Corey-Chaykovsky Cyclopropanation of Nitronaphthalenes: Access to Benzonorcaradienes and Related Systems.

Nitronaphthalene derivatives react as Michael acceptors in the Corey-Chaykovsky reaction with alkyl phenyl selenones and alkyl diphenyl sulfonium salts. Mechanistic studies reveal that sterically demanding substituents at the carbanionic center favor formation of cyclopropanes and suppress competitive β-elimination to the alkylated products. The transformation, demonstrated also on heterocyclic nitroquinoline and nitroindazolines, is an example of transition metal-free dearomatization method.