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Dipolar Cycloaddition (dipolar + cycloaddition)

Distribution by Scientific Domains
Chemistry100%

Terms modified by Dipolar Cycloaddition

  • dipolar cycloaddition reaction
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    Selected Abstracts

    Unusual Cycloadducts from the Dipolar Cycloaddition of Allenyl Perfluoroalkyl Sulfones to Nitrones.

    CHEMINFORM, Issue 37 2007
    Xiao-Jin Wang
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    Dipolar Cycloaddition of Carbonyl Ylides to 2-Oxoindolinylidenes: A Facile Approach Towards the Synthesis of Functionalized Spiroindolenins.

    CHEMINFORM, Issue 6 2003
    Vijay Nair
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Unusual Cycloadducts from the Dipolar Cycloaddition of Allenyl Perfluoroalkyl Sulfones to Nitrones

    CHINESE JOURNAL OF CHEMISTRY, Issue 5 2007
    Xiao-Jin Wang
    Abstract The dipolar cycloaddition reaction of allenyl perfluoroalkyl sulfones (1) to nitrones (2) was described. Unlike nonfluorine-containing allenyl sulfones, 1 reacted readily with 2 in ether at room temperature and unusual zwitterionic cycloadducts (3) were obtained in good yields due to the strong electron-withdrawing effect of perfluoroalkyl groups. The structure of 3 was characterized by spectral analyses and X-ray crystallography. [source]

    Reactivity and X-ray Structural Studies in Ligand Substitution of [Cp/(Ind)Ru(dppf)Cl] , Epimerisation in [Cp/(Ind)Ru(Josiphos)Cl] {Cp = ,5 -C5H5, Ind = ,5 -C7H9, dppf = 1,1,-Bis(diphenylphosphanyl)ferrocene, Josiphos = (R)-(,)-1-[(S)-2-(Diphenylphosphanyl)ferrocenyl]ethyldicyclohexylphosphane}

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 3 2007
    Sin Yee Ng
    Abstract Ligand substitution of [(Ind)Ru(PPh3)2Cl] (1) led to the isolation of [(Ind)Ru(PPh3){Ph2P(CH2)2C9H7}Cl] (2), [(Ind)Ru(dppf)Cl] (3) and [(Ind)Ru{(Ph2PCH2)3CMe}]PF6 ([4]PF6), and diastereoisomers [(R)- and (S)-(Ind)Ru(Josiphos)Cl] [(R)- 5 and (S)- 5], where (R)-(S)-Josiphos is the ferrocene-based chiral diphosphane ligand (R)-(,)-1-[(S)-2-(diphenylphosphanyl)ferrocenyl] ethyldicyclohexylphosphane. The Cp analogues of 5, viz. (R)- 6 and (S)- 6, were also obtained from [CpRu(PPh3)2Cl] (1a). Josiphos-dependent epimerisation was observed, with conversion of the (S) isomer to the (R) isomer in both cases. Chloride abstraction of 3 with NaPF6 in CH3CN and NaN3 in EtOH gave [(Ind)Ru(dppf)(CH3CN)]PF6 ([7]PF6) and [(Ind)Ru(dppf)(N3)] (8), respectively. The azido ligand in 8 underwent [3+2] dipolar cycloaddition with dimethyl acetylenedicarboxylate to give a N -bound bis(methoxycarbonyl)-1,2,3-triazolato complex, 9. X-ray crystal structures of the new complexes, except (R)- 5, (S)- 5 and (S)- 6, have been determined. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

    ChemInform Abstract: Synthesis and hSERT Activity of Homotryptamine Analogues.

    CHEMINFORM, Issue 39 2010
    Part 6. [3 + 2] Dipolar Cycloaddition of 3-Vinylindoles.
    Abstract A series of homotryptamine analogues such as (V) and (VIII) is prepared via [3 + 2] dipolar cycloaddition of vinylindole (I) with cyclic nitrones as key step. [source]

    Organocatalytic and Stereoselective [3 + 2] Cycloadditions of Azomethine Imines with ,,,-Unsaturated Aldehydes

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14 2006
    Wei Chen
    Abstract Bipyrazolidin-3-one derivatives are biologically significant compounds and their importance has increased in the past decades. In this paper, the first stereoselective [3 + 2] dipolar cycloadditions of azomethine imines with ,,,-unsaturated aldehydes catalyzed by readily available ,,,-diarylprolinol salts are reported, providing a facile route to the synthesis of various chiral bipyrazolidin-3-one derivatives under mild conditions. The organocatalyst 1,g with strongly electron-withdrawing groups exhibited the best stereoselectivity (exo:endo up to 98:2, for exo product up to 97,% ee), in the combination with trifluoroacetic acid. [source]