Photocatalytic fluorosulfonylation of aliphatic carboxylic acid NHPI esters

Abstract

Sulfonyl fluorides have been increasingly favored by medicinal chemists and chemical biologists because of their unique reactivity and stability, but their synthetic methods still have certain limitations. Based on the...

Synthetic strategies for fluorosulfonylated compounds: application to click chemistry reactions

“…Nie and collaborators 69 reported on a photocatalytic methodology for accessing aliphatic sulfonyl fluorides based on visible light-mediated photocatalyzed decarboxylative fluorosulfonylation of aliphatic NHPI esters. Optimized reaction conditions were achieved when Ir[(dF(CF 3 )ppy] 2 (dtbbpy)PF 6 ([Ir III ]) was employed as a photocatalyst, N -ethyldiisopropylamine (DIPEA) as a sacrificial reductant, and DABSO as a SO 2 source, in isopropanol as solvent and under blue light irradiation in an Ar atmosphere.…”

“…The methodology proved to work very satisfactorily with a variety of primary, secondary, and tertiary carboxylic acid NHPI esters, including derivatives of pharmacologically active drugs such as oxaprozin and flurbiprofen, among others (Scheme 17). Regarding the reaction mechanism, the authors 69 proposed a reductive photocatalytic cycle mediated by the [Ir III ] photocatalyst. Upon light excitation, the excited [Ir III ]* undergoes a single electron transfer process with DIPEA affording the [Ir II ] species and DIPEA˙ + .…”

Visible-light-driven reactions for the synthesis of sulfur dioxide-inserted compounds: generation of S–F, S–O, and S–N bonds

“…Another study using redox-active N -hydroxyphthalimide (NHPI) esters of aliphatic carboxylic acid as precursors for synthesis of sulfonyl fluoride was reported by Nie and co-workers in 2022. 84 Instead of direct utilization of SO 2 F from vinyl sulfonyl fluoride as in the previously reported method, 73 multicomponent reactions between NPHI ester, DABSO, and NSFI in the presence of Ir[dF(CF 3 )ppy] 2 (dtbbpy)PF 6 as a photocatalyst and DIPEA as a reductant under blue LED in i PrOHs at room temperature were carried out to give sulfonyl fluorides ( Scheme 22 ). Various NHPI esters of carboxylic acids including primary, secondary, and tertiary derivatives were successfully employed for fluorosulfonylation.…”

Photosynthesis of 3-Alkylated Coumarins from Carboxylic Acids Catalyzed by a Na2S-Based Electron Donor–Acceptor Complex

“…The N -hydroxyphthalimide (NHPI) ester is the widely used carboxylic acid derivative because it can generate the active alkyl radical through a one-electron reduction process under oxidant-free and mild conditions . Over the past years, a number of visible-light-induced alkylation reactions with NHPI esters as the alkyl source without employing oxidizing agents have been established . Despite this progress, the NHPI esters have limited commercial availability and are too expensive for industrial and large-scale application.…”