Photo-organocatalytic Synthesis of β-Keto Sulfonyl Fluorides via Radical Fluorosulfonylation of Vinyl Acetates

Abstract

A metal-free synthesis of useful β-keto sulfonyl fluorides has been established via radical fluorosulfonylation of ketone-derived vinyl acetates under photoredox organocatalysis by using 1-fluorosulfonyl benzoimidazolium (FABI) as the fluorosulfonyl radical source and oxygen-doped anthanthrene (ODA) as the photocatalyst. A series of aryl and alkyl β-keto sulfonyl fluorides as well as cyclic analogues can be readily obtained in moderate to high yields from widely available ketone starting materials.

Recent advances in photochemical and electrochemical strategies for the synthesis of sulfonyl fluorides

“…Liao and colleagues reported several radical fluorosulfonylation reactions to construct diverse sulfonyl fluorides (Scheme 19) using the same redox-active FABI as the sulfonyl fluoride radical precursor and a photocatalyst. These reactions included radical fluorosulfonylation of alkenes/intramolecular arylation via a cascade reaction to access FSO 2 -functionalized chromanes, 54 radical fluorosulfonylation of vinyl acetates, 55 radical fluorosulfonyl heteroarylation of unactivated alkenes with quinoxalin-2(1 H )-ones, 56 and a FSO 2 radical-initiated tandem addition reaction of two different olefins. 57…”

Photoredox Annulation of Polycyclic Aromatic Hydrocarbons

“…At the synthetic planning level, this consideration guided us to contemplate the photoredox approach to mildly generate the given aryl radical intermediate. Our group first reported the use of peri -xanthenoxanthene ( PXX ) as a strong and low-cost photoreducer (E 1/2 (PXX •+ /PXX*) = −2.00 V vs SCE; E 1/2 (PXX*/PXX •– ) = +0.61 V vs SCE upon irradiation at 450 nm) to generate reactive radical species from electron-poor aryl and alkyl halides. − Considering that PXX could enable a variety of different transformations (e.g., dehalogenation; C–C, C–S, and C–N bond formation; iododifluoromethylation of alkenes; polymerization of olefins; and fluorosulfonylation reactions − ), we hypothesized that PXX could also be used as a photocatalyst to activate the reduction of a suitable electron-deficient aryl moiety into a radical intermediate that would undergo intramolecular C–C bond formation with a neighboring aryl substituent (Scheme e).…”

Photoreduction of Anthracenes Catalyzed by peri‐Xanthenoxanthene: a Scalable and Sustainable Birch‐Type Alternative

“…Recently, the groups of Dilman and Liao expanded the use of PXX as a photocatalyst. Whereas the former group used PXX to promote iododifluoromethylation of alkenes, [28] the latter photocatalyzed the polymerization of olefins [29] and different types of fluorosulfonylation reactions [30–33] . Interestingly, both the organocatalytic atom transfer radical polymerization (O‐ATRP) and the radical fluorosulfonylation of ketone‐derived vinyl acetates could be performed under sunlight.…”