The value of 2 J P–CO as a diagnostic parameter for the structure and thermal reactivity of carbonyl-stabilised phosphonium ylides

2.50
Hdl Handle:
http://hdl.handle.net/2436/620819
Title:
The value of 2 J P–CO as a diagnostic parameter for the structure and thermal reactivity of carbonyl-stabilised phosphonium ylides
Authors:
Aitken, R. Alan; Boubalouta, Youcef; Chang, Da; Cleghorn, Lee P.; Gray, Ian P.; Karodia, Nazira; Reid, Euan J.; Slawin, Alexandra M.Z.
Abstract:
A survey of 20 carbonyl-stabilised phosphonium ylides with recently reported X-ray structures shows a strong correlation between the CP to CO torsion angle and the value of 2JP–CO, with high values being associated with an anti configuration and low with syn. Seven new X-ray structural determinations are reported, several for types of ylide not crystallographically characterised before, and these also conform to this pattern. The value of 2JP–CO is then correlated with whether or not thermal extrusion of Ph3PO occurs to give alkynes for over 200 ylides and an empirical rule developed that the extrusion never occurs for ylides where this value is > 11 Hz. This is used to rationalise the anomalous behaviour of some trioxo ylides and cyclic ylides, two of which afford cycloalkynes, isolated after rearrangement as the isomeric 1,3-dienes. The rule also holds for a family of novel highly fluorinated ylides which afford fluorinated alkynes in good yield upon flash vacuum pyrolysis.
Citation:
The value of 2 J P–CO as a diagnostic parameter for the structure and thermal reactivity of carbonyl-stabilised phosphonium ylides 2017, 73 (44):6275 Tetrahedron
Publisher:
Elsevier
Journal:
Tetrahedron, Volume 73, Issue 44, 2 November 2017, Pages 6275-6285
Issue Date:
Nov-2017
URI:
http://hdl.handle.net/2436/620819
DOI:
10.1016/j.tet.2017.09.016
Additional Links:
http://linkinghub.elsevier.com/retrieve/pii/S0040402017309389
Type:
Article
Language:
en
ISSN:
0040-4020
Sponsors:
EPSRC (U.K.) for a DTA Studentship (Grant No. EP/P505712/1)
Appears in Collections:
FSE

Full metadata record

DC FieldValue Language
dc.contributor.authorAitken, R. Alanen
dc.contributor.authorBoubalouta, Youcefen
dc.contributor.authorChang, Daen
dc.contributor.authorCleghorn, Lee P.en
dc.contributor.authorGray, Ian P.en
dc.contributor.authorKarodia, Naziraen
dc.contributor.authorReid, Euan J.en
dc.contributor.authorSlawin, Alexandra M.Z.en
dc.date.accessioned2017-11-01T14:25:48Z-
dc.date.available2017-11-01T14:25:48Z-
dc.date.issued2017-11-
dc.identifier.citationThe value of 2 J P–CO as a diagnostic parameter for the structure and thermal reactivity of carbonyl-stabilised phosphonium ylides 2017, 73 (44):6275 Tetrahedronen
dc.identifier.issn0040-4020en
dc.identifier.doi10.1016/j.tet.2017.09.016-
dc.identifier.urihttp://hdl.handle.net/2436/620819-
dc.description.abstractA survey of 20 carbonyl-stabilised phosphonium ylides with recently reported X-ray structures shows a strong correlation between the CP to CO torsion angle and the value of 2JP–CO, with high values being associated with an anti configuration and low with syn. Seven new X-ray structural determinations are reported, several for types of ylide not crystallographically characterised before, and these also conform to this pattern. The value of 2JP–CO is then correlated with whether or not thermal extrusion of Ph3PO occurs to give alkynes for over 200 ylides and an empirical rule developed that the extrusion never occurs for ylides where this value is > 11 Hz. This is used to rationalise the anomalous behaviour of some trioxo ylides and cyclic ylides, two of which afford cycloalkynes, isolated after rearrangement as the isomeric 1,3-dienes. The rule also holds for a family of novel highly fluorinated ylides which afford fluorinated alkynes in good yield upon flash vacuum pyrolysis.en
dc.description.sponsorshipEPSRC (U.K.) for a DTA Studentship (Grant No. EP/P505712/1)en
dc.language.isoenen
dc.publisherElsevieren
dc.relation.urlhttp://linkinghub.elsevier.com/retrieve/pii/S0040402017309389en
dc.rightsArchived with thanks to Tetrahedronen
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/*
dc.subjectYlidesen
dc.subjectX-ray structureen
dc.subjectNMR coupling constantsen
dc.subjectPyrolysisen
dc.subjectCycloalkynesen
dc.titleThe value of 2 J P–CO as a diagnostic parameter for the structure and thermal reactivity of carbonyl-stabilised phosphonium ylidesen
dc.typeArticleen
dc.identifier.journalTetrahedron, Volume 73, Issue 44, 2 November 2017, Pages 6275-6285en
dc.date.accepted2017-09-
rioxxterms.funderEPSRC (U.K.) for a DTA Studentship (Grant No. EP/P505712/1)en
rioxxterms.identifier.projectUoW011117NKen
rioxxterms.versionAMen
rioxxterms.licenseref.urihttps://creativecommons.org/CC BY-NC-ND 4.0en
rioxxterms.licenseref.startdate2018-11-02en
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