Fluorinated diazoalkanes – a versatile class of reagents for the synthesis of fluorinated compounds
Although diazoalkanes find regular application in organic synthesis, the synthesis and application of their fluorinated homologues was long neglected. First described in 1943, trifluorodiazoethane found its way into the organic synthesis repertoire only in the past decade for atom-economical and practical synthesis of fluorinated building blocks and currently emerges as a versatile reagent. The synthetic applicability of this reagent is currently being investigated in great detail and many interesting new reactivities, and procedures for the synthesis of fluoroalkyl-substituted building blocks have been developed. In this context, a range of new fluoroalkyl substituted diazoalkanes have been introduced in the past few years, ranging from perfluorinated diazoalkanes towards highly reactive difluorodiazoethane which was first described in 2015. This tutorial review covers historic milestones of fluoroalkyl substituted diazoalkanes and highlights recent examples which underscore their vast potential to the synthesis of fluorinated compounds.