Modular Assembly of Spirocarbocyclic Scaffolds through Pd0 -Catalyzed Intermolecular Dearomatizing [2+2+1] Annulation of Bromonaphthols with Aryl Iodides and Alkynes.

A novel palladium(0)-catalyzed dearomatizing [2+2+1] spiroannulation of 1-bromo-2-naphthols with aryl iodides and alkynes was developed for the rapid assembly of spiro[indene-1,1'-naphthalen]-2'-ones. This three-component cascade reaction was realized through consecutive Catellani-type C-H activation, unsymmetrical biaryl coupling, alkyne migratory insertion, and arene dearomatization. The potential utility of our method is illustrated by the one-step construction of the polycyclic skeletons of dalesconols A and B from alkyne-tethered aryl iodides and 1-bromo-2-naphthol.