Regioselective photoalkylation of 2-cyano-6-methoxynaphthalene by methoxy-substituted 1,2-diarylcyclopropanes

Photoreactions of 2-cyano-6-methoxynaphthalene with methoxy-substituted 1,2-diarylcyclopropanes in benzene give 2-cyano-1-(1,3-diarylpropyl)-6-methoxynaphthalenes. The excellent regioselectivity seen in these processes can be explained by initial formation of singlet exciplexes, in which the dipoles of each component are oriented in opposite directions.