Photoinduced Trifluoromethylation with CF₃Br as a Trifluoromethyl Source: Synthesis of α-CF₃-Substituted Ketones

Abstract

An efficient and novel photoinduced trifluoromethylation employing CF 3 Br as a trifluoromethyl source is described. With commercially accessible fac -Ir (III) (ppy) 3 as the catalyst, radical trifluoromethylation between O -silyl enol ether and CF 3 Br occurs successfully. This method provides various α-CF 3 -substituted ketones with a broad substrate scope in good yields under mild reaction conditions.

Visible light/copper catalysis enabled alkylation of silyl enol ethers with arylsulfonium salts

“…On the basis of these preliminary results and together with the previous reports, 16 a possible reaction mechanism for this process was proposed (Fig. 2).…”

Recent advances in transition metal-mediated trifluoromethylation reactions

“…Hu and co-workers employed CF 3 Br as a trifluoromethyl source to demonstrate trifluoromethylation of O -silyl enol ether, affording the α-CF 3 -substituted ketones under photoredox catalysis (Scheme 56). 113 They employed fac -Ir III (ppy) 3 as a photocatalyst under the influence of blue light at room temperature to afford the desired trifluoromethylated product.…”

Visible‐Light Promoted Radical Fluoroalkylation of O‐ and N‐Substituted Alkenes

“…Fluorinated alkyl bromides have also been involved in reactions with silyl enol ethers. Thus, TIPS‐enolates couple with trifluoromethyl bromide in the presence of fac ‐Ir(ppy) 3 even without tertiary amine [43] . However, for bromides bearing two fluorines, a stronger photocatalyst should be used.…”