Atropisomerisation in sterically hindered alpha,beta-disubstituted cyclopentenones derived from an intermolecular cobalt(0)-mediated Pauson-Khand reaction

Benjamin E. Moulton; Jason M. Lynam; Anne-Kathrin Duhme-Klair; Wenxu Zheng; Zhenyang Lin; Ian J. S. Fairlamb

doi:10.1039/c0ob00264j

Atropisomerisation in sterically hindered alpha,beta-disubstituted cyclopentenones derived from an intermolecular cobalt(0)-mediated Pauson-Khand reaction

Benjamin E. Moulton, Jason M. Lynam, Anne-Kathrin Duhme-Klair, Wenxu Zheng, Zhenyang Lin, Ian J. S. Fairlamb

Chemistry

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

Abstract

4-(2-Phenylethynyl)-2H-chromen-2-one reacts with norbornene and Co-2(CO)(8) in an intermolecular Pauson-Khand reaction by focused microwave dielectric heating. Two regioisomeric products are formed; the electron-deficient coumarin moiety preferentially occupies the beta-position of the cyclopentenone ring system, whereas the phenyl occupies the a-position. The sterically hindered alpha,beta-(2,3)-disubstituted cyclopentenone regioisomeric products exhibit pronounced atropisomerisation, and the magnitude of the energetic barrier to interconversion between these atropisomers is dependent on the relative position of the coumarin moieties. Interconversion is slow when the coumarin is found in the a-position, whereas interconversion is relatively fast when found in the b-position.

Original language	English
Pages (from-to)	5398-5403
Number of pages	6
Journal	Organic and Biomolecular Chemistry
Volume	8
Issue number	23
DOIs	https://doi.org/10.1039/c0ob00264j
Publication status	Published - 7 Dec 2010

Keywords

RAY CRYSTAL-STRUCTURE
COMPLEXES
DENSITY
REGIOSELECTIVITY
REGIOCHEMISTRY
ALKYNES
INTERMEDIATE
POLARIZATION
MECHANISM
LIGANDS

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10.1039/c0ob00264j

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title = "Atropisomerisation in sterically hindered alpha,beta-disubstituted cyclopentenones derived from an intermolecular cobalt(0)-mediated Pauson-Khand reaction",

abstract = "4-(2-Phenylethynyl)-2H-chromen-2-one reacts with norbornene and Co-2(CO)(8) in an intermolecular Pauson-Khand reaction by focused microwave dielectric heating. Two regioisomeric products are formed; the electron-deficient coumarin moiety preferentially occupies the beta-position of the cyclopentenone ring system, whereas the phenyl occupies the a-position. The sterically hindered alpha,beta-(2,3)-disubstituted cyclopentenone regioisomeric products exhibit pronounced atropisomerisation, and the magnitude of the energetic barrier to interconversion between these atropisomers is dependent on the relative position of the coumarin moieties. Interconversion is slow when the coumarin is found in the a-position, whereas interconversion is relatively fast when found in the b-position.",

keywords = "RAY CRYSTAL-STRUCTURE, COMPLEXES, DENSITY, REGIOSELECTIVITY, REGIOCHEMISTRY, ALKYNES, INTERMEDIATE, POLARIZATION, MECHANISM, LIGANDS",

author = "Moulton, {Benjamin E.} and Lynam, {Jason M.} and Anne-Kathrin Duhme-Klair and Wenxu Zheng and Zhenyang Lin and Fairlamb, {Ian J. S.}",

year = "2010",

month = dec,

day = "7",

doi = "10.1039/c0ob00264j",

language = "English",

volume = "8",

pages = "5398--5403",

journal = "Organic and Biomolecular Chemistry",

issn = "1477-0520",

publisher = "The Royal Society of Chemistry",

number = "23",

}

Atropisomerisation in sterically hindered alpha,beta-disubstituted cyclopentenones derived from an intermolecular cobalt(0)-mediated Pauson-Khand reaction. / Moulton, Benjamin E.; Lynam, Jason M.; Duhme-Klair, Anne-Kathrin et al.
In: Organic and Biomolecular Chemistry, Vol. 8, No. 23, 07.12.2010, p. 5398-5403.

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

TY - JOUR

T1 - Atropisomerisation in sterically hindered alpha,beta-disubstituted cyclopentenones derived from an intermolecular cobalt(0)-mediated Pauson-Khand reaction

AU - Moulton, Benjamin E.

AU - Lynam, Jason M.

AU - Duhme-Klair, Anne-Kathrin

AU - Zheng, Wenxu

AU - Lin, Zhenyang

AU - Fairlamb, Ian J. S.

PY - 2010/12/7

Y1 - 2010/12/7

N2 - 4-(2-Phenylethynyl)-2H-chromen-2-one reacts with norbornene and Co-2(CO)(8) in an intermolecular Pauson-Khand reaction by focused microwave dielectric heating. Two regioisomeric products are formed; the electron-deficient coumarin moiety preferentially occupies the beta-position of the cyclopentenone ring system, whereas the phenyl occupies the a-position. The sterically hindered alpha,beta-(2,3)-disubstituted cyclopentenone regioisomeric products exhibit pronounced atropisomerisation, and the magnitude of the energetic barrier to interconversion between these atropisomers is dependent on the relative position of the coumarin moieties. Interconversion is slow when the coumarin is found in the a-position, whereas interconversion is relatively fast when found in the b-position.

AB - 4-(2-Phenylethynyl)-2H-chromen-2-one reacts with norbornene and Co-2(CO)(8) in an intermolecular Pauson-Khand reaction by focused microwave dielectric heating. Two regioisomeric products are formed; the electron-deficient coumarin moiety preferentially occupies the beta-position of the cyclopentenone ring system, whereas the phenyl occupies the a-position. The sterically hindered alpha,beta-(2,3)-disubstituted cyclopentenone regioisomeric products exhibit pronounced atropisomerisation, and the magnitude of the energetic barrier to interconversion between these atropisomers is dependent on the relative position of the coumarin moieties. Interconversion is slow when the coumarin is found in the a-position, whereas interconversion is relatively fast when found in the b-position.

KW - RAY CRYSTAL-STRUCTURE

KW - COMPLEXES

KW - DENSITY

KW - REGIOSELECTIVITY

KW - REGIOCHEMISTRY

KW - ALKYNES

KW - INTERMEDIATE

KW - POLARIZATION

KW - MECHANISM

KW - LIGANDS

UR - http://www.scopus.com/inward/record.url?scp=78149436129&partnerID=8YFLogxK

U2 - 10.1039/c0ob00264j

DO - 10.1039/c0ob00264j

M3 - Article

SN - 1477-0520

VL - 8

SP - 5398

EP - 5403

JO - Organic and Biomolecular Chemistry

JF - Organic and Biomolecular Chemistry

IS - 23

ER -

Atropisomerisation in sterically hindered alpha,beta-disubstituted cyclopentenones derived from an intermolecular cobalt(0)-mediated Pauson-Khand reaction

Abstract

Keywords

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