Ene hydroperoxidation of isobutenylarenes within dye-exchanged zeolite Na-Y: control of site selectivity by cation-arene interactions.
The site selectivity in the singlet oxygen ene reaction of several deuterium-labeled isobutenylarenes depends on the position and the electronic nature of the aryl substitutents. For example, 1-(4-trifluoromethylphenyl)-2-methylpropene gives 82% twin selectivity whereas the isomeric 1-(2-trifluoromethylphenyl)-2-methylpropene gives 68% twix selectivity. If photooxygenation of these CF(3)-substituted compounds is carried out in solution, the opposite selectivity trends are found. On the basis of DFT calculations, these results are rationalized in terms of oxygen-cation and cation-arene interactions.
Stratakis
Manolis
M
Department of Chemistry, University of Crete, 71409 Iraklion, Greece. stratakis@chemistry.uoc.gr
Rabalakos
Constantinos
C
Mpourmpakis
Giannis
G
Froudakis
George E
GE