol (MPD) boosts as detergent-substitute the performance of ß-barrel hybrid catalyst for phenylacetylene polymerization

  • Julia Kinzel,
  • Daniel F. Sauer,
  • Marco Bocola,
  • Marcus Arlt,
  • Tayebeh Mirzaei Garakani,
  • Andreas Thiel,
  • Klaus Beckerle,
  • Tino Polen,
  • Jun Okuda and
  • Ulrich Schwaneberg

Beilstein J. Org. Chem. 2017, 13, 1498–1506, doi:10.3762/bjoc.13.148

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  • protein FhuA; Introduction The combination of a transition metal catalyst and a protein by either dative, supramolecular or covalent means leads to so-called artificial metalloenzymes or biohybrid catalysts [1][2]. Using a non-natural catalyst, the scope of natural enzymes can be expanded or the activity
  • analyzed by MALDI–TOF mass spectrometry prior to digestion of 2 with the protease of the Tobacco Etch Virus (TEV) [29][47][49]. Even though the calculated mass of 6,301 Da for the FhuA ΔCVFtev fragment containing Cys545 and the metal catalyst (≈6 kDa) could not be observed, the MALDI–TOF mass spectra
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Published 31 Jul 2017

Detection of therapeutic radiation in three-dimensions

  • John A. Adamovics

Beilstein J. Org. Chem. 2017, 13, 1325–1331, doi:10.3762/bjoc.13.129

Graphical Abstract
  • diisocyanate (IPDI) [47]. The polymerization reaction is exothermic and the rate of curing is dependent on the temperature, concentration of reactive groups, total volume of the reactants and type and concentration of metal catalyst. A number of metals have been studied in the polymer reaction but the most
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Published 05 Jul 2017

Strategies toward protecting group-free glycosylation through selective activation of the anomeric center

  • A. Michael Downey and
  • Michal Hocek

Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123

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  • without any glycosylation taking place. To our knowledge, this study provides the first example of a metal-catalyzed glycosylation reaction in the presence of free hydroxy groups. The authors postulated that the reaction proceeds through the formation of a π-complex between the alkyne and the metal
  • catalyst [63]. They also determined that MeCN was the most suitable solvent which means that coordination of the ligands to the catalyst is important for progression of the reaction and that if the saccharide donor is acetylated, the reaction does not proceed. It should be emphasized that the reaction
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Published 27 Jun 2017

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

  • Carmen Moreno-Marrodan,
  • Francesca Liguori and
  • Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

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  • different variables, i.e., the metal catalyst involved, the type of support material, the reactor design or the hydrogen source. We decided to break down the manuscript on the basis of the substrates examined in order to allow an easier comparison among different reactors performance and highlight the
  • . Selectivity in partial hydrogenation is ruled by the relative rates of the first and second hydrogenation steps, as well as by the adsorption strengths of alkyne and alkene over the metal catalyst surface. Other side-products may include those due to dimerization and isomerization reactions, depending on the
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Published 20 Apr 2017

Effect of the ortho-hydroxy group of salicylaldehyde in the A3 coupling reaction: A metal-catalyst-free synthesis of propargylamine

  • Sujit Ghosh,
  • Kinkar Biswas,
  • Suchandra Bhattacharya,
  • Pranab Ghosh and
  • Basudeb Basu

Beilstein J. Org. Chem. 2017, 13, 552–557, doi:10.3762/bjoc.13.53

Graphical Abstract
  • invented an unprecedented effect of salicylaldehyde, one of the A3 coupling partners, which could lead to the formation of propargylamine, an important pharmaceutical building block, in the absence of any metal catalyst and under mild conditions. The role of the hydroxy group in ortho position of
  • salicylaldehyde has been explored, which presumably activates the Csp–H bond of the terminal alkyne leading to the formation of propargylamines in good to excellent yields, thus negating the function of the metal catalyst. This observation is hitherto unknown, tested for a variety of salicylaldehyde, amine and
  • acetylene, established as a general protocol, and is believed to be of interest for synthetic chemists from green chemistry. Keywords: A3 coupling; metal-catalyst-free; propargylamine; salicylaldehyde; terminal alkyne; Introduction Propargylamines are important synthetic intermediates for the preparation
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Published 16 Mar 2017

β-Amino functionalization of cinnamic Weinreb amides in ionic liquid

  • Yi-Ning Wang,
  • Guo-Xiang Sun and
  • Gang Qi

Beilstein J. Org. Chem. 2016, 12, 2372–2377, doi:10.3762/bjoc.12.231

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  • as the nitrogen source and Cu(I)OTf as the metal catalyst [33][34]. However, there no aminochlorination products were observed. Next, we turned our attention to the use of ionic liquids, which have shown many significant advantages in the reported aminochlorination reactions [35][36][37]. However
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Published 11 Nov 2016

Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene with alcohols

  • Katrina Tait,
  • Oday Alrifai,
  • Rebecca Boutin,
  • Jamie Haner and
  • William Tam

Beilstein J. Org. Chem. 2016, 12, 2189–2196, doi:10.3762/bjoc.12.209

Graphical Abstract
  • substituted and complex organic frameworks (Scheme 1) [3][4][5][6][7][8][9][10][11][12][13]. An important chemical transformation is the nucleophilic ring opening of oxabicyclic alkene 1, which offers a diverse collection of dihydronaphthalenols depending on the metal catalyst and nucleophiles used (Scheme 2
  • type of ring-opening pathway it follows. This complements previous studies by our group involving the ring opening of cyclopropanated oxabenzonorbornadiene through the novel use of a transition metal catalyst. Using a transition metal catalyst could reveal new ring-opening pathways and provide further
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Published 14 Oct 2016

Synthesis of β-arylated alkylamides via Pd-catalyzed one-pot installation of a directing group and C(sp3)–H arylation

  • Yunyun Liu,
  • Yi Zhang,
  • Xiaoji Cao and
  • Jie-Ping Wan

Beilstein J. Org. Chem. 2016, 12, 1122–1126, doi:10.3762/bjoc.12.108

Graphical Abstract
  • incorporation of a metal catalyst and controlling the site selectivity [7][8][9]. While benefiting the advantage of straightforward transformation from the C–H activation strategy, the utilization of a DG also brings unfavorable defection of step economics because an additional operation step in installing the
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Published 03 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

Graphical Abstract
  • imines, carbonyls or allene homologs. The resulting homologated nucleophile 8 may then be trapped in an intramolecular fashion by a π-allyl complex, which may concomitantly form from 6 through activation of the homoallylic functionality with a suitable transition metal catalyst. According to this concept
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Published 02 Jun 2016

Cationic Pd(II)-catalyzed C–H activation/cross-coupling reactions at room temperature: synthetic and mechanistic studies

  • Takashi Nishikata,
  • Alexander R. Abela,
  • Shenlin Huang and
  • Bruce H. Lipshutz

Beilstein J. Org. Chem. 2016, 12, 1040–1064, doi:10.3762/bjoc.12.99

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  • ][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71], has been found to profoundly impact reactivity; (3) tuning of ligands around the transition metal catalyst center has emerged as an especially powerful
  • means of enhancing and controlling reactivity in these processes [95][96][97][98][99][100][101][102][103][104][105][106][107]. A fourth approach with considerable potential, and which appears to have received considerably less attention, involves tuning the cationicity of the transition metal catalyst
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Published 20 May 2016

Copper-mediated arylation with arylboronic acids: Facile and modular synthesis of triarylmethanes

  • H. Surya Prakash Rao and
  • A. Veera Bhadra Rao

Beilstein J. Org. Chem. 2016, 12, 496–504, doi:10.3762/bjoc.12.49

Graphical Abstract
  • report a copper(II) triflate-catalyzed modular synthesis of triarylmethanes by employing diarylmethanols 9 and arylboronic acids 10. It is advantageous to employ a base metal catalyst such as copper(II) triflate instead of palladium [55][56] or nickel (Ni) [57] catalysts and to avoid the use of phosphine
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Published 11 Mar 2016

Easy access to heterobimetallic complexes for medical imaging applications via microwave-enhanced cycloaddition

  • Nicolas Desbois,
  • Sandrine Pacquelet,
  • Adrien Dubois,
  • Clément Michelin and
  • Claude P. Gros

Beilstein J. Org. Chem. 2015, 11, 2202–2208, doi:10.3762/bjoc.11.239

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  • convenient and rapid access to bimetallic building blocks, opening the door for a wide range of applications in medical imaging. In some cases, the requirement of a metal catalyst can be a complication. Therefore, we actually focus our researches on the development of catalyst-free click reactions using, e.g
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Published 17 Nov 2015

Synthesis of γ-hydroxypropyl P-chirogenic (±)-phosphorus oxide derivatives by regioselective ring-opening of oxaphospholane 2-oxide precursors

  • Iris Binyamin,
  • Shoval Meidan-Shani and
  • Nissan Ashkenazi

Beilstein J. Org. Chem. 2015, 11, 1332–1339, doi:10.3762/bjoc.11.143

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  • fact that the γ-hydroxypropyl substituent, which results directly from the ring opening of the phospholane, could provide a second ligation site upon complexation of the corresponding phosphines to a transition metal catalyst. These P,O bidentate ligands are quite useful in organometallic compounds
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Published 30 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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  • delivers the desired 1,4-triazole regioisomer without the need for a metal catalyst that requires stringent purification afterwards. Due to the reduced reactivity of 100 the crucial cycloaddition step was conducted neat at elevated temperature (210 °C) yielding pure 102 within short residence times (5–30
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Published 17 Jul 2015

Stereoselective cathodic synthesis of 8-substituted (1R,3R,4S)-menthylamines

  • Carolin Edinger,
  • Jörn Kulisch and
  • Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2015, 11, 294–301, doi:10.3762/bjoc.11.34

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  • the configuration at position 4 resulting in a complex diastereomeric mixture. Alternatively, reduction of menthone oxime can be achieved, either employing Bouveault–Blanc conditions [41], or via hydrogenolysis at a transition metal catalyst [42]. Both approaches lead to the desired product as a
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Published 27 Feb 2015

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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  • -substituted on the phenyl side-rings by a large variety of substituents, as well as stereo- and regioselectivity (particularly for the bulky groups). Nevertheless, due to the most common metal catalyst (palladium) this method is significantly more expensive and less environmentally friendly than radical-based
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Published 10 Dec 2014

Exploration of C–H and N–H-bond functionalization towards 1-(1,2-diarylindol-3-yl)tetrahydroisoquinolines

  • Michael Ghobrial,
  • Marko D. Mihovilovic and
  • Michael Schnürch

Beilstein J. Org. Chem. 2014, 10, 2186–2199, doi:10.3762/bjoc.10.226

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  • catalyst instead of copper since palladium has been widely recognized as powerful transition metal catalyst involved in C2-arylations of azoles [25][33][46][47][55][56][57][58]. C2-Arylation of 1-(indol-3-yl)-N-PG-THIQs 4 was expected to be challenging since the C3 position of the indole is blocked by the
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Published 15 Sep 2014

P(O)R2-directed Pd-catalyzed C–H functionalization of biaryl derivatives to synthesize chiral phosphorous ligands

  • Rong-Bin Hu,
  • Hong-Li Wang,
  • Hong-Yu Zhang,
  • Heng Zhang,
  • Yan-Na Ma and
  • Shang-dong Yang

Beilstein J. Org. Chem. 2014, 10, 2071–2076, doi:10.3762/bjoc.10.215

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  • ]. In particular, their special effects of enhancing the metal-catalyst efficiency and of controlling chiral induction has continually prompted synthetic chemists to probe efficient methods generating access to chiral, enantiomerically pure phosphorus compounds used in pharmaceutical, agrochemical and
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Published 02 Sep 2014

Preparation of phosphines through C–P bond formation

  • Iris Wauters,
  • Wouter Debrouwer and
  • Christian V. Stevens

Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106

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  • papers appeared reporting on organocatalyzed asymmetric hydrophosphinations. The organocatalytic process has the advantage that in contrast to a metal-catalyzed method, it cannot undergo product inhibition as a result of the coordination ability of phosphorus to a metal catalyst. The addition of
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Published 09 May 2014

Silver and gold-catalyzed multicomponent reactions

  • Giorgio Abbiati and
  • Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

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  • great chemical diversity of the products of MCRs. Moreover, imines can participate in MCRs as electrophilic or nucleophilic partners, azadienes, dienophiles and 1,3-dipoles. All these reactions may benefit from the presence of a Lewis acid, a Brønsted acid or a transition metal catalyst. Silver
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Published 26 Feb 2014
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