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rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2009-1-2
pubmed:abstractText
The regioselectivity of the [2 + 2] photocycloaddition reaction between triplet pi pi(*) acrolein and substituted olefins in their ground states was studied using the reaction force concept and reactivity indices from conceptual spin-polarized density functional theory. In the first part, the reaction path was determined for the attack of the acrolein alpha- and beta-carbon atoms on the alkenes, yielding biradical intermediates evolving to the head-to-tail (HT) and head-to-head (HH) regioisomers, respectively. The beta pathway was found to be the most favorable path from the thermodynamic and kinetic points of view, indicating that the formation of the HH cycloadduct should be preferred for reactions with both electron-rich and electron-poor alkenes if this first step determines the final regioselectivity. In the second part, the reactivity of the biradical intermediates was characterized through global and local spin-polarized response functions, together with the local hard-soft acid-base principle. The results indicate that the intermediate formed from the electron-rich alkenes evolves preferentially toward the HT regioisomer whereas electron-poor alkenes tend to form the HH isomer, in agreement with experiment and previous theoretical studies.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Jan
pubmed:issn
1520-5215
pubmed:author
pubmed:issnType
Electronic
pubmed:day
8
pubmed:volume
113
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
332-44
pubmed:year
2009
pubmed:articleTitle
Theoretical study of the regioselectivity of [2 + 2] photocycloaddition reactions of acrolein with olefins.
pubmed:affiliation
Eenheid Algemene Chemie, Faculteit Wetenschappen, Vrije Universiteit Brussel, Pleinlaan 2, Brussels, Belgium. pjaqueol@vub.ac.be
pubmed:publicationType
Journal Article