Hydrocarbon Functionalization via a New Free Radical-Based Condensation Reaction

A new free radical chain process for the allylation of hydrocarbons and some other substrates utilizing substituted allyl bromides (R-H + C=C-C-Br -> R-C-C=C + HBr) has been developed. Good to excellent yields were observed in all cases. Kinetic chain measurements and competition experiments were performed in order to elucidate the mechanism of the reaction. Overall, the results are consistent with a free radical chain process with bromine atom as the chain carrier. Substitution effects on the reactivity of the allyl bromides (CH2=C(Z)CH2Br) and their influence on the overall reaction rate were studied by conducting several competition experiments. The relative rate constants for addition of benzyl radical to CH2=C(Z)CH2Br are: Z=CN(180), COOEt(110), Ph(65), H(1.0). The trend of electronegativity/reactivity of these reactions was very similar to that reported for addition of benzyl radical to substituted alkenes. Other than alkyl aromatics (PhCH3, PhCH(CH3)2), other substrates (i.e., 2- propanol, phenyl cyclopropane) were also tested for this allylation reaction. The magnitude and scope of these reactions, and their synthetic utility is discussed.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Chemistry

Department dc:contributor.department

Chemistry

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1998

Author dc:creator

• Sadeghipour, Mitra

Chair dc:contributor.committeechair

• Tanko, James M.

Committee members dc:contributor.committeemember

• Bell, Harold M.
• Castagnoli, Neal Jr.
• Kingston, David G. I.
• Brewer, Karen J.
• Tanko, James M.

• Addition
• Allylation
• Allyl bromide
• Alkyl aromatic
• Bromine
• Condensation
• Fragmentation
• Free Radical
• Hydrocarbon
• 2-Propanol
• Reaction Mechanism
• Synthesis

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-61598-21627

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/30627