Results 21 to 30 of about 88,292,358 (173)
Arylthio-substituierte Nitrilylide aus der Thermolyse von 4-Arylthio-3-oxazolin-5-onen
CHIMIA, 1984 Thermolysis of 4-arylthio- and 4-benzylthio-3-oxazolin-5-ones leads to arylthio- and benzylthio-substituted nitrile ylides, which undergo 1,3-dipolar cycloadditions with reactive dipolarophiles to give 5-membered aza-heterocycles (Schemes 1 and 2).
Peter Wipf, Heinz Heimgartner
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Molecules, 2020 We present herein a straightforward and efficient pathway for the synthesis of pyrrolophthalazine cycloadducts via Huisgen [3 + 2] dipolar cycloaddition reactions of phthalazinium ylides to methyl propiolate or dimethyl acetylenedicarboxylate (DMAD).
Vasilichia Antoci +4 more
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Nature Communications, 2021 The bridged medium-sized ring bicyclo[m.n.2] family of natural products are commonly found but difficult to synthesize efficiently. Here the authors present a cascade reaction to form the carbon skeleton, via a [3+2] cycloaddition of a captured azavinyl ...
Bao-Long Hou +5 more
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1,3-Dipolar cycloadditions of 2-thio-3-chloroacrylamides with nitrile oxides and nitrones [PDF]
, 2010 1,3-Dipolar cycloadditions of 2-thio-3-chloroacrylamides with nitrile oxides and nitrones is described. A series of novel isoxazolines are isolated from the nitrile oxide cycloadditions, whilst the isoxazolines generated from the nitrone cycloadditions ...
Lawrence, Simon E. +2 more
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Asymmetric 1,3-dipolar cycloadditions of acrylamides [PDF]
, 2009 This critical review, which is relevant to researchers in synthetic organic chemistry, focuses on asymmetric 1,3-dipolar cycloadditions with acrylamides.
Kissane, Marie, Maguire, Anita R.
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Asymmetric 1,3-Dipolar Cycloadditions to 5-Menthyloxy-2[5H]-furanones. [PDF]
, 1988 Cycloadditions of various 1,3-dipolar reagents to chiral butenolides 1 and 5 proceed with diastereomeric excess of 20-100%.
Lange, Ben de +3 more
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1, 3-Dipolar Cycloadditions. LXXVI. Cycloadditions of Diazomethane to Substituted Butadienes
Chemical and Pharmaceutical Bulletin, 1975 1-Substituted butadienes (R=CH2, CH3, O, C3H5, CO2CH3, CN) and 2-phenylbutadiene accept diazomethane at the 3, 4-bond yielding 3-vinylpyrazoline derivatives. Tautomerization of the 1-to 2-pyrazolines takes place either at room temperature (R=CO2CH3, CN), on heating (R=C6H5) or on acid catalysis (R=H, CH3, OCH3) ; the 2-pyrazolines are characterized as ...
HUISGEN, ROLF +2 more
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Synthesis of novel pyrazoles via [2+3]-dipolar cycloaddition using alkyne surrogates [PDF]
Tetrahedron Letters, 2010 The syntheses of an important class of hitherto unreported novel pyrazoles are described. The regioselective synthesis of 1,3,4,5-tetrasubstituted pyrazoles was achieved by the Huisgen cyclization of nitrile imines with a trisubstituted bromoalkene. The substituted bromoalkene functions as an alkyne synthon which was used to construct 5,5-disubstituted
Sureshbabu, Dadiboyena +2 more
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Molecules, 2015 Over the last several years there has been a huge increase in the development and applications of new efficient organocatalysts for enantioselective pericyclic reactions, which represent one of the most powerful types of organic transformations.
Felix E. Held +2 more
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Beilstein Journal of Organic Chemistry, 2014 1,3-Dipolar cycloadditions of isatins, benzylamine and benzylideneacetones were studied to prepare a series of novel spiropyrrolidine-oxindoles – 4′-acetyl-3′,5′-diarylspiro[indoline-3,2′-pyrrolidin]-2-ones and 3′-acetyl-4′,5′-diarylspiro[indoline-3,2 ...
Chuqin Peng +5 more
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