Three-Component Coupling of Triflyloxy-Substituted Benzocyclobutenones, Organolithium Reagents, and Arynophiles Promoted by Generation of Aryne via Carbon-Carbon Bond Cleavage.

Treatment of benzocyclobutenones bearing a triflyloxy group adjacent to the four-membered ring with organolithium reagents in the presence of arynophiles efficiently affords three-component coupled α-arylketones. Mechanistic studies indicate that the reaction is promoted by generation of the aryne via carbon-carbon bond cleavage of a benzocyclobutenoxide intermediate, which led us to find a fluoride-mediated aryne generation method from triflyloxy-substituted benzocyclobutenone silyl acetal precursors.