We disclose a novel Pd-catalyzed assembly of fluoren-9-ones by merging of C–H activation and difluorocarbene transfer. ClCF2COONa served as a difluorocarbene precursor to be harnessed as a carbonyl source in this transformation. The current protocol enables us to afford fluoren-9-ones in high yields with excellent functional group compatibility, which also represents the first example of using difluorocarbene as a coupling partner in transition-metal-catalyzed C–H activation.

We report herein an efficient strategy to construct 3-(2,2-difluoroethyl)-2-fluoroindoles from activated o-aminostyrenes with ethyl bromodi-fluoroacetate as a difluorocarbene source. Through double capture of a difluorocarbene, two different types of fluorine motifs are incorporated into the products with simultaneous construction of one C−N and two C−C bonds, without the need for transition metals. This reaction features high efficiency and excellent functional group compatibility and has great potential in the late-stage modifications of pharmaceutical molecules and natural products.

An unprecedented difluorocarbene-mediated C-O bond cleavage of cyclic ethers for the construction of difluoromethyl ethers is disclosed. This protocol is distinguished by its mild conditions, high efficiency and wide substrate scope, which could tolerate both sensitive functional groups such as hydroxyl group, olefin and C-C triple bonds as well as complex molecules, thus demonstrates excellent chemoselectivities and has great potential in the late-stage modifications of pharmaceutical compounds and natural products. It is worth noting that this method can not only introduce fluorine atoms into the final molecules, but also can be effectively formed an ester-and an ether linkage.

A simple and efficient construction of 2-difluoro-2,3-dihydrofurans was reported, which features metal-free, additive-free, broad functional group tolerance and readily accessible starting materials. It is worth mentioning that this type of...

A convenient and efficient palladium-catalyzed C–H bond activation for the assembly of N-aryl carbazole is reported, in which two C–N bonds were formed under one set of conditions.