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Search for "Lewis-acid catalysis" in Full Text gives 38 result(s) in Beilstein Journal of Organic Chemistry.

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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  • -catalyzed process described in Scheme 31 takes advantage of the usual formation of 43 which undergoes a [3 + 3]-cycloaddition reaction with cyclopropanes 59 under nickel perchlorate catalysis. Cycloaddition reactions of activated cyclopropanes with nitrones under Lewis acid catalysis have been previously
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Published 26 Feb 2014

Studies on the interaction of isocyanides with imines: reaction scope and mechanistic variations

  • Ouldouz Ghashghaei,
  • Consiglia Annamaria Manna,
  • Esther Vicente-García,
  • Marc Revés and
  • Rodolfo Lavilla

Beilstein J. Org. Chem. 2014, 10, 12–17, doi:10.3762/bjoc.10.3

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  • Barcelona, Spain 10.3762/bjoc.10.3 Abstract The interaction of imines with isocyanides has been studied. The main product results from a sequential process involving the attack of two units of isocyanide, under Lewis acid catalysis, upon the carbon–nitrogen double bond of the imine to form the 4-membered
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Letter
Published 06 Jan 2014

Gallium-containing polymer brush film as efficient supported Lewis acid catalyst in a glass microreactor

  • Rajesh Munirathinam,
  • Roberto Ricciardi,
  • Richard J. M. Egberink,
  • Jurriaan Huskens,
  • Michael Holtkamp,
  • Herbert Wormeester,
  • Uwe Karst and
  • Willem Verboom

Beilstein J. Org. Chem. 2013, 9, 1698–1704, doi:10.3762/bjoc.9.194

Graphical Abstract
  • model substrate, and for the formation of oxazoles by ring closure of ortho-hydroxy oximes. The catalytic activity of the microreactor could be maintained by periodic reactivation by treatment with GaCl3. Keywords: dehydration of oximes; flow chemistry; gallium; microreactors; Lewis acid catalysis
  • easy fabrication of the catalytic device by filling the channels with functional catalytic particles, however, heat transfer limitations and pressure drop developing along the microchannel are serious drawbacks [7]. The literature contains numerous examples of Lewis acid catalysis [8][9][10][11
  • ]. However, only a limited number of papers are known dealing with heterogeneous Lewis acid catalysis, where a Lewis acid is tethered onto a solid surface like silica or gold [12][13]. Furthermore, to the best of our knowledge, there are no examples of the immobilization of a Lewis acid to a microreactor
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Published 16 Aug 2013

Diastereoselective synthesis of nitroso acetals from (S,E)-γ-aminated nitroalkenes via multicomponent [4 + 2]/[3 + 2] cycloadditions promoted by LiCl or LiClO4

  • Leandro Lara de Carvalho,
  • Robert Alan Burrow and
  • Vera Lúcia Patrocinio Pereira

Beilstein J. Org. Chem. 2013, 9, 838–845, doi:10.3762/bjoc.9.96

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  • the Lewis acid catalysis by cation–substrate interaction have been utilized to explain this enhancement of the reaction rate [12][13][14]. In the case of nitroalkene cycloadditions, performed in the presence of a Lewis acid, it is well documented that the rate acceleration effect caused by the Lewis
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Published 30 Apr 2013

Organocatalysis

  • Benjamin List

Beilstein J. Org. Chem. 2012, 8, 1358–1359, doi:10.3762/bjoc.8.156

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  • -molecular-weight organic compounds, in which a metal is not part of the active principle. Organocatalysts donate or remove electrons or protons as their activation mode, hence defining four distinct subareas: Lewis base and Lewis acid catalysis on the one hand, and Brønsted base and Brønsted acid catalysis
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Editorial
Published 23 Aug 2012

Two-directional synthesis as a tool for diversity-oriented synthesis: Synthesis of alkaloid scaffolds

  • Kieron M. G. O’Connell,
  • Monica Díaz-Gavilán,
  • Warren R. J. D. Galloway and
  • David R. Spring

Beilstein J. Org. Chem. 2012, 8, 850–860, doi:10.3762/bjoc.8.95

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  • particular reference to the synthesis of polycyclic alkaloid scaffolds. Keywords: alkaloids; cascade reactions; chemical diversity; diversity-oriented synthesis; Lewis acid catalysis; two-directional synthesis; Introduction Diversity-oriented synthesis (DOS) aims to prepare structurally diverse compound
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Published 06 Jun 2012

An intramolecular inverse electron demand Diels–Alder approach to annulated α-carbolines

  • Zhiyuan Ma,
  • Feng Ni,
  • Grace H. C. Woo,
  • Sie-Mun Lo,
  • Philip M. Roveto,
  • Scott E. Schaus and
  • John K. Snyder

Beilstein J. Org. Chem. 2012, 8, 829–840, doi:10.3762/bjoc.8.93

Graphical Abstract
  • cycloaddition of 17a. Preparation of N-protected isatin-derived 1,2,4-triazines 8.a Lewis acid catalysis of amidation of triazine 8a.a IEDDA reaction conditions of 13a to give cycloadduct 14a.a Amidation-IEDDA sequence to α-carbolines 14 from triazine 8a.a Library synthesis matrix.a Supporting Information
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Published 06 Jun 2012

A practical route to tertiary diarylmethylamides or -carbamates from imines, organozinc reagents and acyl chlorides or chloroformates

  • Erwan Le Gall,
  • Antoine Pignon and
  • Thierry Martens

Beilstein J. Org. Chem. 2011, 7, 997–1002, doi:10.3762/bjoc.7.112

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  • -substituted aldimines, formed in situ upon reaction of primary amines with aromatic aldehydes, cannot be undertaken under our established conditions. Thus, we intended to activate the C=N double bond by rendering the carbon more electrophilic and we initially envisaged the use of Lewis acid catalysis. Indeed
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Letter
Published 20 Jul 2011

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

  • Marcus Baumann,
  • Ian R. Baxendale,
  • Steven V. Ley and
  • Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

Graphical Abstract
  • an α-bromo ketone and an excess of aniline to give a 2-arylindole derivative 110 [31] (Scheme 24). For a long time this procedure has received little attention due to the requirement for rather extreme reaction conditions. However, the use of microwave radiation in combination with Lewis acid
  • catalysis allows the reaction to be conducted much more efficiently [32]. This gives mid range yields (50–70%) of the 2-arylindoles over the two step sequence and tolerates a selection of functional groups on the aniline ring. Fluvastatin (2, Lescol), a HMG-CoA reductase inhibitor was initially prepared by
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Published 18 Apr 2011

Kinetics and mechanism of vanadium catalysed asymmetric cyanohydrin synthesis in propylene carbonate

  • Michael North and
  • Marta Omedes-Pujol

Beilstein J. Org. Chem. 2010, 6, 1043–1055, doi:10.3762/bjoc.6.119

Graphical Abstract
  • Lewis base catalysis is dominant; and b) when Lewis acid catalysis is dominant. Hammett correlations with catalyst 2 at 0 °C. Data in red are obtained in dichloromethane [52], whilst data in blue are obtained in propylene carbonate. Synthesis and transformation of nonracemic silyl-protected cyanohydrins
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Published 03 Nov 2010

A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis

  • Magnus Rueping and
  • Boris J. Nachtsheim

Beilstein J. Org. Chem. 2010, 6, No. 6, doi:10.3762/bjoc.6.6

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  • –Crafts alkylation; green chemistry; hydroalkylation; hydroarylation; Lewis-acid catalysis; propargyl alcohols; Introduction In 1887 Charles Friedel and James Mason Crafts isolated amylbenzene after the treatment of amyl chloride with AlCl3 in benzene (Scheme 1) [1]. This was not only one of the first
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Published 20 Jan 2010

Recent progress on the total synthesis of acetogenins from Annonaceae

  • Nianguang Li,
  • Zhihao Shi,
  • Yuping Tang,
  • Jianwei Chen and
  • Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

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Published 05 Dec 2008

Allylsilanes in the synthesis of three to seven membered rings: the silylcuprate strategy

  • Asunción Barbero,
  • Francisco J. Pulido and
  • M. Carmen Sañudo

Beilstein J. Org. Chem. 2007, 3, No. 16, doi:10.1186/1860-5397-3-16

Graphical Abstract
  • under Lewis acid catalysis. [10] Thus, silicon assisted cyclization of oxoallylsilanes 3–8 in the presence of TiCl4 or EtAlCl2 results in the formation of 3-methylene-1-cyclopentanols 11–14 with a high degree of stereocontrol (Scheme 3). [7] The cis stereochemistry observed in 11 might indicate a
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Published 22 May 2007
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