Palladium-catalyzed and ligand-controlled divergent cycloadditions of vinylidenecyclopropane-diesters with para-quinone methides enabled by zwitterionic π-propargyl palladium species

A palladium-catalyzed and ligand-controlled divergent synthesis of spiro-cyclohexadienones from p -quinone methides and VDCP-diesters was realized via zwitterionic π-propargyl palladium species and the mechanism was clarified by DFT calculations.