Kinugasa Reaction Research Articles

A Highly Stereoselective Synthesis of Chiral α-Amino-β-lactams via the Kinugasa Reaction Employing Ynamides

A highly stereoselective synthesis of chiral alpha-amino-beta-lactam through an ynamide-Kinugasa reaction is described. In addition, a mechanistic model is illustrated here to rationalize the observed diastereoselectivity, which depends on both the initial [3 + 2] cycloaddition step and the subsequent protonation for which both are highly selective.

Synthesis of β‐Lactams Using the Kinugasa Reaction

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The Synthesis of Heterocycles Using Cascade Chemistry

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.

Kinugasa Reaction under Click Chemistry Conditions.

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.

Synthesis of β-Lactams Using the Kinugasa Reaction

The development of new strategies for the synthesis of β-lactams and their derivatives remains at the forefront of organic synthesis. The copper(I)-catalyzed cycloaddition of a terminal alkyne and a nitrone, the Kinugasa reaction, leading to the formation of a β-lactam has recently drawn to the attention of organic chemists because of its wide scope as well as interesting mechanism. This report aims to give an account of developments in this area with particular emphasis on asymmetric examples.

The Asymmetric Synthesis of β‐Lactams: HETPHOX/Cu(I) Mediated Synthesis via the Kinugasa Reaction.

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.

Kinugasa Reaction under Click Chemistry Conditions

Various monocyclic β-lactams, both cis and trans, have been successfully prepared via Kinugasa reaction mimicking the click chemistry conditions.

The asymmetric synthesis of β-lactams: HETPHOX/Cu(I) mediated synthesis via the Kinugasa reaction

The reactions of nitrones with terminal alkynes, catalysed by a range of HETPHOX ligands afforded β-lactams in moderate to good conversions with ees up to 55%. High levels of diastereoselectivity, dependent on the alkyne, were obtained. For example, the reaction is highly cis-diastereoselective with phenylacetylene (>9:1), while an unexpected reversal of diastereoselectivity is observed with the 3,5-trifluoromethyl phenylacetylene, which is highly trans selective (1:9) with an ee of 53%. The reaction scope with differently substituted nitrones and phenylacetylenes was also studied.

A Novel Synthesis of β‐Lactam Fused Cyclic Enediynes by Intramolecular Kinugasa Reaction.

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.

Trisoxazoline/Cu(II)‐Promoted Kinugasa Reaction. Enantioselective Synthesis of β‐Lactams.

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.

Trisoxazoline/Cu(II)-Promoted Kinugasa Reaction. Enantioselective Synthesis of β-Lactams

The reactions of nitrones with terminal alkynes, catalyzed by chiral (i)Pr-trisoxazoline 2a/Cu(ClO4)2.6H2O under air atmosphere, afforded beta-lactams in moderate to good yields with up to 85% ee. The diastereoselectivity depends on the alkyne. Propiolate gives the trans-isomer as a major product, while the other alkynes afford cis-disubstituted lactams predominantly. Copper(II) salt proved to be an efficient catalyst precursor for the first time in the Kinugasa reaction, and this allowed the reaction to be performed under a practical and convenient condition. An appropriate base used in this reaction was essential to control both diastereoselectivity and enantioselectivity. Compared with primary and tertiary amines, secondary amines gave higher enantioselectivities. The reaction scope and limitation as well as the mechanism were also studied.

A novel synthesis of β-lactam fused cyclic enediynes by intramolecular Kinugasa reaction

A general synthetic route to beta-lactam-fused enediynes by intramolecular Kinugasa reaction has been successfully developed. The method has widened the scope of Kinugasa reaction in the synthesis of sensitive systems like the one described in this communication.

The Discovery of Novel Metal‐Induced Reactions of Nitrones: Not Only Electrophiles and Reagents for [3+2] Cycloadditions

In the last few years a multitude ofnovel reactions involving nitrones havebeendiscoveredwhichyieldstructurallydiverseandhighlyfunctionalizedusefulproducts. Most of the new C C bond-formingreactionshavebeeneffectedbytheuseofmetalderivatives,whichalterthe usual nitrone reactivity. The reac-tions which showed broader scope andpotential, and have already witnesseduseful synthetic application, are twometal-mediated cycloadditions, namelya formal [2+2] (the Kinugasa reaction,which affords b-lactam derivatives andhas recently been reviewed)

Synthesis of β‐Lactam Nucleoside Chimera via Kinugasa Reaction and Evaluation of Their Antibacterial Activity.

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Synthesis of β-lactam nucleoside chimera via Kinugasa reaction and evaluation of their antibacterial activity

Several β-lactam nucleoside chimeras 1 ( cis) and 2 ( trans) were synthesized from the corresponding N-propargyl nucleobases via Kinugasa reaction in moderate yields. Initial screening for antibacterial activity against ampicillin sensitive E. coli showed weak activity for the uracil-β-lactam chimera.

L‐Proline‐Mediated One‐Pot Synthesis of 3‐Exomethylene β‐Lactams via Kinugasa Reaction.

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β‐Lactam Synthesis by the Kinugasa Reaction

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Beta-Lactam synthesis by the Kinugasa reaction.

A renaissance in β-lactam synthesis was sparked by recent reports on the Kinugasa reaction, including asymmetric versions like that shown. Owing to the biological activity of the heterocycles and their utility in synthesis, these methods have attracted much attention.

L-Proline-Mediated One-Pot Synthesis of 3-Exomethylene β-Lactams via Kinugasa Reaction

Synthetically important 3-exomethylene β-lactams 4a-f were obtained in a single step via Cu(I)-mediated cycloaddition between propargyl alcohol/butyn-2-ol and nitrones 2a-d, in the nresence of L-proline (Kinugasa reaction).

Catalytic Enantioselective Synthesis of β‐Lactams: Intramolecular Kinugasa Reactions and Interception of an Intermediate in the Reaction Cascade.

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