CYCLOADDITION REACTIONS OF ORGANOIRON(II) CYCLOPENTADIENE COMPLEXES. NEW SELECTIVE STEREOSPECIFIC TRANSFORMATIONS OF ORGANOIRON(II) COMPLEXES.

Persistent Link:
http://hdl.handle.net/10150/187832
Title:
CYCLOADDITION REACTIONS OF ORGANOIRON(II) CYCLOPENTADIENE COMPLEXES. NEW SELECTIVE STEREOSPECIFIC TRANSFORMATIONS OF ORGANOIRON(II) COMPLEXES.
Author:
MCCONNELL, WESLEY WAYNE.
Issue Date:
1984
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The scope of the cycloaddition reaction between .eta.-5-cyclopentadienyliron(II) dicarbonyl-.eta.-1-cyclopentadiene (1.12a) and electrophilic olefins (1.4) and acetylenes (1.5) producing 7-syn-.eta.-5-cyclopentadienyliron(II) dicarbonyl-.eta.-1-bicyclo 2.2.1 hept-5-enes (2.1) and 7-syn-.eta.-5-cyclopentadienyliron(II) dicarbonyl-.eta.-1-bicyclo 2.2.1 hept-2,5-dienes (2.2), respectively, is found to be general for non-sterically hindered olefins and bis-activated acetylenes. The range of reactive 1.4 compounds is extended to include some sterically hindered olefins through precoordination of the olefin to diethylchloroalane or ethyldichloroalane. In contrast to all other acyclic cis and trans-1,2-disubstituted olefins, maleonitrile (1.41) cycloadds with 1.12a with complete retention of alkene stereochemistry. The relative rates for the cycloaddition between 1.12a and 1.41 in benzene, dichloromethane, and methanol are found to be 1:2:4, respectively. These stereochemical and kinetic results are more consistent with a concerted 4+2 cycloaddition than a two-step dipolar 3+2 cycloaddition. A dramatic stereochemical dependence on solvent polarity is observed in the cycloadducts resulting from the reaction of 1.12a with 1.41. Depending on the solvent the Alder "endo" rule is obeyed (methanol) or flagrantly violated (benzene). Reaction of 2.1 with ammonium cerium(IV) nitrate, bromine, or chlorine in acetonitrile containing excess sodium azide gives bicyclo 2.2.1 hept-5-ene-7-syn-carbonylazides (3.4). The reaction is found to be general using 1,2-disubstituted 2.1 compounds with bromine or chlorine. The thermally induced rearrangement of 3.4 compounds in refluxing toluene-tert-butanol gives 7-syn-t-Boc-aminobicyclo 2.2.1 hept-5-enes (4.4) in good yield. This is the first high yield stereospecific synthesis of 4.4 compounds. Furthermore, the synthetic equivalency of 1.12a is shown to include 5-carbonylazide-1,3-cyclopentadiene (3.9) and 5-t-boc-amino-1,3-cyclopentadiene (4.5) as well as 5-carbomethoxy-1,3-cyclopentadiene (3.10) 11.12 .
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Organoiron compounds.; Cyclopentadiene.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Glass, Richard S.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleCYCLOADDITION REACTIONS OF ORGANOIRON(II) CYCLOPENTADIENE COMPLEXES. NEW SELECTIVE STEREOSPECIFIC TRANSFORMATIONS OF ORGANOIRON(II) COMPLEXES.en_US
dc.creatorMCCONNELL, WESLEY WAYNE.en_US
dc.contributor.authorMCCONNELL, WESLEY WAYNE.en_US
dc.date.issued1984en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe scope of the cycloaddition reaction between .eta.-5-cyclopentadienyliron(II) dicarbonyl-.eta.-1-cyclopentadiene (1.12a) and electrophilic olefins (1.4) and acetylenes (1.5) producing 7-syn-.eta.-5-cyclopentadienyliron(II) dicarbonyl-.eta.-1-bicyclo 2.2.1 hept-5-enes (2.1) and 7-syn-.eta.-5-cyclopentadienyliron(II) dicarbonyl-.eta.-1-bicyclo 2.2.1 hept-2,5-dienes (2.2), respectively, is found to be general for non-sterically hindered olefins and bis-activated acetylenes. The range of reactive 1.4 compounds is extended to include some sterically hindered olefins through precoordination of the olefin to diethylchloroalane or ethyldichloroalane. In contrast to all other acyclic cis and trans-1,2-disubstituted olefins, maleonitrile (1.41) cycloadds with 1.12a with complete retention of alkene stereochemistry. The relative rates for the cycloaddition between 1.12a and 1.41 in benzene, dichloromethane, and methanol are found to be 1:2:4, respectively. These stereochemical and kinetic results are more consistent with a concerted 4+2 cycloaddition than a two-step dipolar 3+2 cycloaddition. A dramatic stereochemical dependence on solvent polarity is observed in the cycloadducts resulting from the reaction of 1.12a with 1.41. Depending on the solvent the Alder "endo" rule is obeyed (methanol) or flagrantly violated (benzene). Reaction of 2.1 with ammonium cerium(IV) nitrate, bromine, or chlorine in acetonitrile containing excess sodium azide gives bicyclo 2.2.1 hept-5-ene-7-syn-carbonylazides (3.4). The reaction is found to be general using 1,2-disubstituted 2.1 compounds with bromine or chlorine. The thermally induced rearrangement of 3.4 compounds in refluxing toluene-tert-butanol gives 7-syn-t-Boc-aminobicyclo 2.2.1 hept-5-enes (4.4) in good yield. This is the first high yield stereospecific synthesis of 4.4 compounds. Furthermore, the synthetic equivalency of 1.12a is shown to include 5-carbonylazide-1,3-cyclopentadiene (3.9) and 5-t-boc-amino-1,3-cyclopentadiene (4.5) as well as 5-carbomethoxy-1,3-cyclopentadiene (3.10) 11.12 .en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectOrganoiron compounds.en_US
dc.subjectCyclopentadiene.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorGlass, Richard S.en_US
dc.identifier.proquest8504124en_US
dc.identifier.oclc693399977en_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.