The recent claim [l] that lrl cycloadducts (I) can be obtained by treating l, P- dibromodifluorocyolopropene or 1, 2-diohlorotetrafluorocyclobutene with g-substituted iminopyridazinium ylides prompts us to disclose preliminary results of an investigation of reactions between l-iminopyridinium ylide and potential dipolarophiles of [2, 3]. the fluorocarbon class (1)"= l: R= II, Ph; X= COMe; Y= Br(II) ZH n= 2: REH, Ph; XE COMe, ...