Dearomatization of Naphthalene:  Stereoselective cis-1,4 Tandem Additions Promoted by Osmium(II)

The naphthalene complex of pentaammineosmium(II) (1) reacts with four different classes of electrophiles to form 1-naphthalenium species 2−5. These η³-allyl complexes react stereospecifically with a variety of nucleophiles to form cis-1,4-dihydronaphthalene complexes. The entire reaction sequence may be performed outside a glovebox in two steps using conventional techniques.