Imino Ene Reaction Research Articles

Enantioselective Imino-Ene Reaction of N-Sulfonyl Ketimines with Silyl Enol Ethers: Access to Chiral Benzosultams.

A highly efficient asymmetric imino-ene reaction of cyclic ketimines with silyl enol ethers was developed. Various chiral benzosultam derivatives were obtained in excellent yields (up to 99%), enantioselectivities (up to 99% ee), and diastereoselectivities (up to >19:1 dr) by utilizing a Ni(BF4)2·6H2O/N,N'-dioxide complex as the catalyst. A possible transition state model was proposed to explain the stereoinduction. Furthermore, the synthetic utility of the protocol provided quick access to optically pure HIV-1 inhibitor.

Intramolecular Imino-ene Reaction of Azirines: Regioselectivity, Diastereoselectivity, and Computational Insights.

Intramolecular imino-ene reaction of 2 H-aziridine has been studied experimentally and computationally, demonstrating that (1) the concerted process takes place regioselectively on the alkene E-CH group; (2) the geometry of the N-linker impacts the reaction activation energy and diastereoselectivity significantly, with pyramidal alkyl amine as the linkage, an exclusive cis-product is achieved; (3) when the reaction has to occur with the Z-CH group, the cis-diastereoselectivity is solely observed regardless of the nature of the N-linkage.

Intramolecular Imino-ene Reaction of 2H-azirines with Alkenes: Rapid Construction of Spiro NH Aziridines from Vinyl Azides

A range of novel (poly)cyclic alkaloids incorporating an unprecedented 1,5-diazaspiro[2.4]heptane core that carry a spiro NH aziridine moiety and a 7-vinyl group are constructed from the thermal reaction of vinyl azides with tethered alkenes. Vinyl azides are converted to 2H-azirines in situ, which serve as enophiles for intramolecular imino-ene reactions with suitable alkenes. High stereoselectivity and specificity have been achieved for this novel intramolecular imino-ene reaction of azirines.

Phosphoric Acid Catalyzed [4+2] Cycloadditions and Imino–Ene Reactions

Phosphoric Acid Catalyzed [4+2] Cycloadditions and Imino–Ene Reactions

Perfluorinated Aryls in the Design of Chiral Brønsted Acid Catalysts: Catalysis of Enantioselective [4 + 2] Cycloadditions and Ene Reactions of Imines with Alkenes by Chiral Mono-Phosphoric Acids with Perfluoroaryls

Perfluorinated aryl-incorporating chiral monophosphoric acids were used for highly stereoselective reactions of N-acyl and N-acyloxy aldimines with styrenes. Their electronic and steric profiles were established in comparison with those of phenyl, binaphthyl, and partially fluorinated aryls. The [4 + 2] cycloaddition reactions of N-benzoyl aldimines with alkenes proceeded with excellent diastereo- and enantioselectivities in the presence of the perfluorophenyl-incorporating chiral monophosphoric acid catalysts 1a and 1c. The stereoselective elaboration of polysubstituted cycloadducts to amines is described. The imino–ene reactions of N-Fmoc imines with alkenes have been successfully developed in a three-component manner. This process uses aldehydes, 9-fluorenylmethyl carbamate, and alkenes in the presence of a chiral monophosphoric acid catalyst, 2a, possessing an F10binaphthyl skeleton.

Synthetic Method for 2,2'-Disubstituted Fluorinated Binaphthyl Derivatives and Application as Chiral Source in Design of Chiral Mono-Phosphoric Acid Catalyst.

A practical synthetic method for 2,2'-disubstituted fluorinated binaphthyl derivatives was achieved using magnesium bis(2,2,6,6-tetramethylpiperamide) [Mg(TMP)(2)], prepared from LiTMP (2 equiv) and MgBr(2) (1 equiv), which allows for access to a variety of fluorinated binaphthyl compounds. The utility of the fluorinated binaphthyl backbone was evaluated in F10 BINOL derived chiral mono-phosphoric acid (R)- as the chiral Brønsted acid catalyst. The catalyst (R)- performs exceptionally well in the catalytic enantioselective imino-ene reaction, demonstrating the potential of a fluorinated binaphthyl framework.

ChemInform Abstract: Advancements in Catalytic Asymmetric Intermolecular Ene‐Type Reactions

AbstractReview: [56 refs.

Advancements in Catalytic Asymmetric Intermolecular Ene-Type Reactions

Correction to: Advancements in Catalytic Asymmetric Intermolecular Ene-Type ReactionsSynthesis 2014; 46(17): 2241-2257DOI: 10.1055/s-0034-1378528

Lewis Acid Catalyzed Intramolecular Direct Ene Reaction of Indoles

Indoles bearing a tethered internal olefin smoothly undergo a highly efficient diastereoselective intramolecular imino-ene reaction in the presence of AlCl3 to give cycloalkano-fused indolines, e.g. (II), (IV) or (VI), in high yields and stereoselectivities.

ChemInform Abstract: New Type of Intramolecular Imino-Ene Cyclization During Pyrolysis of (- )-Cocaine.

Abstract Pyrolysis of (−)-cocaine resulted in an uprecedented, complex sequence of reactions, including a new type of imino-ene reaction.

ChemInform Abstract: Ytterbium(III) Triflate/TMSCI: Efficient Catalyst for Imino Ene Reaction.

[reaction: see text] Ytterbium trifluoromethanesulfonate [Yb(OTf)3] catalyzed the imino ene reaction of N-tosyl aldimine with alpha-methylstyrene to give a homoallylamine in moderate yield. Furthermore, addition of a catalytic amount of chlorotrimethylsilane (TMSCI) dramatically enhanced the imino ene reaction.

Brønsted acid promoted imino-ene reactions

A series of all-carbon olefins react with glyoxylate derived imines in the presence of a phosphonic acid through an ene reaction. The isolation of the α-aminoester products is a clear indication that Brønsted acids efficiently promote the imino-ene reaction with hydrocarbon nucleophiles to deliver functionalized α-aminoesters in good yield. The reaction scope and preliminary mechanistic investigations are discussed.

Copper‐Catalyzed Transformation of Carbonyl‐ene‐nitrile Compounds: Vinylation, Imino Ene Reaction, and Alkynylation of 2‐Aza‐2,4‐cyclopentadienone Intermediates Generated via Ritte‐Type Hydration and Dehydrative Cyclization Reactions.

AbstractChemInform 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.

Copper-catalyzed transformation of carbonyl-ene-nitrile compounds: Vinylation, imino ene reaction, and alkynylation of 2-aza-2,4-cyclopentadienone intermediates generated via Ritter-type hydration and dehydrative cyclization reactions

1 H-pyrrolin-2(5 H)-one derivatives are easily obtained from carbonyl-ene-nitrile compounds and alkenes or alkynes by copper(II)-catalyzed tandem sequence involving vinylation or allylation as well as Ritter-type hydration and dehydrative cyclization.

Imino‐ene Reaction of N‐Tosyl Arylaldimines with α‐Methylstyrene: Application in the Synthesis of Important Amines.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Imino-ene reaction of N-tosyl arylaldimines with α-methylstyrene: application in the synthesis of important amines

Copper(II) or tin(II) trifluoromethanesulfonate in combination with TMSCl effectively activates a C–H bond for the imino-ene reaction of N-tosylarylaldimines with α-methylstyrene. A wide variety of N-tosylarylaldimines were used to give homoallylamines in good to excellent yields under mild conditions. The imino-ene adduct was converted into a β-amino ketone. The synthesis of a 2,4-substituted pyrrolidine and a piperidine was also achieved from the imino-ene product via a Mitsunobu reaction and a Grubbs cyclization, respectively.

Heterogeneous Enantioselective Catalyzed Carbonyl- and Imino-Ene Reactions using Copper Bis(Oxazoline) Zeolite Y

En-thusiastisch: Die ersten heterogen katalysierten enantioselektiven Carbonyl-En- und Imino-En-Reaktionen bieten einfache Alternativen zur Synthese von α-Hydroxy- und α-Aminocarbonylverbindungen mit hohen Ausbeuten und Enantioselektivitäten. Als Katalysator dient ein Bis(oxazolin)-modifiziertes CuH-Zeolith-Y(Cu-HY)-System (siehe Schema; Rox=CH3, H; Rbrg=Ph, C(CH3)3), das leicht zurückgewonnen werden kann.

Heterogeneous enantioselective catalyzed carbonyl- and imino-ene reactions using copper bis(oxazoline) zeolite Y.

A recovery discovery: A simple pathway for the synthesis of α-hydroxy and α-amino carbonyl compounds with good yields and high enantioselection is provided by the first heterogeneously catalyzed enantioselective carbonyl-ene and imino-ene reactions. The catalyst is a bis(oxazoline)-modified CuH zeolite Y (Cu-HY)system (see scheme; Rox=CH3,H; Rbrg=Ph,C(CH3)3), which can easily be recovered and reused.

Imino Ene Reaction Catalyzed by Ytterbium(III) Triflate and TMSCl or TMSOTf.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthetic Study of Biologically Important Nitrogen Containing Natural Products: Development of New Methodology and Design of Leading Compounds for New Pharmaceuticals

AbstractFor Abstract see ChemInform Abstract in Full Text.