Synthesis of a Conformationally Stable Atropisomeric Pair of Biphenyl Scaffold Containing Additional Stereogenic Centers

The synthesis of a new CF<sub>3</sub>-containing stereogenic atropisomeric pair of ortho-disubstituted biphenyl scaffold is presented. The atropisomers are surprisingly conformationally stable for isolation. X-ray structures show that their stability comes from an intramolecular hydrogen...

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Main Authors: Chi-Tung Yeung, Wesley Ting Kwok Chan, Wai-Sum Lo, Ga-Lai Law, Wing-Tak Wong
Format: Article
Language:English
Published: MDPI AG 2019-02-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/24/3/643
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spelling doaj-6b06fed66d4c40739987fe686e5cfd812020-11-25T02:46:23ZengMDPI AGMolecules1420-30492019-02-0124364310.3390/molecules24030643molecules24030643Synthesis of a Conformationally Stable Atropisomeric Pair of Biphenyl Scaffold Containing Additional Stereogenic CentersChi-Tung Yeung0Wesley Ting Kwok Chan1Wai-Sum Lo2Ga-Lai Law3Wing-Tak Wong4The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518000, PR ChinaState Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon 999077, Hong KongThe Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518000, PR ChinaThe Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518000, PR ChinaThe Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518000, PR ChinaThe synthesis of a new CF<sub>3</sub>-containing stereogenic atropisomeric pair of ortho-disubstituted biphenyl scaffold is presented. The atropisomers are surprisingly conformationally stable for isolation. X-ray structures show that their stability comes from an intramolecular hydrogen bond formation from their two hydroxyl groups and renders the spatial arrangement of their peripheral CF<sub>3</sub> and CH<sub>3</sub> groups very different. The synthesized stereogenic scaffold proved to be effective in catalyzing the asymmetric <i>N</i>-nitroso aldol reaction of enamine and nitrosobenzene. Compared to similar scaffolds without CF<sub>3</sub> groups, one of our atropisomer exhibits an increase in enantioselectivity in this reaction.https://www.mdpi.com/1420-3049/24/3/643atropisomerasymmetryhydrogen bond<i>N</i>-nitroso aldol reaction
collection DOAJ
language English
format Article
sources DOAJ
author Chi-Tung Yeung
Wesley Ting Kwok Chan
Wai-Sum Lo
Ga-Lai Law
Wing-Tak Wong
spellingShingle Chi-Tung Yeung
Wesley Ting Kwok Chan
Wai-Sum Lo
Ga-Lai Law
Wing-Tak Wong
Synthesis of a Conformationally Stable Atropisomeric Pair of Biphenyl Scaffold Containing Additional Stereogenic Centers
Molecules
atropisomer
asymmetry
hydrogen bond
<i>N</i>-nitroso aldol reaction
author_facet Chi-Tung Yeung
Wesley Ting Kwok Chan
Wai-Sum Lo
Ga-Lai Law
Wing-Tak Wong
author_sort Chi-Tung Yeung
title Synthesis of a Conformationally Stable Atropisomeric Pair of Biphenyl Scaffold Containing Additional Stereogenic Centers
title_short Synthesis of a Conformationally Stable Atropisomeric Pair of Biphenyl Scaffold Containing Additional Stereogenic Centers
title_full Synthesis of a Conformationally Stable Atropisomeric Pair of Biphenyl Scaffold Containing Additional Stereogenic Centers
title_fullStr Synthesis of a Conformationally Stable Atropisomeric Pair of Biphenyl Scaffold Containing Additional Stereogenic Centers
title_full_unstemmed Synthesis of a Conformationally Stable Atropisomeric Pair of Biphenyl Scaffold Containing Additional Stereogenic Centers
title_sort synthesis of a conformationally stable atropisomeric pair of biphenyl scaffold containing additional stereogenic centers
publisher MDPI AG
series Molecules
issn 1420-3049
publishDate 2019-02-01
description The synthesis of a new CF<sub>3</sub>-containing stereogenic atropisomeric pair of ortho-disubstituted biphenyl scaffold is presented. The atropisomers are surprisingly conformationally stable for isolation. X-ray structures show that their stability comes from an intramolecular hydrogen bond formation from their two hydroxyl groups and renders the spatial arrangement of their peripheral CF<sub>3</sub> and CH<sub>3</sub> groups very different. The synthesized stereogenic scaffold proved to be effective in catalyzing the asymmetric <i>N</i>-nitroso aldol reaction of enamine and nitrosobenzene. Compared to similar scaffolds without CF<sub>3</sub> groups, one of our atropisomer exhibits an increase in enantioselectivity in this reaction.
topic atropisomer
asymmetry
hydrogen bond
<i>N</i>-nitroso aldol reaction
url https://www.mdpi.com/1420-3049/24/3/643
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AT galailaw synthesisofaconformationallystableatropisomericpairofbiphenylscaffoldcontainingadditionalstereogeniccenters
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