Search

Thermal [2+2] cycloaddition reactions are symmetry-forbidden due to ground-state orbital symmetry constraints, making them challenging to achieve under non-photochemical conditions. Now a stepwise radical intramolecular thermal crossed [2+2] cycloaddition of N-(homo)allyl gem-difluoroenamines and homoallyl gem-difluorovinyl ethers has been accomplished, through tandem gem-difluoroalkenylation of N-(homo)allylamines and homoallyl alcohols with trifluoromethyl triftosylhydrazones.

A state-of-the-art tool in synthetic organic chemistry is a rhodium diazocarbene species, which despite its flexibility, is derived from expensive and highly reactive species. Here the authors present a methodology for C–H benzylation of ethers via an analogous silver carbene species, obtained from a more common metal and a more stable starting material.

Ciamician–Dennstedt rearrangement remains limited to halocarbene precursors. Herein, the authors report a general methodology for the Ciamician-Dennstedt reaction using α-halogen-free carbenes generated in situ from N-triftosylhydrazones.

Skeletal editing has emerged as an appealing strategy for scaffold-hopping-based drug discovery, but the enantioselective single-atom skeletal editing of N-heteroarenes is challenging. Now, using trifluoromethyl N-triftosylhydrazones as carbene precursors, the enantiodivergent dearomative skeletal editing of indoles and pyrroles has been achieved through asymmetric carbon-atom insertion.

Epoxides are prominent small-ring O-heterocycles found in a variety of bioactive natural products and pharmaceuticals. Here, the authors report a silver carbene strategy to achieve O-to-C atom exchange of epoxides in a single step, affording diverse fluoroalkylcyclopropanes.

The rapid generation of molecular complexity from a given molecular scaffold is crucial to drug discovery and development. Now the chemodivergent molecular editing of indoles using fluoroalkyl carbenes has been developed to modularly access four different types of fluorine-containing N-heterocyclic compound with high molecular complexity.

The selective functionalization of trifluoromethyl groups is challenging due to the inertness of the C–F bonds. Here the authors report a method for the carbodefluorination of C–F bonds of fluoroalkyl ketones via a carbene-initiated rearrangement strategy.

Sulfinyl radicals are an underexplored synthon in organic chemistry due to the fact that they reversibly add to pi systems and undergo homodimerization. Here the authors synthesize sulfonyl sulfones, previously thought to be unstable, and demonstrate their broad use as sulfinyl radical precursors in disulfurizations of alkenes and alkynes.