On the addition of 4-(N,N-dimethylamino)phenyl cation to norbornene

Abstract

The photochemically generated 4-(N,N-dimethylamino)phenyl cation adds to norbornene giving a phenylnortricyclene and various 2-exo substituted phenylnorbornanes (main isomers, 3-endo-, 7-anti- and 7-syn-phenyl). Acetamides are obtained in MeCN and ethers in alcohols (MeOH, iso-PrOH, tert-BuOH, CF₃CH₂OH). The product distribution is closely reminiscent of that obtained in the solvolysis of 2-norbornyl derivatives, supporting that the reaction offers a novel access to a ‘non classical’ 2-norbornyl cation. The fate of this cation is determined by the basicity/nucleophilicity of the solvent.