Photoredox-Catalyzed Tandem Radical Cyclization of N-Arylacrylamides: General Methods To Construct Fluorinated 3,3-Disubstituted 2-Oxindoles Using Fluoroalkylsulfonyl Chlorides

Abstract

Fluorinated radicals were generated from RfSO2Cl by photoredox catalysis under mild conditions, where Rf = n-C4F9, CF3, CF2H, CH2F, CH2CF3, and CF2CO2Me. This method provided a general way to construct fluorinated 2-oxindoles from reaction with N-arylacrylamides via a proposed tandem radical cyclization process.

Efficient Cu‐catalyzed Atom Transfer Radical Addition Reactions of Fluoroalkylsulfonyl Chlorides with Electron‐deficient Alkenes Induced by Visible Light

“…Likewise, comparison of the yields of esters 3 ag-3 ai indicated that the reactivity of phenyl acrylate was greater than those of the alkyl acrylates. As for the Narylmethacrylamide substrates 2 v or 2 w, which we have used previously in tandem radical cyclization studies, [18] ATRA adducts 3 av and 3 aw were still observed as the main products in 78 % and 92 % yields, respectively. It should be noted that CF 3 Cl ( 19 F NMR: À28 ppm) was detected as a byproduct in all of these reactions.…”

“…[18] On the basis of that work, we came to believe that photoinduced ATRA reactions of fluoroalkylsulfonyl chlorides with electron-deficient alkenes might be possible.…”

Advances in Photocatalysis: A Microreview of Visible Light Mediated Ruthenium and Iridium Catalyzed Organic Transformations

“…The scope was expanded to include the use of the CF 2 H radical, though it required a change of photocatalyst to 1 . 66 …”

Recent advances in photoinduced trifluoromethylation and difluoroalkylation

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Please do not adjust margins Please do not adjust margins cyclization would produce trifluoromethylated heterocycles in one pot with high efficiency under mild conditions. Dolbier and co--workers 38 found that α,β--unsaturated amides were good partners to accept the radical addition of fluoro--containing radicals in the presence of photocatalyst (Scheme 29). Several fluoroalkylsulfonyl chlorides were examined and it was found that different fluoro sources needed different photocatalysts.…”