Iron-catalyzed fluoroalkylative alkylsulfonylation of alkenes via radical-anion relay

• Published in: Nature communications Vol. 15; no. 1; p. 1480
• Main Authors: Hou, Xiaoya, Liu, Hongchi, Huang, Hanmin
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17.02.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/638/403/933; 639/638/549/933; 639/638/77/888; Alkenes; Anions; Carbon; Catalysis; Catalysts; Chemistry; Halides; Humanities and Social Sciences; Hydrocarbons; Intermediates; Iron; Ligands; Metals; multidisciplinary; Raw materials; Reducing agents; Relay; Science; Science (multidisciplinary); Sodium dithionite; Stoichiometry; Sulfur; Sulfur dioxide; Transition metals
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-45867-y

Transition metal-catalyzed reductive difunctionalization of alkenes with alkyl halides is a powerful method for upgrading commodity chemicals into densely functionalized molecules. However, super stoichiometric amounts of metal reductant and the requirement of installing a directing group into alkenes to suppress the inherent β-H elimination bring great limitations to this type of reaction. We demonstrate herein that the difunctionalization of alkenes with two different alkyl halides is accessible via a radical-anion relay with Na 2 S 2 O 4 as both reductant and sulfone-source. The Na 2 S 2 O 4 together with the electron-shuttle catalyst is crucial to divert the mechanistic pathway toward the formation of alkyl sulfone anion instead of the previously reported alkylmetal intermediates. Mechanistic studies allow the identification of carbon-centered alkyl radical and sulfur-centered alkyl sulfone radical, which are in equilibrium via capture or extrusion of SO 2 and could be converted to alkyl sulfone anion accelerated by iron electron-shuttle catalysis, leading to the observed high chemoselectivity. Stoichiometric amounts of metal reductant and the requirement of a directing group limit the application of transition metal-catalyzed reductive difunctionalization of alkenes with alkyl halides. Here, the authors report a reductive difunctionalization of alkenes via a radical-anion relay with Na 2 S 2 O 4 as both reductant and sulfone-source.