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Search for "catalytic reaction" in Full Text gives 90 result(s) in Beilstein Journal of Organic Chemistry.

Contribution of microreactor technology and flow chemistry to the development of green and sustainable synthesis

  • Flavio Fanelli,
  • Giovanna Parisi,
  • Leonardo Degennaro and
  • Renzo Luisi

Beilstein J. Org. Chem. 2017, 13, 520–542, doi:10.3762/bjoc.13.51

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  • ]. Contribution of continuous-flow metal-, organo-, and photocatalysis in green chemistry The development of continuous-flow catalysis is appealing because it combines the advantages of a catalytic reaction with the benefits of flow microreactors. Under homogeneous conditions a soluble catalyst, which flows
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Published 14 Mar 2017

Synthesis of 1-indanones with a broad range of biological activity

  • Marika Turek,
  • Dorota Szczęsna,
  • Marek Koprowski and
  • Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

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  • 276 [106]. The new catalytic reaction which replaced a previously described four-step synthesis [107], involved a tandem aldol condensation/dehydration and cyclization of the intermediate 275 to 276 (Scheme 77). In 1999, Ikeda and Mori have presented a cyclotrimerization of enones (e.g
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Published 09 Mar 2017

Self-optimisation and model-based design of experiments for developing a C–H activation flow process

  • Alexander Echtermeyer,
  • Yehia Amar,
  • Jacek Zakrzewski and
  • Alexei Lapkin

Beilstein J. Org. Chem. 2017, 13, 150–163, doi:10.3762/bjoc.13.18

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  • absence of a physical process model. Results of the training set and of sequential optimisation are shown. Information regarding the experimental conditions is given in Supporting Information File 1, Table S7. Catalytic reaction scheme showing C–H activation of an aliphatic secondary amine 1 to form the
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Published 24 Jan 2017

Diels–Alder reactions in confined spaces: the influence of catalyst structure and the nature of active sites for the retro-Diels–Alder reaction

  • Ángel Cantín,
  • M. Victoria Gomez and
  • Antonio de la Hoz

Beilstein J. Org. Chem. 2016, 12, 2181–2188, doi:10.3762/bjoc.12.208

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  • . Practically no differences were found on reaction rate nor on product distribution when the reaction occurs on nonporous silica, with Beta zeolite or even in absence of any solid. Considering that Aerosil is an amorphous solid, these results indicate that the catalytic reaction with pure silica Beta zeolite
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Published 13 Oct 2016

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

  • Lucie Brulíková,
  • Aidan Harrison,
  • Marvin J. Miller and
  • Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

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  • reproducibility of the regio- and stereoselectivity for this catalytic reaction. Conclusion Nitroso hetero-Diels–Alder reactions have been used successfully for the synthesis of many biologically active molecules. The success of this methodology may be explained in part by the high selectivity of this reaction
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Published 01 Sep 2016

On the cause of low thermal stability of ethyl halodiazoacetates

  • Magnus Mortén,
  • Martin Hennum and
  • Tore Bonge-Hansen

Beilstein J. Org. Chem. 2016, 12, 1590–1597, doi:10.3762/bjoc.12.155

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  • reaction relative to the rate in the absence of the substrates, confirming that the rate limiting step is the release of N2 to generate the free carbene. In our initial report on the Rh(II)-catalyzed cyclopropanation high yields were obtained using toluene as solvent [11]. The thermal non-catalytic
  • reaction, however, gave a complex mixture in this solvent. We found dichloromethane to be a more suitable solvent for the thermal reaction and did a back to back comparison to the Rh2(esp)2-catalyzed reaction in CH2Cl2. The results are displayed in Table 2 and can be summarized as follows: The thermal
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Published 26 Jul 2016

Development of chiral metal amides as highly reactive catalysts for asymmetric [3 + 2] cycloadditions

  • Yasuhiro Yamashita,
  • Susumu Yoshimoto,
  • Mark J. Dutton and
  • Shū Kobayashi

Beilstein J. Org. Chem. 2016, 12, 1447–1452, doi:10.3762/bjoc.12.140

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  • . Compared with the chiral CuOTf/Et3N system, the CuHMDS system showed higher reactivity, and the desired reactions proceeded in high yields and high selectivities with catalyst loadings as low as 0.01 mol %. Keywords: [3 + 2] cycloaddition; asymmetric reaction; catalytic reaction; low catalyst loading
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Published 13 Jul 2016

Molecular weight control in organochromium olefin polymerization catalysis by hemilabile ligand–metal interactions

  • Stefan Mark,
  • Hubert Wadepohl and
  • Markus Enders

Beilstein J. Org. Chem. 2016, 12, 1372–1379, doi:10.3762/bjoc.12.131

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  • [1] and has been applied for the development of improved transition metal catalysts [2][3][4][5][6][7]. The donor–acceptor interaction of the hemilabile moiety with the metal center should be weak enough to allow the displacement by a substrate, which should itself be transformed during the catalytic
  • reaction. The bonding ability of internal or external stabilizing ligands in relation to the substrate plays a crucial role. In contrast to external donors, a special feature of a hemilabile donor is the fact that only one stabilizing ligand per metal center is available. Consequently, a large excess of
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Published 04 Jul 2016

Selective bromochlorination of a homoallylic alcohol for the total synthesis of (−)-anverene

  • Frederick J. Seidl and
  • Noah Z. Burns

Beilstein J. Org. Chem. 2016, 12, 1361–1365, doi:10.3762/bjoc.12.129

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  • . Unlike Table 1, entry 1, which was taken to completion, bromochlorinations quenched at low conversion exhibited high enantioselectivity for 6, but also constitutional isomer ratios (cr) as low as 2:1 for 6:7 (not shown). These observations are consistent with a highly selective catalytic reaction
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Published 01 Jul 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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  • AgBF4 was used in place of AgOAc under optimized conditions for C–H arylation with aryl iodides, HBF4 (or any other added acid) was unnecessary for the catalytic reaction to occur. Here, since AgBF4 apparently reacts with I–Pd+BF4− to produce catalytically active Pd2+(BF4)2− (Scheme 22), and there are
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Published 20 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

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  • adducts after catalytic reaction and hydrolysis. 1H-Imidazol-4(5H)-ones 1 and thiazol-4(5H)-ones 2. Proposed model for the Michael addition of 1H-imidazol4-(5H)-ones and selected 1H NMR data which support it [55]. Ureidopeptide-like Brønsted bases: catalyst design. a) Previous known design. b) Proposed
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Published 09 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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  • of 71%. The suggested mechanism for this catalytic reaction involves a bifunctional activation. Utilizing the primary amino group, the authors proposed that the catalyst condenses to form an imine, which is in equilibrium with the corresponding enamine of isobutyraldehyde, while the two hydrogens of
  • the thiourea group interact with one or two carbonyl groups of phenylbutenoate 2 (Scheme 5). Another catalytic reaction catalyzed by a primary amine-thiourea that leads to multiple chiral centers is the asymmetric desymmetrization of 4,4-disubstituted cyclohexadienones 5, using the Michael addition of
  • ethyl malonate, producing the active nucleophile, while the thiourea group activates the electrophile (Scheme 6). The above catalytic reaction provided products with yields up to 99%, dr up to 93:7 and ee up to 93%. Carter and co-worker utilized a similar primary amine-thiourea, organocatalyst 11, in an
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Published 10 Mar 2016

Versatile deprotonated NHC: C,N-bridged dinuclear iridium and rhodium complexes

  • Albert Poater

Beilstein J. Org. Chem. 2016, 12, 117–124, doi:10.3762/bjoc.12.13

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  • effective for any catalytic reaction, but some successful applications were achieved in the field of Ru-catalyzed metathesis of olefins [9][10][11][12], Ir-catalyzed hydrogenation [13][14], Pd-catalyzed C=C coupling reactions [15][16], Ir-catalyzed CO2 fixation [17][18], and/or functionalization of alkenes
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Published 22 Jan 2016

Comparison of the catalytic activity for the Suzuki–Miyaura reaction of (η5-Cp)Pd(IPr)Cl with (η3-cinnamyl)Pd(IPr)(Cl) and (η3-1-t-Bu-indenyl)Pd(IPr)(Cl)

  • Patrick R. Melvin,
  • Nilay Hazari,
  • Hannah M. C. Lant,
  • Ian L. Peczak and
  • Hemali P. Shah

Beilstein J. Org. Chem. 2015, 11, 2476–2486, doi:10.3762/bjoc.11.269

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  • described in Figure 2 and Figure 3. Peaks consistent with the formation of CpDim are observed during catalysis, and approximately 40% of the Pd is in the form of CpDim upon completion of the catalytic reaction. In contrast, for Cin under the same conditions, only a small amount of Pd was determined to be in
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Published 08 Dec 2015

Synthesis of quinoline-3-carboxylates by a Rh(II)-catalyzed cyclopropanation-ring expansion reaction of indoles with halodiazoacetates

  • Magnus Mortén,
  • Martin Hennum and
  • Tore Bonge-Hansen

Beilstein J. Org. Chem. 2015, 11, 1944–1949, doi:10.3762/bjoc.11.210

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  • (non-catalytic) reaction, 1H NMR analysis of the crude reaction mixtures showed greater conversion of indole and less byproducts for the catalyzed reaction compared to the thermal reaction. We optimized the catalytic reaction conditions and found that dropwise addition of an ice-cooled solution of Br
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Published 20 Oct 2015

Asymmetric 1,4-bis(ethynyl)bicyclo[2.2.2]octane rotators via monocarbinol functionalization. Ready access to polyrotors

  • Cyprien Lemouchi and
  • Patrick Batail

Beilstein J. Org. Chem. 2015, 11, 1881–1885, doi:10.3762/bjoc.11.202

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  • variety of functionalization sequences of BCO rotators by performing nucleophilic reactions on the terminal alkyne [16] as well as Sonogashira coupling reactions [17]. One way to synthesize 1 is via a catalytic reaction to achieve the deprotection of a single 2-methyl-3-butyn-2-ol and transform the
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Published 09 Oct 2015

Synthesis and structures of ruthenium–NHC complexes and their catalysis in hydrogen transfer reaction

  • Chao Chen,
  • Chunxin Lu,
  • Qing Zheng,
  • Shengliang Ni,
  • Min Zhang and
  • Wanzhi Chen

Beilstein J. Org. Chem. 2015, 11, 1786–1795, doi:10.3762/bjoc.11.194

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  • 2 and 3 are a bit better than 1 for this transformation. The trans-effect of carbene ligand may promote the substitution of trans-positioned acetonitrile ligand by other substrates in the catalytic reaction. Since complexes 2 and 3 are found to be the efficient catalysts for transfer hydrogenation
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Published 30 Sep 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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  • , the insertion of an N-acetylglucosaminyl moiety (GlcNAc-) into an oligosaccharide chain was identified as the crucial step catalyzed by N-acetylglucosaminyltransferases (GnTs) in the presence of a metal co-factor. In this catalytic reaction, UDP-GlcNAc [uridine 5′-(2-acetamido-2-deoxy-D-glucopyranosyl
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Published 04 Sep 2015

Azirinium ylides from α-diazoketones and 2H-azirines on the route to 2H-1,4-oxazines: three-membered ring opening vs 1,5-cyclization

  • Nikolai V. Rostovskii,
  • Mikhail S. Novikov,
  • Alexander F. Khlebnikov,
  • Galina L. Starova and
  • Margarita S. Avdontseva

Beilstein J. Org. Chem. 2015, 11, 302–312, doi:10.3762/bjoc.11.35

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  • at all. Our study of the chemical behavior of 2H-azirines under Rh(II)-catalyzed decomposition of diazoketones was started with searching for optimal conditions for the catalytic reaction of 2,3-diphenyl-2H-azirine (1a) with 1-diazo-1-phenylpropan-2-one (2a), leading to oxazine 4a. The most
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Published 02 Mar 2015

The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde

  • Volodymyr V. Tkachenko,
  • Elena A. Muravyova,
  • Sergey M. Desenko,
  • Oleg V. Shishkin,
  • Svetlana V. Shishkina,
  • Dmytro O. Sysoiev,
  • Thomas J. J. Müller and
  • Valentin A. Chebanov

Beilstein J. Org. Chem. 2014, 10, 3019–3030, doi:10.3762/bjoc.10.320

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  • , salicylaldehyde (2) and acetoacetamide 3a in the presence of 5 mol % ytterbium triflate as a catalyst in ethanol under stirring at room temperature for 48 h led to the formation of the aforementioned dihydroisoxazolopyridine 5a in 69% yield. To our surprise the analogous catalytic reaction in ethyl alcohol under
  • -component catalytic reaction with 5-amino-3-methylisoxazole (1) and salicylaldehyde (2) does not confirm this hypothesis since compound 6 was not observed in this case (Table 3, entries 23, 24). As one possible reason we assumed that the presence of an acidic phenol group – distinguishing the amide 3h from
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Published 17 Dec 2014

Phosphinocyclodextrins as confining units for catalytic metal centres. Applications to carbon–carbon bond forming reactions

  • Matthieu Jouffroy,
  • Rafael Gramage-Doria,
  • David Sémeril,
  • Dominique Armspach,
  • Dominique Matt,
  • Werner Oberhauser and
  • Loïc Toupet

Beilstein J. Org. Chem. 2014, 10, 2388–2405, doi:10.3762/bjoc.10.249

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  • the corresponding coupling product in relatively high yield (71%; Table 4, entry 5). As already observed in the hydroformylation experiments, HUGPHOS-1 generally gave slightly better results than the larger HUGPHOS-2, which points to a catalytic reaction taking place outside the cavity. It is
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Published 15 Oct 2014

Synthesis of chiral N-phosphoryl aziridines through enantioselective aziridination of alkenes with phosphoryl azide via Co(II)-based metalloradical catalysis

  • Jingran Tao,
  • Li-Mei Jin and
  • X. Peter Zhang

Beilstein J. Org. Chem. 2014, 10, 1282–1289, doi:10.3762/bjoc.10.129

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  • catalytic reaction, with no detectable aziridine product but remaining of the starting azides (Table 1, entries 1–3). It should be noted that azide 2c was previously shown to be a productive nitrene source for the catalytic aziridination reaction only at a high temperature of 80 °C [20]. Afterwards, we were
  • reduction in reaction temperature (from 40 °C to 35 °C) and time (from 48 h to 36 h) was shown to have no obvious effect on both product yield and enantioselectivity (Table 1, entry 13). However, the catalytic reaction became significantly slower as the temperature further decreased. Under the optimized
  • -subtituted styrene 1e (Table 2, entry 5), the catalytic reaction of the sterically demanding o-Br-substituted olefin 1k gave the desired aziridine in almost quantitative yield as well as high enantioselectivity (Table 2, entry 11). It is worthy to mention that the aryl halide units of these chiral aziridines
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Published 04 Jun 2014

Cu-catalyzed trifluoromethylation of aryl iodides with trifluoromethylzinc reagent prepared in situ from trifluoromethyl iodide

  • Yuzo Nakamura,
  • Motohiro Fujiu,
  • Tatsuya Murase,
  • Yoshimitsu Itoh,
  • Hiroki Serizawa,
  • Kohsuke Aikawa and
  • Koichi Mikami

Beilstein J. Org. Chem. 2013, 9, 2404–2409, doi:10.3762/bjoc.9.277

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  • trifluoromethyl iodide and Zn dust in DMPU. The catalytic reaction proceeded to provide moderate to high yields and a high selectivity of the trifluoromethylated product under mild reaction conditions. The advantage of this catalytic reaction is that additives such as metal fluoride (MF), which are indispensable
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Published 08 Nov 2013

Computational study of the rate constants and free energies of intramolecular radical addition to substituted anilines

  • Andreas Gansäuer,
  • Meriam Seddiqzai,
  • Tobias Dahmen,
  • Rebecca Sure and
  • Stefan Grimme

Beilstein J. Org. Chem. 2013, 9, 1620–1629, doi:10.3762/bjoc.9.185

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  • -based transformations are amongst the most attractive methods for the use in catalytic cycles due to the ease of radical generation, high functional group tolerance, and selectivity in C–C bond formation [3][4][5]. Recently, we have reported a novel catalytic reaction, a radical arylation of epoxides [6
  • for the addition of 1 readily explains the excellent synthetic results with epoxides derived from aryl substituted anilines in the radical arylation of epoxides. The reaction of 3 is too slow to be useful in typical radical chain reactions. However, reactions under our catalytic reaction conditions [6
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Published 08 Aug 2013

Palladium(II)-catalyzed Heck reaction of aryl halides and arylboronic acids with olefins under mild conditions

  • Tanveer Mahamadali Shaikh and
  • Fung-E Hong

Beilstein J. Org. Chem. 2013, 9, 1578–1588, doi:10.3762/bjoc.9.180

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  • , entry 4). Therefore, it is believed that NBS plays an important role in this catalytic reaction. Furthermore, we focused our attention to other solvents such as MeOH, CH2Cl2, CH3CN, Me2O, t-Bu2O, THF, DMSO and 1,4-dioxane, which resulted in low yields of arylated product. Subsequently, the reaction was
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Published 05 Aug 2013
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