Control of Regioselectivity by the <i>l</i><i>one</i> Substituent through Steric and Electronic Effects in the Nitrosoarene Ene Reaction of Deuterium-Labeled Trisubstituted Alkenes
For the enereaction of 4-nitronitrosobenzene (ArNO) with a variety of primary and secondary lone alkyl-substituted substrates, the twix/twin regioselectivity is constant at about 85:15. In contrast, for the lone tert-butyl group and for lone aryl substituents, the twix regioisomer is obtained exclusively. These regioselectivities have been rationalized in terms of steric interactions and coordination
Ene Hydroperoxidation of Isobutenylarenes within Dye-Exchanged Zeolite Na−Y: Control of Site Selectivity by Cation−Arene Interactions
作者:Manolis Stratakis、Constantinos Rabalakos、Giannis Mpourmpakis、George E. Froudakis
DOI:10.1021/jo020599g
日期:2003.4.1
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 CF3-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.
GRDINA M. B.; ORFANOPOULOS M.; STEPHENSON L. M., J. ORG. CHEM., 1979, 44, NO 16, 2936-2938
作者:GRDINA M. B.、 ORFANOPOULOS M.、 STEPHENSON L. M.