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Search for "[3 2] cycloaddition" in Full Text gives 126 result(s) in Beilstein Journal of Organic Chemistry.

AgNTf2-catalyzed formal [3 + 2] cycloaddition of ynamides with unprotected isoxazol-5-amines: efficient access to functionalized 5-amino-1H-pyrrole-3-carboxamide derivatives

  • Ziping Cao,
  • Jiekun Zhu,
  • Li Liu,
  • Yuanling Pang,
  • Laijin Tian,
  • Xuejun Sun and
  • Xin Meng

Beilstein J. Org. Chem. 2019, 15, 2623–2630, doi:10.3762/bjoc.15.255

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  • Analysis, Qufu 273165, P. R. China 10.3762/bjoc.15.255 Abstract A formal [3 + 2] cycloaddition between ynamides and unprotected isoxazol-5-amines has been developed in the presence of catalytic AgNTf2 in an open flask. By the protocol, a variety of functionalized 5-amino-1H-pyrrole-3-carboxamide
  • use of an inexpensive catalyst, simple reaction conditions, simple work-up without column chromatographic purification for most of products and high yields. Keywords: [3 + 2] cycloaddition; isoxazole; pyrrole; silver catalysis; ynamide; Introduction Silver-catalyzed transformations of alkynes have
  • employment of isoxazole nucleophiles in gold-catalyzed formal [3 + 2] cycloaddition reaction of ynamides [31][32], and zinc-catalyzed the reaction of ynol ethers [33], giving the respective multi-substituted pyrrole derivatives efficiently (Scheme 2a) [34][35]. The reaction proceeds via an α-imino gold
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Published 04 Nov 2019

Alkylation of lithiated dimethyl tartrate acetonide with unactivated alkyl halides and application to an asymmetric synthesis of the 2,8-dioxabicyclo[3.2.1]octane core of squalestatins/zaragozic acids

  • Herman O. Sintim,
  • Hamad H. Al Mamari,
  • Hasanain A. A. Almohseni,
  • Younes Fegheh-Hassanpour and
  • David M. Hodgson

Beilstein J. Org. Chem. 2019, 15, 1194–1202, doi:10.3762/bjoc.15.116

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  • area have recently culminated in two communicated syntheses of 6,7-dideoxysqualestatin H5 (DDSQ (2), Figure 1) [12][13]. The centrepiece of both of these strategies is a rhodium(II)-catalysed tandem carbon ylide formation from a diazoketone 3 (Scheme 1) and stereoselective [3 + 2] cycloaddition with a
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Published 31 May 2019

Synthesis of aryl cyclopropyl sulfides through copper-promoted S-cyclopropylation of thiophenols using cyclopropylboronic acid

  • Emeline Benoit,
  • Ahmed Fnaiche and
  • Alexandre Gagnon

Beilstein J. Org. Chem. 2019, 15, 1162–1171, doi:10.3762/bjoc.15.113

Graphical Abstract
  • diastereoselective [3 + 2] cycloaddition reaction [14][15]. The ring expansion sequence 1 → 2 → 6 → 8 has been used as a key step in the synthesis of (±)-fragranol [16], (±)-grandisol [16], (±)-α-cuparenone [17] and (±)-herbertene [17]. Aryl cycloropyl sulfides 1 are most frequently prepared by cyclopropylation of
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Published 27 May 2019

Dirhodium(II)-catalyzed [3 + 2] cycloaddition of N-arylaminocyclopropane with alkyne derivatives

  • Wentong Liu,
  • Yi Kuang,
  • Zhifan Wang,
  • Jin Zhu and
  • Yuanhua Wang

Beilstein J. Org. Chem. 2019, 15, 542–550, doi:10.3762/bjoc.15.48

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  • cycloaddition chemistry based on compound 1. Zheng et al. [7] first reported on the [3 + 2] cycloaddition reaction of 1 with an alkene or alkyne mediated by visible light by the aid of the photocatalyst [Ru(bpz)3](PF6)2. Our group reported the metal catalyst itself, particularly the dinuclear rhodium complex
  • biomedical research [25][26][27][28][29]. Thus, based on this cycloaddition protocol, a convenient strategy can be established to synthesize trans-cyclic β-amino acids. The mechanism of the [3 + 2] cycloaddition reaction of 1a and 2a is similar to that previously reported [18] (Scheme 3). The distonic
  • -centered radical B, which continues to catalyzing the reaction. Conclusion In conclusion, we report on the [3 + 2] cycloaddition reaction catalyzed by dirhodium(II) based on arylcyclopropylamine, which broadens the scope of this method to the alkynyl group. This study demonstrated that this cycloaddition
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Published 25 Feb 2019

Synthesis of cis-hydrindan-2,4-diones bearing an all-carbon quaternary center by a Danheiser annulation

  • Gisela V. Saborit,
  • Carlos Cativiela,
  • Ana I. Jiménez,
  • Josep Bonjoch and
  • Ben Bradshaw

Beilstein J. Org. Chem. 2018, 14, 2597–2601, doi:10.3762/bjoc.14.237

Graphical Abstract
  • Lycopodium alkaloids carinatine A [11][14][15], 8-deoxyserratinine [10], fawcettidine [10], fawcettimine [7][10], lycojaponicumin C [10], lycopladine A [11][13][14][15], lycoposerramine R [13][14], and sieboldine [19][20] (Figure 2). Results and Discussion Despite the potential of [3 + 2] cycloaddition
  • have been used to build the hydrindane bicyclic system, but incorporating a different functionalization pattern in the cyclic compounds. Proposed here is a new methodological approach to functionalized 3a-substituted hydrindane synthesis based on a Danheiser annulation involving a [3 + 2] cycloaddition
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Published 09 Oct 2018

Catalyst-free synthesis of 4-acyl-NH-1,2,3-triazoles by water-mediated cycloaddition reactions of enaminones and tosyl azide

  • Lu Yang,
  • Yuwei Wu,
  • Yiming Yang,
  • Chengping Wen and
  • Jie-Ping Wan

Beilstein J. Org. Chem. 2018, 14, 2348–2353, doi:10.3762/bjoc.14.210

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  • numerous organic compounds [24][25][26][27][28]. The amazingly rapid and broad permeation of 1,2,3-triazoles to multidisciplinary areas can majorly be attributed to the occurrence of robust synthetic methods toward this heterocycle. The copper-catalyzed click [3 + 2] cycloaddition of azides and alkynes [29
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Published 07 Sep 2018

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

  • Michael K. Bogdos,
  • Emmanuel Pinard and
  • John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

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  • the [3 + 2]-cycloaddition of electron-poor alkynes and 2H-azirines [60]. The reaction is performed under blue LED irradiation and using acridinium salts as a photocatalyst (Scheme 15). With respect to 2H-azirine the scope of the reaction is demonstrated to be relatively broad, with aromatics
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Published 03 Aug 2018

Synthesis of new tricyclic 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepine derivatives by [3+ + 2]-cycloaddition/rearrangement reactions

  • Lin-bo Luan,
  • Zi-jie Song,
  • Zhi-ming Li and
  • Quan-rui Wang

Beilstein J. Org. Chem. 2018, 14, 1826–1833, doi:10.3762/bjoc.14.155

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  • ][1,4]diazepinium salts 10 and the related neutral, free bases 13 were synthesized from 4-acetoxy-1-acetyl-4-phenylazo-1,2,3,4-tetrahydroquinolines 8 and nitriles 9 in the presence of aluminium chloride by the [3+ + 2]-cycloaddition reaction of the in situ generated azocarbenium intermediates 14
  • ][26][27][28][29][30]. Over the past years, we have been engaged in the synthesis of novel 1,2,4-triazolo heterocycles annulated to benzoazepine or heteroazepine derivatives by a tandem [3+ + 2]-cycloaddition/rearrangement between 1-aza-2-azoniaallenium ions with nitriles [31][32][33][34]. In the [3
  • , we wish to describe the synthesis of unprecedented tricyclic heterocycles, i.e., 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepinium salts 10 and the related neutral free base derivatives 13 via the cationic [3+ + 2]-cycloaddition/rearrangement reactions using the bicyclic 4-acetoxy-4-azo
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Published 18 Jul 2018

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

  • Gwendal Grelier,
  • Benjamin Darses and
  • Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

Graphical Abstract
  • mechanism that first involves the formation of a 2’-iodobiphenyl-2-azide promoted by the copper complex. The latter then catalyzes an intermolecular [3 + 2] cycloaddition with the alkyne. Finally, the copper-triazole moiety inserts intramolecularly into the second Ar–I bond, allowing a ring closure after
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Published 21 Jun 2018

[3 + 2]-Cycloaddition reaction of sydnones with alkynes

  • Veronika Hladíková,
  • Jiří Váňa and
  • Jiří Hanusek

Beilstein J. Org. Chem. 2018, 14, 1317–1348, doi:10.3762/bjoc.14.113

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  • Veronika Hladikova Jiri Vana Jiri Hanusek Institute of Organic Chemistry and Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic 10.3762/bjoc.14.113 Abstract This review covers all known examples of [3 + 2]-cycloaddition between sydnones and both terminal as well
  • regioselectivity. Keywords: alkynes; Cu(I) catalysis; [3 + 2]-cycloaddition; mechanism; regioselectivity; sydnones; Review Introduction Since Huisgen’s discovery of the [3 + 2]-cycloaddition between 3-substituted sydnones and both terminal as well as internal alkynes [1][2] many researchers have tried to utilize
  • bicyclic intermediate via a concerted [3 + 2]-cycloaddition followed by its very fast decomposition (extrusion of CO2) via a retro-Diels–Alder [4 + 2]-cycloaddition. The almost spontaneous extrusion of CO2 is caused by an energetically favorable aromatization occurring in this step leading to the formation
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Published 05 Jun 2018

Mechanochemistry of nucleosides, nucleotides and related materials

  • Olga Eguaogie,
  • Joseph S. Vyle,
  • Patrick F. Conlon,
  • Manuela A. Gîlea and
  • Yipei Liang

Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81

Graphical Abstract
  • (Scheme 5) [42]. In the absence of light, azobenzene derivatives were isolated as the pure E-isomers. In their original report, Sharpless and co-workers described the use of copper turnings to promote a regioselective azide–alkyne [3 + 2]-cycloaddition ("click") reaction over 24 hours [43]. High-speed
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Published 27 Apr 2018

Addition of dithi(ol)anylium tetrafluoroborates to α,β-unsaturated ketones

  • Yu-Chieh Huang,
  • An Nguyen,
  • Simone Gräßle,
  • Sylvia Vanderheiden,
  • Nicole Jung and
  • Stefan Bräse

Beilstein J. Org. Chem. 2018, 14, 515–522, doi:10.3762/bjoc.14.37

Graphical Abstract
  • -dithioacetals [4] are of particular interest as attractive nucleophiles for the addition to halonium ions [5][6], acyl chlorides [7] and other electrophiles [8][9][10] and are broadly used as precursors for [2 + 2]-cycloaddition [11][12], (aza)-Diels–Alder reaction [13][14], and [3 + 2]-cycloaddition reactions
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Published 26 Feb 2018

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

  • Grzegorz Mlostoń and
  • Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221

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  • mechanisms. The in situ generated sterically crowded thiocarbonyl S-methanide 16b in dry THF undergoes a [3 + 2]-cycloaddition with both E- and Z-1b forming mixtures of diastereoisomeric thiolanes 19b [19] (Scheme 9). However, in all studied cases, the configuration of the starting dipolarophile was
  • - and Z-1b, and depending on the substitution pattern of the aziridine ring, the formation of the pyrrolidine derivative 34 occurred either with complete stereoselectivity or mixtures of isomeric products were obtained. The [3 + 2]-cycloaddition of the azomethine ylide E,Z-32a, formed via conrotatory
  • . Stepwise [3 + 2]-cycloadditions of dimethyl dicyanofumarate (E-1b) and dimethyl dicyanomaleate (Z-1b) with the in situ generated azomethine ylides 32. [3 + 2]-Cycloaddition of diazomethane with dimethyl dicyanofumarate (E-1b) leading to 1H-pyrazole derivative 36. Reversible Diels–Alder reaction of fulvenes
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Published 24 Oct 2017

Conjugated nitrosoalkenes as Michael acceptors in carbon–carbon bond forming reactions: a review and perspective

  • Yaroslav D. Boyko,
  • Valentin S. Dorokhov,
  • Alexey Yu. Sukhorukov and
  • Sema L. Ioffe

Beilstein J. Org. Chem. 2017, 13, 2214–2234, doi:10.3762/bjoc.13.220

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  • . Unfortunately, the reaction is complicated by a concurrent [3 + 2]-cycloaddition of diazo compounds 96 to nitrosoalkenes leading to N-nitrosopyrazoles 98 via intermediates 99. A substantial improvement of this isoxazoline ring-forming strategy was recently introduced by Li et al. [85], who achieved the
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Published 23 Oct 2017

A novel application of 2-silylated 1,3-dithiolanes for the synthesis of aryl/hetaryl-substituted ethenes and dibenzofulvenes

  • Grzegorz Mlostoń,
  • Paulina Pipiak,
  • Róża Hamera-Fałdyga and
  • Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 1900–1906, doi:10.3762/bjoc.13.185

Graphical Abstract
  • applied [14]. Another approach, which opens access to diverse ethenes, is the ‘two-fold extrusion reaction’, which comprises the [3 + 2]-cycloaddition of a diazo compound with a thiocarbonyl dipolarophile and subsequent elimination of N2 followed by sulfur extrusion [15][16][17]. In our continuing studies
  • unsuccessful. The results obtained with thiofluorenone (1c) prompted us to prepare other 2-trimethylsilylated 1,3-dithiolanes of type 6, available via [3 + 2]-cycloaddition of the in situ generated (at ca. −45 °C) silylated thiocarbonyl S-methanide 10 with thioketones 1a,c,d,h and i. The obtained products of
  • -trimethylsilyl-4,4,5,5-tetraaryl-1,3-dithiolanes, readily available by treatment of hetaryl thioketones with trimethylsilyl diazomethane (TMS-CHN2), are superior substrates for the preparation of tetraarylethenes. Another group of 2-trimethylsilylated 1,3-dithiolanes, obtained through the [3 + 2]-cycloaddition
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Published 08 Sep 2017

Ultrasound-promoted organocatalytic enamine–azide [3 + 2] cycloaddition reactions for the synthesis of ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones

  • Gabriel P. Costa,
  • Natália Seus,
  • Juliano A. Roehrs,
  • Raquel G. Jacob,
  • Ricardo F. Schumacher,
  • Thiago Barcellos,
  • Rafael Luque and
  • Diego Alves

Beilstein J. Org. Chem. 2017, 13, 694–702, doi:10.3762/bjoc.13.68

Graphical Abstract
  • other methods mostly provide the products in times above 60 minutes [33][34][36]. Conclusion In summary, we have described the use of sonochemistry in the organocatalytic enamine–azide [3 + 2] cycloaddition between 1,3-diketones and aryl azidophenyl selenides. These sonochemical promoted reactions were
  • Biotechnology of Natural and Synthetic Products, Universidade de Caxias do Sul, Caxias do Sul, RS, Brazil Departamento de Quimica Organica, Universidad de Cordoba, Campus de Rabanales, Cordoba, Spain 10.3762/bjoc.13.68 Abstract The use of sonochemistry is described in the organocatalytic enamine–azide [3 + 2
  • ] cycloaddition between 1,3-diketones and aryl azidophenyl selenides. These sonochemically promoted reactions were found to be amenable to a range of 1,3-diketones or aryl azidophenyl selenides, providing an efficient access to new ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones in good to excellent yields and
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Published 11 Apr 2017

Dimerization reactions of aryl selenophen-2-yl-substituted thiocarbonyl S-methanides as diradical processes: a computational study

  • Michael L. McKee,
  • Grzegorz Mlostoń,
  • Katarzyna Urbaniak and
  • Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 410–416, doi:10.3762/bjoc.13.44

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  • case of similar thiocarbonyl S-isopropanides, the intermediate zwitterions, formed in the course of the attempted [3 + 2]-cycloaddition with electron-deficient ethenes, undergo 1,3-electrocyclization yielding mixtures of stereoisomeric cyclopropanes in addition to the expected 5-membered thiolanes
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Published 03 Mar 2017

The reductive decyanation reaction: an overview and recent developments

  • Jean-Marc R. Mattalia

Beilstein J. Org. Chem. 2017, 13, 267–284, doi:10.3762/bjoc.13.30

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  • cyano group activates the [3 + 2] cycloaddition of azomethine ylides and is then removed to yield 5-unsubstituted pyrrolidines [74]. These substructures appear in several biologically active natural products and drugs [75]. A range of decyanation conditions were screened such as NaBH4 in THF or MeOH
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Published 13 Feb 2017

Multicomponent synthesis of spiropyrrolidine analogues derived from vinylindole/indazole by a 1,3-dipolar cycloaddition reaction

  • Manjunatha Narayanarao,
  • Lokesh Koodlur,
  • Vijayakumar G. Revanasiddappa,
  • Subramanya Gopal and
  • Susmita Kamila

Beilstein J. Org. Chem. 2016, 12, 2893–2897, doi:10.3762/bjoc.12.288

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  • stereospecific cyclic adducts. Keywords: L-proline; ninhydrin; sarcosine; spiropyrrolidine; 5-vinylindazole; 5-vinylindole; Introduction The [3 + 2] cycloaddition between azomethine ylides and olefins/acetylene as dipolarophiles is an important reaction to access a number of novel heterocyclic spiro scaffolds
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Published 29 Dec 2016

Combined experimental and theoretical studies of regio- and stereoselectivity in reactions of β-isoxazolyl- and β-imidazolyl enamines with nitrile oxides

  • Ilya V. Efimov,
  • Marsel Z. Shafikov,
  • Nikolai A. Beliaev,
  • Natalia N. Volkova,
  • Tetyana V. Beryozkina,
  • Wim Dehaen,
  • Zhijin Fan,
  • Viktoria V. Grishko,
  • Gert Lubec,
  • Pavel A. Slepukhin and
  • Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2016, 12, 2390–2401, doi:10.3762/bjoc.12.233

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  • -5-substituted isoxazoles that are otherwise difficult to obtain. Keywords: β-azolyl enamine; [3 + 2]-cycloaddition; isoxazole; isoxazoline; nitrile oxide; Introduction The biological activity and technically useful properties of isoxazoles have made them the focus of both medicinal and materials
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Published 15 Nov 2016

Stereoselective synthesis of fused tetrahydroquinazolines through one-pot double [3 + 2] dipolar cycloadditions followed by [5 + 1] annulation

  • Xiaofeng Zhang,
  • Kenny Pham,
  • Shuai Liu,
  • Marc Legris,
  • Alex Muthengi,
  • Jerry P. Jasinski and
  • Wei Zhang

Beilstein J. Org. Chem. 2016, 12, 2204–2210, doi:10.3762/bjoc.12.211

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  • , NH 03435, USA 10.3762/bjoc.12.211 Abstract The one-pot [3 + 2] cycloaddition of an azomethine ylide with a maleimide followed by another [3 + 2] cycloaddition of an azide with the second maleimide gives a 1,5-diamino intermediate which is used for a sequential aminomethylation reaction with
  • formaldehyde through [5 + 1] annulation to afford a novel polycyclic scaffold bearing tetrahydroquinazoline, pyrrolidine, pyrrolidinedione, and N-substituted maleimide in stereoselective fashion. Keywords: [5 + 1] annulation; [3 + 2] cycloaddition; one-pot reactions; stereoselective synthesis
  • new sequence initiated with a three-component [3 + 2] cycloaddition for preparing polycyclic scaffold 1 bearing tetrahydroquinazoline, pyrrolidine, pyrrolidinedione, and N-substituted maleimide rings. Those heterocyclic fragments could be found in bioactive compounds such as bromodomain, thrombin
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Published 18 Oct 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
  • , relatively high catalyst loadings (0.5–25 mol %) are required to achieve high yield and selectivities [15][45]. First, we investigated the catalytic asymmetric [3 + 2] cycloaddition of Schiff base 1a, prepared from glycine methyl ester and benzaldehyde, with N-phenylmaleimide (2a) in the presence of CuN
  • revealed that the reaction proceeded with 0.01 mol % loading of chiral CuHMDS catalyst without significant loss of selectivity (Table 1, entry 11). We then examined the substrate scope of the [3 + 2] cycloaddition with respect to the Schiff base (Table 2). The Schiff bases prepared from tolualdehydes were
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Published 13 Jul 2016

Synthesis of ferrocenyl-substituted 1,3-dithiolanes via [3 + 2]-cycloadditions of ferrocenyl hetaryl thioketones with thiocarbonyl S-methanides

  • Grzegorz Mlostoń,
  • Róża Hamera-Fałdyga,
  • Anthony Linden and
  • Heinz Heimgartner

Beilstein J. Org. Chem. 2016, 12, 1421–1427, doi:10.3762/bjoc.12.136

Graphical Abstract
  • 1,5-diradical as a key intermediate. The complete change of the reaction mechanism toward the concerted [3 + 2]-cycloaddition was observed in the reaction of a sterically crowded cycloaliphatic thiocarbonyl ylide with ferrocenyl methyl thioketone. Keywords: [3 + 2]-cycloadditions; 1,3-dithiolanes
  • Hz. After chromatographic purification, the 13C NMR spectrum confirmed the 5-CH2-type of the 1,3-dithiolane 6m, as the corresponding CH2 absorption was found at 52.5 ppm (Scheme 3). Based on our earlier interpretation of the reaction mechanism leading to 1,3-dithiolanes via [3 + 2]-cycloaddition of
  • key-intermediates in the reaction. On the other hand, the formation of 1,3-dithiolanes of type 5 in reactions with cycloaliphatic thiocarbonyl S-methanides competes with the concerted [3 + 2]-cycloaddition leading to the sterically less crowded 1,3-dithiolanes 6 (Scheme 2). These results demonstrate
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Published 08 Jul 2016

Synergistic chiral iminium and palladium catalysis: Highly regio- and enantioselective [3 + 2] annulation reaction of 2-vinylcyclopropanes with enals

  • Haipan Zhu,
  • Peile Du,
  • Jianjun Li,
  • Ziyang Liao,
  • Guohua Liu,
  • Hao Li and
  • Wei Wang

Beilstein J. Org. Chem. 2016, 12, 1340–1347, doi:10.3762/bjoc.12.127

Graphical Abstract
  • enals and a transition metal promoting to open the 2-vinylcyclopropanes for highly regio- and enantioselective [3 + 2] cycloaddition reaction of 2-vinylcyclopropanes with α,β-unsaturated aldehydes has been developed. Keywords: [3 + 2] annulation; enals; synergistic catalysis; vinylcyclopropanes
  • ; Introduction The power of “donor–acceptor” (D–A) cyclopropanes as versatile 1,3-dipolar components is fuelled by its capacity of serving a complementary approach to a wide array of 5-membered ring structures, which are difficult or impossible to access by classic [3 + 2] cycloaddition reactions [1][2][3][4][5
  • due to the minimization of the A[1][3] interaction. Therefore, it is observed 3a’ produced from corresponding 8a’ as the major diastereomer whereas 3a” as minor one. Conclusion We have developed a cooperative catalytic strategy for highly regio- and enantioselective [3 + 2] cycloaddition reactions of
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Published 29 Jun 2016

Copper-catalyzed [3 + 2] cycloaddition of (phenylethynyl)di-p-tolylstibane with organic azides

  • Mizuki Yamada,
  • Mio Matsumura,
  • Yuki Uchida,
  • Masatoshi Kawahata,
  • Yuki Murata,
  • Naoki Kakusawa,
  • Kentaro Yamaguchi and
  • Shuji Yasuike

Beilstein J. Org. Chem. 2016, 12, 1309–1313, doi:10.3762/bjoc.12.123

Graphical Abstract
  • clarity. Two independent molecules exist in the asymmetric unit, one of them is shown. Copper-catalyzed [3 + 2] cycloaddition of 1 with organic azides 2. Reaction conditions: 1 (0.5 mmol), 2a (0.5 mmol), Cu cat. (0.025 mmol). Isolated yield are shown. Possible mechanism. Reaction of 3a with HCl, I2 and
  • University, 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan Faculty of Pharmaceutical Sciences, Hokuriku University, Ho-3 Kanagawa-machi, Kanazawa 920-1181, Japan 10.3762/bjoc.12.123 Abstract Trisubstituted 5-stibano-1H-1,2,3-triazoles were synthesized in moderate to excellent yields by the Cu-catalyzed [3 + 2
  • ] cycloaddition of a ethynylstibane with organic azides in the presence of CuBr (5 mol %) under aerobic conditions. The reaction of 5-stibanotriazole with HCl, I2, and NOBF4 afforded 1-benzyl-4-phenyltriazole, 1-benzyl-5-iodo-4-phenyltriazole, and a pentavalent organoantimony compound, respectively. Keywords
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Published 23 Jun 2016
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