Search results

Search for "N-heterocyclic carbene" in Full Text gives 139 result(s) in Beilstein Journal of Organic Chemistry.

Synthesis of chiral mono(N-heterocyclic carbene) palladium and gold complexes with a 1,1'-biphenyl scaffold and their applications in catalysis

  • Lian-jun Liu,
  • Feijun Wang,
  • Wenfeng Wang,
  • Mei-xin Zhao and
  • Min Shi

Beilstein J. Org. Chem. 2011, 7, 555–564, doi:10.3762/bjoc.7.64

Graphical Abstract
  • showed good catalytic activities in the asymmetric intramolecular hydroamination reaction to give the corresponding product in moderate ee. Keywords: chiral mono(N-heterocyclic carbene) complex; Heck–Mizoroki reaction; hydroamination; Suzuki–Miyaura reaction; Introduction N-heterocyclic carbene (NHC
  • –Au(I) complex (S)-6a with thermal ellipsoids at the 30% probability level. Selected bond distances (Å) and angles (deg): Au1–C1 = 2.036(14), Au1–I1 = 2.5093(13), C1–Au1–I1 = 176.5(3), N1–C1–Au1 = 125.7(9), N2–C1–Au = 126.1(9). Synthesis of N-heterocyclic carbene precursor. Synthesis of mono(NHC)–Pd
PDF
Album
Supp Info
Full Research Paper
Published 04 May 2011

Ene–yne cross-metathesis with ruthenium carbene catalysts

  • Cédric Fischmeister and
  • Christian Bruneau

Beilstein J. Org. Chem. 2011, 7, 156–166, doi:10.3762/bjoc.7.22

Graphical Abstract
  • intermolecular ene–yne metathesis versions [33][34][35][36][37][38]. For EYCM the two pathways involve either an alkyne interaction with a methylidene metal species (Scheme 3) or an alkylidene metal intermediate (Scheme 4). In both cases, the ancillary ligands tricyclohexylphosphine or N-heterocyclic carbene
PDF
Album
Review
Published 04 Feb 2011

Olefin metathesis in nano-sized systems

  • Didier Astruc,
  • Abdou K. Diallo,
  • Sylvain Gatard,
  • Liyuan Liang,
  • Cátia Ornelas,
  • Victor Martinez,
  • Denise Méry and
  • Jaime Ruiz

Beilstein J. Org. Chem. 2011, 7, 94–103, doi:10.3762/bjoc.7.13

Graphical Abstract
  • an intermediate tetracyclic iron arene complex. Furthermore and interestingly, when the metathesis reaction was carried out in refluxing dichloroethane with the addition of the second-generation Grubbs catalyst [RuCl2(=CHPh)(bis-N-mesityl-NHC)], 7, (Scheme 3, NHC = N-heterocyclic carbene), the di
PDF
Album
Review
Published 19 Jan 2011

Palladium- and copper-mediated N-aryl bond formation reactions for the synthesis of biological active compounds

  • Carolin Fischer and
  • Burkhard Koenig

Beilstein J. Org. Chem. 2011, 7, 59–74, doi:10.3762/bjoc.7.10

Graphical Abstract
  • ]. Industrial scale-up of these methods has already been applied on the 100 kg scale for arylpiperazines and different diarylamines [21]. In addition, Nolan et al. and Organ et al. have reported Pd-N-heterocyclic carbene (NHC)-catalysed Buchwald–Hartwig amination protocols that provide access to a range of
PDF
Album
Review
Published 14 Jan 2011

The intriguing modeling of cis–trans selectivity in ruthenium-catalyzed olefin metathesis

  • Naeimeh Bahri-Laleh,
  • Raffaele Credendino and
  • Luigi Cavallo

Beilstein J. Org. Chem. 2011, 7, 40–45, doi:10.3762/bjoc.7.7

Graphical Abstract
  • SIMes N-heterocyclic carbene ligand, see Scheme 2. Although it is well known that the steric hindrance of the olefin substituent has a remarkable role on both reactivity and products distribution, propene can still be considered as a prototype of terminal olefins, and can provide insights into the
PDF
Album
Letter
Published 11 Jan 2011

The cross-metathesis of methyl oleate with cis-2-butene-1,4-diyl diacetate and the influence of protecting groups

  • Arno Behr and
  • Jessica Pérez Gomes

Beilstein J. Org. Chem. 2011, 7, 1–8, doi:10.3762/bjoc.7.1

Graphical Abstract
  • ) starting from renewable resources and quite inexpensive base chemicals. Results: This cross-metathesis reaction was carried out with several phosphine and N-heterocyclic carbene ruthenium catalysts. The reaction conditions were optimised for high conversions in combination with high cross-metathesis
  • conversions in combination with high cross-metathesis selectivities. Additionally, several phosphine and N-heterocyclic carbene ruthenium catalysts were studied. The optimised reaction conditions were subsequently investigated in the cross-metathesis reaction of oleic acid (7) with the unprotected cis-2
  • bearing N-heterocyclic carbene ligands (Table 1, entries 2 and 4–8) [29]. Up to 48% of methyl oleate (1) was converted and the yields of the cross-metathesis products 3 and 4 of ca. 28% were achievable with ruthenium catalysts [Ru]-2 and [Ru]-4 (Table 1, entries 2 and 4). Here, the self-metathesis
PDF
Album
Full Research Paper
Published 03 Jan 2011

New library of aminosulfonyl-tagged Hoveyda–Grubbs type complexes: Synthesis, kinetic studies and activity in olefin metathesis transformations

  • Etienne Borré,
  • Frederic Caijo,
  • Christophe Crévisy and
  • Marc Mauduit

Beilstein J. Org. Chem. 2010, 6, 1159–1166, doi:10.3762/bjoc.6.132

Graphical Abstract
  • been facilitated [2][3][4]. However, many research groups have focused their research on the development of more efficient precatalysts (Figure 1). In 1999, Grubbs (1a) [5] and Nolan (1b) [6] reported ruthenium species bearing one N-heterocyclic carbene (NHC) moiety. Despite the stability enhancement
PDF
Album
Supp Info
Full Research Paper
Published 06 Dec 2010

Backbone tuning in indenylidene–ruthenium complexes bearing an unsaturated N-heterocyclic carbene

  • César A. Urbina-Blanco,
  • Xavier Bantreil,
  • Hervé Clavier,
  • Alexandra M. Z. Slawin and
  • Steven P. Nolan

Beilstein J. Org. Chem. 2010, 6, 1120–1126, doi:10.3762/bjoc.6.128

Graphical Abstract
  • parameters. Keywords: N-heterocyclic carbene; olefin metathesis; percent buried volume; ruthenium–indenylidene; Tolman electronic parameter; Introduction The use of N-heterocyclic carbenes (NHC) as spectator ligands in ruthenium-mediated olefin metathesis represents one of the most important breakthroughs
PDF
Album
Supp Info
Video
Full Research Paper
Published 23 Nov 2010

Light-induced olefin metathesis

  • Yuval Vidavsky and
  • N. Gabriel Lemcoff

Beilstein J. Org. Chem. 2010, 6, 1106–1119, doi:10.3762/bjoc.6.127

Graphical Abstract
  • respective yields and the required reaction times. In line with the development of ruthenium benzylidene initiators [66][67], the phosphane ligand was replaced by an N-heterocyclic carbene (NHCs) in the photoactivated precatalysts. Accordingly, Noels et al. [68][69] synthesised a range of NHC substituted
PDF
Album
Review
Published 23 Nov 2010

Halide exchanged Hoveyda-type complexes in olefin metathesis

  • Julia Wappel,
  • César A. Urbina-Blanco,
  • Mudassar Abbas,
  • Jörg H. Albering,
  • Robert Saf,
  • Steven P. Nolan and
  • Christian Slugovc

Beilstein J. Org. Chem. 2010, 6, 1091–1098, doi:10.3762/bjoc.6.125

Graphical Abstract
  • 16.10 ppm. All other features of the 1H NMR spectrum of 2 are similar to those of 1 indicating slightly hindered rotation of the N-heterocyclic carbene ligand and a trans-disposition of the two halide ligands. In contrast, the rotation of the NHC ligand around the Ru–NHC bond in 3 is hindered as shown
PDF
Album
Supp Info
Full Research Paper
Published 23 Nov 2010
Graphical Abstract
  • . Various aryltriazenes were investigated as electrophilic substrates at room temperature to give biaryls in good to excellent yields and showed good chemoselectivity over aryl halides in the reactions. Keywords: 1-aryltriazenes; N-heterocyclic carbene–palladium complex; polymer-supported catalyst
  • general study on the Suzuki–Miyaura reactions of 1-aryltriazenes under heterogeneous catalysis described to date. Previously, we reported an active and recyclable polystyrene-supported Pd–NHC (N-heterocyclic carbene) catalyst 1 (Scheme 1) for the Suzuki–Miyaura cross-coupling reactions of aryl bromides
PDF
Album
Full Research Paper
Published 28 Jun 2010

The C–F bond as a conformational tool in organic and biological chemistry

  • Luke Hunter

Beilstein J. Org. Chem. 2010, 6, No. 38, doi:10.3762/bjoc.6.38

Graphical Abstract
  • , Figure 10), with the key transannular aldol reaction (44→45) proceeding in high yield and with impressive enantioselectivity [35]. Fluorine-substituted organocatalysts are also useful in the asymmetric Stetter reaction (Figure 11) [36]. N-Heterocyclic carbene 49 was identified as a promising first
PDF
Album
Review
Published 20 Apr 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

Graphical Abstract
  • *-catalyst 33 (Scheme 14). This N-heterocyclic carbene Ir-complex is capable of catalyzing FC alkylations not only with benzyl alcohols and styrenes but also utilizing aldehydes and acetophenones 32, which are reduced prior to the FC-type alkylation in the same reaction vessel (Scheme 14). Here isopropanol
PDF
Album
Review
Published 20 Jan 2010

Expedient syntheses of the N-heterocyclic carbene precursor imidazolium salts IPr·HCl, IMes·HCl and IXy·HCl

  • Lukas Hintermann

Beilstein J. Org. Chem. 2007, 3, No. 22, doi:10.1186/1860-5397-3-22

Graphical Abstract
  • -dimethylphenyl), precursors to widely used N-heterocyclic carbene (NHC) ligands and catalysts, were prepared in high yields (81%, 69% and 89%, respectively) by the reaction of 1,4-diaryl-1, 4-diazabutadienes, paraformaldehyde and chlorotrimethylsilane in dilute ethyl acetate solution. A reaction mechanism
PDF
Album
Supp Info
Full Research Paper
Published 28 Aug 2007
Other Beilstein-Institut Open Science Activities