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We report a general and efficient approach to construct achiral and chiral gem-difluoroallylic amines from a masked difluorodiazo reagent (PhSO2CF2CHN2) and readily available imines. This facile protocol takes advantage of the phenylsulfonyl and diazo moieties as efficient activating and directing groups to assist difluoroalkyl incorporation and facilitate the chemodivergent and stereoselective formation of gem-difluoroallylic amines.

A silver-catalyzed regioselective [3 + 2] cycloaddition reaction of PhSO2CF2CHN2with aryl diazonium salts is described. This protocol enables the straightforward construction of a novel class of difluoromethylated tetrazoles under mild conditions, tolerates a broad spectrum of functionalities, and is applicable to one-pot operation from commercially available aniline derivatives. The synthetic merit of this method is further demonstrated by the facile preparation of versatile difluoromethylated azoles, including a valuable HCF2-analogue of P2X3 receptor antagonist.

Phenylsulfone difluorodiazoethane (PhSO2CF2CHN2), an easy-to-prepare and bench-stable masked CF2-building block, has been developed. The synthetic utility of this reagent is demonstrated by a direct regioselective [3 + 2] cycloaddition with electron-deficient alkynes and alkenes. This protocol enables facile construction of an array of difluoromethyl-substituted pyrazoles in good to high yields under mild reaction conditions.

A base-mediated (3 + 2) cycloaddition of trifluoroacetohydrazonoyl chlorides with imidates for the construction of 3-trifluoromethyl-1,2,4-triazoles has been described. This reaction is characterized by readily starting materials, simple reaction conditions, good yields, a broad substrate scope, and excellent regioselectivity. The utility of this protocol has been validated by the synthesis of a drug-like molecule.