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Search for "alkenylation" in Full Text gives 62 result(s) in Beilstein Journal of Organic Chemistry.

Consecutive cross-coupling reactions of 2,2-difluoro-1-iodoethenyl tosylate with boronic acids: efficient synthesis of 1,1-diaryl-2,2-difluoroethenes

  • Ju Hee Kim,
  • Su Jeong Choi and
  • In Howa Jeong

Beilstein J. Org. Chem. 2013, 9, 2470–2475, doi:10.3762/bjoc.9.286

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  • of 2 with arylboronic acids prompted us to examine similar coupling reactions with alkenylboronic acids. The same reaction conditions of the mono-coupling reaction of 2 with arylboronic acid was applied to the alkenylation of 2. Therefore, the cross-coupling reaction of 2 with trans-2
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Published 14 Nov 2013

AgOTf-catalyzed one-pot reactions of 2-alkynylbenzaldoximes with α,β-unsaturated carbonyl compounds

  • Qiuping Ding,
  • Dan Wang,
  • Puying Luo,
  • Meiling Liu,
  • Shouzhi Pu and
  • Liyun Zhou

Beilstein J. Org. Chem. 2013, 9, 1949–1956, doi:10.3762/bjoc.9.231

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  • ). This observation indicated that the Palladium-catalyzed alkenylation reaction mechanism might be similar to that described by Cui and Wu [46]. Conclusion In summary, we have demonstrated that one-pot reactions of 2-alkynylbenzaldoximes with α,β-unsaturated carbonyl compounds catalyzed by AgOTf occur
  • File 1. Proposed route for the AgOTf-catalyzed one-pot reaction of 2-alkynylbenzaldoxime with an α,β-unsaturated carbonyl compound. Synthesis of 1-alkylated isoquinoline 3a by a AgOTf-catalyzed one-pot reaction in different solvents. Pd-catalyzed one-pot alkenylation reaction of 2-alkynylbenzaldoxime
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Published 27 Sep 2013

Iron-catalyzed decarboxylative alkenylation of cycloalkanes with arylvinyl carboxylic acids via a radical process

  • Jincan Zhao,
  • Hong Fang,
  • Jianlin Han and
  • Yi Pan

Beilstein J. Org. Chem. 2013, 9, 1718–1723, doi:10.3762/bjoc.9.197

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  • excellent stereoselectivity, and only trans-isomers are obtained. Keywords: alkenylation; cycloalkanes; decarboxylative; Fe(acac)3; free radical; sp3 C–H bonds; Introduction Direct C–H functionalization has become one of the most useful and attractive tools in organic chemistry because it can construct
  • alkenylation of cycloalkanes with high selectivity and stereospecificity remains a great challenge and attracted a lot of attention in the past years. In 1996, the Fuchs group described the alkenylation of cyclohexane by a radical reaction with vinyl triflone [58]. In 2003, the Yao group reported that styryl
  • ][68]. Our group was surprised to find that low-cost Fe(acac)3 could catalyze the direct alkenylation of cyclohexane sp3 C–H bonds by decarboxylative couplings with high efficiency. Results and Discussion We initiated our investigation by reacting cinnamic acid (1a, 0.3 mmol) with cyclohexane (2a, 2 mL
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Published 21 Aug 2013

Direct alkenylation of indolin-2-ones by 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles: a novel approach

  • Sandeep Kumar,
  • Ramendra Pratap,
  • Abhinav Kumar,
  • Brijesh Kumar,
  • Vishnu K. Tandon and
  • Vishnu Ji Ram

Beilstein J. Org. Chem. 2013, 9, 809–817, doi:10.3762/bjoc.9.92

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  • , Lucknow-226001, India 10.3762/bjoc.9.92 Abstract A direct one-pot base-induced alkenylation of indolin-2-ones has been developed by using 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles. Different bases such as MeONa, NaH and t-BuONa have been used to optimize the reaction conditions to obtain the
  • desired product. NaH in THF was found to be the most suitable for the alkenylation of indolin-2-ones. Reaction in the presence of other bases led to the formation of 1-aryl-3-methoxy/methylthio-5H-dibenzo[d,f][1,3]diazepin-6(7H)-ones. Quantum chemical calculations have been performed to explain the nature
  • of the weak noncovalent interactions operating in the supramolecular architectures of alkenylated indoline-2-ones and to explain the relative stability of one of the tautomers with respect to the others. Keywords: alkenylation; dibenzo[d,f][1,3]diazepin-6(7H)-one; indolin-2-one; ketene dithioacetal
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Published 25 Apr 2013

Titanium-mediated reductive cross-coupling reactions of imines with terminal alkynes: An efficient route for the synthesis of stereodefined allylic amines

  • Kebin Mao,
  • Guoqin Fan,
  • Yuanhong Liu,
  • Shi Li,
  • Xu You and
  • Dan Liu

Beilstein J. Org. Chem. 2013, 9, 621–627, doi:10.3762/bjoc.9.69

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  • ], iodocyclocarbamates [19] and isoxazolines [20]. Although it has been reported that allylic amines can be synthesized by methods such as amination of allylic alcohols [21][22][23][24], direct allylic amination of simple alkenes [25][26][27], Morita–Baylis–Hillman reaction [28], alkenylation of imines [29][30][31][32
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Published 27 Mar 2013

Iron-containing mesoporous aluminosilicate catalyzed direct alkenylation of phenols: Facile synthesis of 1,1-diarylalkenes

  • Satyajit Haldar and
  • Subratanath Koner

Beilstein J. Org. Chem. 2013, 9, 49–55, doi:10.3762/bjoc.9.6

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  • reagents to afford 1,1-disubstituted olefins [27]. Alternatively, Friedel–Crafts-type alkenylation could be a better choice to prepare such regiospecific vinyl aromatic compounds. Yamaguchi et al. reported a direct ortho alkenylation of phenols with 1-alkynes using SnCl4 and Bu3N in acetonitrile under
  • reflux [28]. Further developments include the metal trifluoromethanesulfonate-catalyzed Friedel–Crafts alkenylation of arenes using alkynes by Tsuchimoto et al. [29] and the addition of simple arenes to arylacetylenes to afford exclusive 1,1-diarylethylenes through a C–C coupling reaction catalyzed by a
  • conditions”. On further exploration of the use of iron-based mesoporous aluminosilicate catalyst in the direct alkenylation of arenes, we have succeeded in vinylation of various phenols with different phenylacetylenes. In this paper we report a convenient method for the alkenylation of phenols with aryl
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Published 09 Jan 2013

Palladium-catalyzed dual C–H or N–H functionalization of unfunctionalized indole derivatives with alkenes and arenes

  • Gianluigi Broggini,
  • Egle M. Beccalli,
  • Andrea Fasana and
  • Silvia Gazzola

Beilstein J. Org. Chem. 2012, 8, 1730–1746, doi:10.3762/bjoc.8.198

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  • . Keywords: alkenylation; arylation; C–H functionalization; indoles; N–H functionalization; Pd catalysis; Introduction The development of mild and selective reactions for the direct conversion of carbon–hydrogen bonds into carbon–carbon and carbon–heteroatom bonds is a challenging goal in organic chemistry
  • domino processes. Review Intermolecular reactions involving alkenes Alkenylation reactions of indoles run through a key C–H activation step involving an electrophilic palladation and an electron-deficient Pd(II) catalyst. The mechanism of these reactions involves the generation of a σ-alkyl complex I
  • rearrangement that is operative during the alkylation of indoles [46]. In 1969, Fujiwara and Moritani reported the alkenylation of arenes catalyzed by Pd(OAc)2, using Cu(OAc)2 or AgOAc as oxidants [47]. This strategy provides a convenient method for the synthesis of olefins linked to heteroarenes, including
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Published 11 Oct 2012

C2-Alkylation of N-pyrimidylindole with vinylsilane via cobalt-catalyzed C–H bond activation

  • Zhenhua Ding and
  • Naohiko Yoshikai

Beilstein J. Org. Chem. 2012, 8, 1536–1542, doi:10.3762/bjoc.8.174

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  • reaction conditions and unique regioselectivities [23][24][25][26][27][28][29][30][31][32]. As a part of this research program, we have recently reported a C2-alkenylation reaction of N-pyrimidylindoles with internal alkynes catalyzed by a cobalt–pyridylphosphine complex (Scheme 1a) [33], in which the
  • pyphos, which was the optimum ligand for the alkenylation reaction [33], was poorly effective (Table 1, entry 6). Additional screening of N-heterocyclic carbene (NHC) and phosphine ligands did not lead to an improvement of the catalytic efficiency (Table 1, entries 7–9). The reaction turned out to be
  • Cl) and electron-donating (OMe) substituents and steric hindrance at the C3 and C7 positions. Unlike the cobalt-catalyzed C2-alkenylation reaction (Scheme 1a) [33], the reaction did not tolerate a cyano group on the indole substrate. In addition, N-pyrimidyl benzimidazole did not participate in the
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Published 14 Sep 2012

Alkoxide-induced ring opening of bicyclic 2-vinylcyclobutanones: A convenient synthesis of 2-vinyl-substituted 3-cycloalkene-1-carboxylic acid esters

  • Xiufang Ji,
  • Zhiming Li,
  • Quanrui Wang and
  • Andreas Goeke

Beilstein J. Org. Chem. 2012, 8, 650–657, doi:10.3762/bjoc.8.72

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  • bicyclic cyclohexenols [16], which were also subsequently described by Cohen who elaborated the method into a synthesis of (−)-β-selinene [17]. The core structures of ophiobolins A and other natural products can be synthesized by an alkenylation/oxy-Cope/methylation sequence of vinylcyclobutones in one pot
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Published 26 Apr 2012

Synthesis of fluoranthenes by hydroarylation of alkynes catalyzed by gold(I) or gallium trichloride

  • Sergio Pascual,
  • Christophe Bour,
  • Paula de Mendoza and
  • Antonio M. Echavarren

Beilstein J. Org. Chem. 2011, 7, 1520–1525, doi:10.3762/bjoc.7.178

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  • the synthesis of complex molecules under mild conditions [1][2][3][4][5][6][7][8]. Alkynes can react in gold-catalyzed Friedel–Crafts-type reactions with arenes to give products resulting from the intermolecular hydroarylation of the alkynes (or alkenylation of the arenes) [9][10][11][12][13][14][15
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Published 14 Nov 2011

Amines as key building blocks in Pd-assisted multicomponent processes

  • Didier Bouyssi,
  • Nuno Monteiro and
  • Geneviève Balme

Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163

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  • basic media. A subsequent Pd-mediated intermolecular alkylation with the dihalogeno substrate followed by an intramolecular N-arylation furnished 2-substituted indoles 68. In this cascade reaction, the palladium catalyst intervenes in three different coupling reactions: Intermolecular N-alkenylation, C
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Published 10 Oct 2011

The enantiospecific synthesis of (+)-monomorine I using a 5-endo- trig cyclisation strategy

  • Malcolm B. Berry,
  • Donald Craig,
  • Philip S. Jones and
  • Gareth J. Rowlands

Beilstein J. Org. Chem. 2007, 3, No. 39, doi:10.1186/1860-5397-3-39

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  • anion of 1 forms the first C-C bond and furnishes 3. Modification of the work of Julia [7][8][9] then utilises the sulfone to facilitate stereocontrolled alkenylation to give the cyclisation substrate 4. Finally, 5-endo-trig cyclisation yields the desired heterocycles 5. Overall, the sulfone moiety
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Published 08 Nov 2007
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