Structure and Additive-free Transamidation of Planar <i>N</i>-Cyano Amides

Yamasaki, Ryu; Okada, Yuko; Iizumi, Hiromi; Ito, Ai; Fukuda, Kazuo; Okamoto, Iwao

doi:10.1021/acs.joc.3c00172

Cited by 5 publications

(1 citation statement)

References 46 publications

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“…In the case of the secondary anilides, such as acetanilide ( 1 ), they generally favor the trans conformer, whereas N -methylated tertiary amides tend to adopt the cis conformer . This cis conformational preference of tertiary amides is mainly explained by the electronic repulsion between carbonyl and twisted phenyl group, caused by the “magic methyl” effect on amide nitrogen, in the trans conformer. , N -Ethynyl and cyano acetanilides ( 3a and 3b ) favor the trans conformer to avoid triple bond-carbonyl electrostatic repulsion, whereas their N -vinyl surrogates favor the cis conformation to avoid alkene-carbonyl repulsion through an s-trans N–C(=C) rotamer . However, the effects of substitution on the alkene moiety remain to be explored in detail.…”

Section: Introductionmentioning

confidence: 99%

Structures and Reactivities of N-Alkenyl-Substituted Anilides: The “Magic” Methyl Effect on Alkene

Yamasaki,

Ono,

Morita

et al. 2023

J. Org. Chem.

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Methyl substitution at the double bond of N-alkenyl anilides influences both the preferred conformation and the susceptibility to acidic hydrolysis. The R 1 -substituted amide favors the trans conformation, whereas amides substituted at R 2 or R 3 favor the cis conformation. Substitution at the R 1 and R 3 positions increases the ratio of the trans conformer. DFT study indicated that these conformational preferences can be explained in terms of substituent-induced torsion twisting of the N-alkenyl moiety relative to the amide plane. R 1 substitution enhances the susceptibility to acidic hydrolysis, whereas R 2 or R 3 substitution increases the stability. The effect of the double bond on the conformational effect was showcased by contrasting the preferred conformation of R 1 -substituted anilide (trans) and hydrogenated N-isopropyl amide (cis).

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Section: Introductionmentioning

confidence: 99%

Structures and Reactivities of N-Alkenyl-Substituted Anilides: The “Magic” Methyl Effect on Alkene

Yamasaki,

Ono,

Morita

et al. 2023

J. Org. Chem.

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Molecular Oxygen‐Induced Transamidation of Unactivated Amides in Diethyl Carbonate in the Presence of a Palladium Catalyst

Urgoitia,

Obieta,

Herrero

et al. 2023

Adv Synth Catal

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Herein we disclose a palladium‐catalyzed procedure for the transamidation of structurally diverse amides with amines based on the use of molecular oxygen as palladium‐activating agent. The reaction, which is scalable and amenable for the preparation of enantioenriched compounds, is carried out in a bio‐degradable solvent often used as a fuel additive, diethyl carbonate. As a result of 10‐4 mol% of catalyst required, final products are isolated containing palladium impurities in a concentration of 0.1 ppm. Two kinetically different mechanistic pathways are proposed for this reaction on account of a number of experiments such as kinetic curves, TEM images, catalyst poisoning experiments, UPLC‐ESI‐MS identification of intermediates and EPR spectra of reaction crude.

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Palladium-Catalyzed Chelation-Assisted Aldehyde C–H Bond Activation of Quinoline-8-carbaldehydes: Synthesis of Amides from Aldehydes with Anilines and Other Amines

Thakur,

Rathod,

Patel

et al. 2024

J. Org. Chem.

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A palladium-catalyzed chelation-assisted direct aldehyde C−H bond amidation of quinoline-8-carbaldehydes with an amine was developed under mild reaction conditions. A wide range of amides were obtained in good to excellent yields from aldehyde with a variety of aniline derivatives and aliphatic amines. Our methodology was successfully applied to synthesize known DNA intercalating agents and can be easily scaled up to a gram scale.

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Structure and Additive-free Transamidation of Planar N-Cyano Amides

Cited by 5 publications

References 46 publications

Structures and Reactivities of N-Alkenyl-Substituted Anilides: The “Magic” Methyl Effect on Alkene

Structures and Reactivities of N-Alkenyl-Substituted Anilides: The “Magic” Methyl Effect on Alkene

Molecular Oxygen‐Induced Transamidation of Unactivated Amides in Diethyl Carbonate in the Presence of a Palladium Catalyst

Palladium-Catalyzed Chelation-Assisted Aldehyde C–H Bond Activation of Quinoline-8-carbaldehydes: Synthesis of Amides from Aldehydes with Anilines and Other Amines

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