Cover Picture: In Situ Generation of Difluoromethyl Diazomethane for [3+2] Cycloadditions with Alkynes (Angew. Chem. Int. Ed. 22/2015)

The elusive reagent difluoromethyl diazomethane (CF₂HCHN₂) was generated in situ for the first time and employed in [3+2] cycloaddition reactions with alkynes. In his Communication on page 6558 ff., P. Mykhailiuk describes that this one-pot process for the synthesis of difluoromethylated pyrazoles is very practical as it does not require a catalyst or the isolation of the potentially toxic and explosive gaseous intermediate and can be easily scaled up.