A Hexavalent Tellurium-Based Chalcogen Bonding Catalysis Platform: High Catalytic Activity and Controlling of Selectivity

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Янв. 13, 2025

Herein, we describe a hexavalent tellurium-based chalcogen bonding catalysis platform capable of addressing reactivity and selectivity issues. This research demonstrates that tellurium salts can serve as class highly active catalysts for the first time. The centers in these have only one exposed interaction site, thus providing favorable condition controlling reaction selectivity. advantages were demonstrated by their remarkable catalytic activity cyanidation difluorocyclopropenes through C-F bond activation, which otherwise low reactive under strong Lewis acids or inaccessible representative divalent/tetravalent donors. catalyst was further highlighted its capability to address previously unresolved problem associated with acid approach, upon using some less silyl enol ethers nucleophiles functionalization difluorocyclopropenes. generality this versatile application different systems. differentiate two similar free OH groups glycosyl acceptors achieve excellent regio- stereoselectivity synthesis disaccharides, tetravalent gave Mechanistic investigation suggests catalyst-glycosyl donor-acceptor ternary supramolecular complex is operative.

Язык: Английский

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Rh(II) and Chiral Phosphoric Acid Co-catalyzed Selective O–H Insertions for Stereodivergent O-Alkylation of Glycosides

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Фев. 10, 2025

Carbohydrates are synthetically challenging molecules with essential biological functions in all living systems. The selective synthesis and modification of carbohydrates crucial for investigating their functions. Controlling chemo-, regio-, stereoselectivity is a central theme carbohydrate synthesis. Achieving the full set stereoisomers derivatives would significantly enhance efficiency building compound libraries studies drug discovery. However, functionalization seemingly identical hydroxyl groups remains long-standing challenge organic chemistry. In synthesis, achieving precise control both relative configurations catalyst-controlled reactions that create new stereocenter presents significant synthetic challenge. Herein, we developed an efficient method stereodivergent O-alkylation via Rh(II)/chiral phosphoric acid-cocatalyzed insertion metal carbenoids. This system mild robust, offering excellent selectivity across broad range substrates high regio- stereoselectivity. Furthermore, this strategy opens up vast opportunities

Язык: Английский

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Merging radical catalysis and noncovalent stereocontrol concepts to forge native O-glycosidic linkages

Science Bulletin, Год журнала: 2024, Номер 69(21), С. 3308 - 3310

Опубликована: Авг. 30, 2024

Язык: Английский

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