Control of the mode selectivity (ene reaction versus [2 + 2] cycloaddition) in the photooxygenation of ene carbamates: directing effect of an alkenylic nitrogen functionality.
The geometry of the double bond in oxazolidinone-substituted ene carbamates controls the mode selectivity (ene reaction versus [2+2] cycloaddition) of singlet oxygen through stereoelectronic effects, whereas the chiral auxiliary provides high diastereoselectivity through steric shielding.
Adam
Waldemar
W
Institut für Organische Chemie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany. adam@chemie.uni-wuerzburg.de
Bosio
Sara G
SG
Turro
Nicholas J
NJ