Photosubstitution of 1-Methoxy-4-nitronaphthalene with Amine Nucleophiles: Dual Pathways

Article abstract of DOI:10.1021/jo00228a012

The photosubstitution of 1-methoxy-4-nitronaphthalene (MNN) with amines has been investigated by a combination of continuous and time-resolved experiments.Primary amines cause replacement of the nitro group, while secondary amines displace the methoxy substituent.Both reactions involve attack of the amine upon the triplet excited state of MNN.Spectroscopic evidence for the radical anion MNN^*- has been obtained; the yield of this species depends upon the structure of the amine in the order RNH2*-, but that the reaction with primary amines is most probably an example of an S_N2 Ar^* process.The results for MNN and related compounds are discussed in the context of the orientation rules proposed by Mutai et al.