A facile method for the synthesis of a new class of disubstituted
alkylidenecyclopentenes has been introduced. The methodology involves
the palladium-catalyzed ring opening of pentafulvene-derived bicyclic
hydrazines with phenols and active methylene compounds, furnishing
1,4-disubstituted alkylidenecyclopentenes in good yield. The utility
of multiple points of functionalization was effectively demonstrated
by the synthesis of a substituted cyclopentanone and 2-hydrazinofulvene.
azabicyclic olefin - palladium - soft nucleophile - alkylidenecyclopentene - substituted cyclopentanone - 2-hydrazinofulvene