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Direct synthesis of gem‐difluorinated carbocyclic molecules represents a longstanding challenge in organic chemistry. Herein, a Rh‐catalyzed [3+2] cycloaddition reaction between readily available gem‐difluorinated cyclopropanes (gem‐DFCPs) and internal olefins has been developed, enabling the efficient synthesis of gem‐difluorinated cyclopentanes with good functional group compatibility, excellent regioselectivity and good diastereoselectivity. The resulting gem‐difluorinated products can undergo downstream transformations to access various mono‐fluorinated cyclopentenes and cyclopentanes. This reaction demonstrates the use of gem‐DFCPs as a type of "CF2" C3 synthon for cycloaddition under transition metal catalysis, which provides potential strategy for synthesizing other gem‐difluorinated carbocyclic molecules. [ABSTRACT FROM AUTHOR]

As a special class of cyclopropanes, gem -difluorinated cyclopropanes have many fascinating properties as a result of the gem -difluoro substitution; thus, their reactions have received much attention from the synthetic chemistry community. Recently, gem -difluorinated cyclopropanes have gradually emerged as a type of novel and unique fluorinated allylic synthon in cross-coupling reactions for the synthesis of monofluoroalkenes. Herein, we briefly summarize recent advances in transition-metal-catalyzed reactions of gem -difluorinated cyclopropanes. 1 Introduction 2 Palladium-Catalyzed Reactions with Linear Selectivity 3 Palladium-Catalyzed Reactions with Branched Selectivity 4 Other Metal-Catalyzed Reactions 5 Conclusions [ABSTRACT FROM AUTHOR]

Herein, we report a rhodium catalyzed directing‐group free regioselective C−H allylation of simple arenes. Readily available gem‐difluorinated cyclopropanes can be employed as highly reactive allyl surrogates via a sequence of C−C and C−F bond activation, providing allyl arene derivatives in good yields with high regioselectivity under mild conditions. The robust methodology enables facile late‐stage functionalization of complex bioactive molecules. The high efficiency of this reaction is also demonstrated by the high turnover number (TON, up to 1700) of the rhodium catalyst on gram‐scale experiments. Preliminary success on kinetic resolution of this transformation is achieved, providing a promising access to enantio‐enriched gem‐difluorinated cyclopropanes. [ABSTRACT FROM AUTHOR]