Synthesis of Diiodinated All-Carbon 3,3′-Diphenyl-1,1′-spirobiindene Derivatives via Cascade Enyne Cyclization and Electrophilic Aromatic Substitution

A synthetic method
for the construction of diiodinated all-carbon
spirobiindene derivatives has been developed from the reaction of
propargyl alcohol-tethered alkylidenecyclopropanes with iodine. The
reaction proceeded through an iodination-initiated cascade intramolecular
enyne cyclization and electrophilic aromatic substitution reaction
process in 1,2-dichloroethane upon heating, giving desired spirocyclic
products in moderate to excellent yields. Further transformation of
the obtained products has also been presented.