Generation of acyloxyketenes from unstable mesoionic 1,3-dioxolium-4-olates and their reaction with ketenophiles to give [2 + 2] cycloadducts
Fast ring opening of mesoionic 1,3-dioxolium-4-olates, generated by Rh 2(OAc)4-catalyzed decomposition of phenyldiazoacetic anhydride derivatives, to acyloxyphenylketenes was demonstrated by trapping the ketenes with several ketenoph