(3 + 2) cycloaddition of 2-alkoxynaphthalenes with azaoxyallyl cations: access to benzo[e]indolones

A route to functionalized benzo[ e ]indolones has been reported via (3 + 2) cycloaddition of in situ generated azaoxyallyl cations with alkoxynaphthalene followed by aryl C–O bond cleavage. The intermediate adduct has been isolated and characterized.