Recent Progress in the Application of Difluoromethyl Diazomethane as Fluorine-Containing Building Block

Difluoromethylation has achieved remarkable progress in the past two decades.In addition to the direct difluoromethylation and the stepwise difluoromethylation, chemical transformation starting from CF2H-containing building blocks is a novel strategy to introduce difluoromethyl group into organic compounds.Compared with electrophilic-, nucleophilic-and free radical-difluoromethylation reagents, the types of CF2H-containing building blocks are still limited and less explored.Among them, difluoromethyl diazomethane (CF2HCHN2) is a new type of fluorine-containing building block developed in recent years, which has received much attention from researchers.The recent progress in the application of difluoromethyl diazomethane and its surrogates as fluorine-containing building blocks is summarized, focusing on the reaction types and related mechanisms, and the developmental direction in the future is prospected.