N−C Axially Chiral Anilines: Electronic Effect on Barrier to Rotation and A Remote Proton Brake

Yumiko Iwasaki; Ryuichi Morisawa; Satoshi Yokojima; Hiroshi Hasegawa; Christian Roussel; Nicolas Vanthuyne; Elsa Caytan; Osamu Kitagawa

doi:10.1002/chem.201706115

N−C Axially Chiral Anilines: Electronic Effect on Barrier to Rotation and A Remote Proton Brake

Yumiko Iwasaki, Ryuichi Morisawa, Satoshi Yokojima, Hiroshi Hasegawa, Christian Roussel, Nicolas Vanthuyne, Elsa Caytan, Osamu Kitagawa

Research output: Contribution to journal › Article › peer-review

20 Citations (Scopus)

Abstract

N-Aryl-N-methyl-2-tert-butyl-6-methylaniline derivatives exhibit a rotationally stable N−C axially chiral structure and the rotational barriers around an N−C chiral axis increased with the increase in electron-withdrawing character of para-substituent on the aryl group. X-ray crystal structural analysis and the DFT calculation suggested that the considerable change of the rotational barriers by the electron effect of para-substituents is due to the disappearance of resonance stabilization energy caused by the twisting of para-substituted phenyl group in the transition state. This structural property of the N−C axially chiral anilines was employed to reveal a new acid-decelerated molecular rotor caused by the protonation at the remote position (remote proton brake).

Original language	English
Pages (from-to)	4453-4458
Number of pages	6
Journal	Chemistry - A European Journal
Volume	24
Issue number	17
DOIs	https://doi.org/10.1002/chem.201706115
Publication status	Published - 2018 Mar 20

Keywords

amines
axial chirality
density functional calculations
electronic effect
proton brake

ASJC Scopus subject areas

Catalysis
Organic Chemistry

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10.1002/chem.201706115

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@article{f60bdce135fc4c89923e72506aa2cee9,

title = "N−C Axially Chiral Anilines: Electronic Effect on Barrier to Rotation and A Remote Proton Brake",

abstract = "N-Aryl-N-methyl-2-tert-butyl-6-methylaniline derivatives exhibit a rotationally stable N−C axially chiral structure and the rotational barriers around an N−C chiral axis increased with the increase in electron-withdrawing character of para-substituent on the aryl group. X-ray crystal structural analysis and the DFT calculation suggested that the considerable change of the rotational barriers by the electron effect of para-substituents is due to the disappearance of resonance stabilization energy caused by the twisting of para-substituted phenyl group in the transition state. This structural property of the N−C axially chiral anilines was employed to reveal a new acid-decelerated molecular rotor caused by the protonation at the remote position (remote proton brake).",

keywords = "amines, axial chirality, density functional calculations, electronic effect, proton brake",

author = "Yumiko Iwasaki and Ryuichi Morisawa and Satoshi Yokojima and Hiroshi Hasegawa and Christian Roussel and Nicolas Vanthuyne and Elsa Caytan and Osamu Kitagawa",

note = "Funding Information: This work was partly supported by JSPS (C17K08220). Publisher Copyright: {\textcopyright} 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim",

year = "2018",

month = mar,

day = "20",

doi = "10.1002/chem.201706115",

language = "English",

volume = "24",

pages = "4453--4458",

journal = "Chemistry - A European Journal",

issn = "0947-6539",

publisher = "Wiley-VCH Verlag",

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TY - JOUR

T1 - N−C Axially Chiral Anilines

T2 - Electronic Effect on Barrier to Rotation and A Remote Proton Brake

AU - Iwasaki, Yumiko

AU - Morisawa, Ryuichi

AU - Yokojima, Satoshi

AU - Hasegawa, Hiroshi

AU - Roussel, Christian

AU - Vanthuyne, Nicolas

AU - Caytan, Elsa

AU - Kitagawa, Osamu

PY - 2018/3/20

Y1 - 2018/3/20

N2 - N-Aryl-N-methyl-2-tert-butyl-6-methylaniline derivatives exhibit a rotationally stable N−C axially chiral structure and the rotational barriers around an N−C chiral axis increased with the increase in electron-withdrawing character of para-substituent on the aryl group. X-ray crystal structural analysis and the DFT calculation suggested that the considerable change of the rotational barriers by the electron effect of para-substituents is due to the disappearance of resonance stabilization energy caused by the twisting of para-substituted phenyl group in the transition state. This structural property of the N−C axially chiral anilines was employed to reveal a new acid-decelerated molecular rotor caused by the protonation at the remote position (remote proton brake).

AB - N-Aryl-N-methyl-2-tert-butyl-6-methylaniline derivatives exhibit a rotationally stable N−C axially chiral structure and the rotational barriers around an N−C chiral axis increased with the increase in electron-withdrawing character of para-substituent on the aryl group. X-ray crystal structural analysis and the DFT calculation suggested that the considerable change of the rotational barriers by the electron effect of para-substituents is due to the disappearance of resonance stabilization energy caused by the twisting of para-substituted phenyl group in the transition state. This structural property of the N−C axially chiral anilines was employed to reveal a new acid-decelerated molecular rotor caused by the protonation at the remote position (remote proton brake).

KW - amines

KW - axial chirality

KW - density functional calculations

KW - electronic effect

KW - proton brake

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U2 - 10.1002/chem.201706115

DO - 10.1002/chem.201706115

M3 - Article

C2 - 29363203

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SN - 0947-6539

VL - 24

SP - 4453

EP - 4458

JO - Chemistry - A European Journal

JF - Chemistry - A European Journal

IS - 17

ER -

N−C Axially Chiral Anilines: Electronic Effect on Barrier to Rotation and A Remote Proton Brake

Abstract

Keywords

ASJC Scopus subject areas

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