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Building molecular complexity from simple feedstocks through peripheral and skeletal editing is central to modern organic synthesis. Nevertheless, a controllable strategy that can modify both the core skeleton and periphery of an aromatic heterocycle with a common substrate remains undeveloped, despite its potential to maximize structural diversity and applications. Here we report a fluoroalkyl carbene-initiated chemodivergent molecular editing of indoles, allowing both skeletal and peripheral editing by trapping electrophilic fluoroalkyl carbene generated in situ from fluoroalkyl N-triftosylhydrazones. A variety of fluorine-containing N-heterocyclic scaffolds could be efficiently achieved through the tunable chemoselective editing reactions at skeleton or periphery of the indole, including one-carbon insertion, C3−H gem-difluoroolefination, tandem cyclopropanation/N1−H gem-difluoroolefination, and cyclopropanation. Mechanistic experiments and computations have probed the reaction mechanism and the origins of chemo- and regioselectivity.

The first example of dearomative [4 + 3] cycloaddition between furans and vinyl-N-sulfonylhydrazones as vinylcarbene precursors is reported. The merger of silver catalysis and easily decomposable vinyl-N-triftosylhydrazones enabled the efficient synthesis of a variety of skeletally and functionally diverse oxa-bridged seven-membered bicyclic compounds with complete and predictable stereoselectivity. The combination of experimental studies and DFT calculations disclosed that the silver-catalyzed reaction proceeds via a concerted [4 + 3] cycloaddition mechanism, rather than the generally accepted cyclopropanation / Cope rearrangement pathway by rhodium catalysis.

The conversion of inexpensive aqueous ammonia (NH

Here we report the sulfinylsulfonation of alkynes to afford β-sulfinyl alkenylsulfone products with a broad substrate scope, excellent functional group compatibility, and high yield. Moreover, the sulfinylsulfonation reaction of enyne can also be realized for constructing functionalized carbo- and heterocycles through a radical cascade cyclization process.

To explore the mechanism of silver and rhodium catalysis and reveal the origin of the chemo- and enantioselectivity of the reaction, density functional theory calculations were performed on the first silver-catalyzed highly enantioselective carbene transfer reaction. The calculation results reveal that when silver is used as a catalyst, due to the participation of the phosphate anion in the transition state, the enhanced nucleophilicity of the α-diazoacetamide unit promotes smooth dearomatization before generation of the silver carbene. Because the generated rhodium carbene has stronger electrophilicity, typical carbene reactions (C-H insertion and the Büchner reaction) are favored. In addition, in the process of silver catalyzed dearomatization, the formation of an R-type transition state is determined by the small torsion energy and strong interaction energy.

Here we report a silver-catalyzed alkynyl carbene insertion into β-ketocarbonyls using alkynyl

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. The insertion of carbenes into the alpha-C-H bonds of ethers represents one of the most powerful approaches to access polysubstituted alpha-branched ethers. However, intermolecular carbene insertions remain challenging, since current approaches are generally limited to the use of toxic and potentially explosive alpha-diazocarbonyl compounds. We now report a silver-catalyzed alpha-C-H benzylation of ethers using bench-stable N-triftosylhydrazones as safe and convenient carbene precursors. This approach is well suited for both inter- and intramolecular insertions to deliver medicinally relevant homobenzylic ethers and 5-8-membered oxacycles in good yields. The synthetic utility of this strategy is demonstrated by its easy scalability, broad scope with valuable functional groups, high regioselectivity, and late-stage functionalization of complex oxygen-containing molecules. The relative reactivities of different types of silver carbenes and C-H bonds were also investigated by experments and DFT calculations.

Hydrodefluorination is one of the most promising chemical strategies to degrade perfluorochemicals into partially fluorinated compounds. However, controlled progressive hydrodefluorination remains a significant challenge, owing to the decrease in the strength of C-F bonds along with the defluorination. Here we describe a carbene strategy for the sequential (deutero)hydrodefluorination of perfluoroalkyl ketones under rhodium catalysis, allowing for the controllable preparation of difluoroalkyl- and monofluoroalkyl ketones from aryl- and even alkyl-substituted perfluoro-alkyl ketones in high yield with excellent functional group tolerance. The reaction mechanism and the origin of the intriguing chemoselectivity of the reaction were rationalized by density functional theory (DFT) calculations.

The insertion of carbenes into the α-C-H bonds of ethers represents one of the most powerful approaches to access polysubstituted α-branched ethers. However, intermolecular carbene insertions remain challenging, since current approaches are generally limited to the use of toxic and potentially explosive α-diazocarbonyl compounds. We now report a silver-catalyzed α-C-H benzylation of ethers using bench-stable N-triftosylhydrazones as safe and convenient carbene precursors. This approach is well suited for both inter- and intramolecular insertions to deliver medicinally relevant homobenzylic ethers and 5-8-membered oxacycles in good yields. The synthetic utility of this strategy is demonstrated by its easy scalability, broad scope with valuable functional groups, high regioselectivity, and late-stage functionalization of complex oxygen-containing molecules. The relative reactivities of different types of silver carbenes and C-H bonds were also investigated by experments and DFT calculations.

Correction for ‘Theoretical study on the mechanism, chemo- and enantioselectivity of the Ag- vs. Rh-catalyzed intramolecular carbene transfer reaction of diazoacetamides' by Qingmin Song et al., RSC Adv., 2022, 12, 18197–18208, https://doi.org/10.1039/D2RA01298G.