Sunlight-driven trifluoromethylation of olefinic substrates by photoredox catalysis: A green organic process
作者:Munetaka Akita、Takashi Koike
DOI:10.1016/j.crci.2015.01.013
日期:2015.7
types of catalytic photoredox processes following the reductive quenching cycle (RQC) and the oxidative quenching cycle (OQC), the discussion is focused on organic transformations based on OQC, in particular the trifluoromethylation of olefinic substrates with electrophilic trifluoromethylating reagents furnishing solvolytic addition products and substitution products. It is concluded that catalytic
Radical Desulfur‐Fragmentation and Reconstruction of Enol Triflates: Facile Access to α‐Trifluoromethyl Ketones
作者:Xiaolong Su、Honggui Huang、Yaofeng Yuan、Yi Li
DOI:10.1002/anie.201608507
日期:2017.1.24
efficient oxidative radical desulfur‐fragmentation and reconstruction of enoltriflates for the synthesis of α‐CF3 ketones. Preliminary mechanistic studies disclosed that oxidative fragmentation to release a CF3 radical from the triflyl group of enoltriflate and subsequent addition of the CF3 radical to another enoltriflate form the desired α‐CF3 ketones. This method provides a new approach to α‐CF3
Visible light induced Trifluoromethyl Migration: Easy Access to α-Trifluoromethylated Ketones from Enol Triflates
作者:Shuyang Liu、Jiyang Jie、Jipan Yu、Xiaobo Yang
DOI:10.1002/adsc.201701051
日期:2018.1.17
Herein, we reported a novel method to synthesize α-trifluoromethylated ketones from enol triflates. Involving a cascade sulfurdioxide extrusion and a CF3 (trifluoromethyl) radical addition process, this reaction proceeds at room temperature and is driven by visible light irradiation. This protocol bears good functional group compatibility, which can generate the desired products in good to excellent
organic compounds with a trifluoromethyl group. A new and facile synthesis of ketones with a trifluoromethyl substituent in the α‐position proceeds through a one‐potphotoredox‐catalyzed trifluoromethylation–oxidation sequence of aromatic alkenes. Dimethyl sulfoxide (DMSO) serves as a key and mild oxidant under these photocatalytic conditions. Furthermore, an iridium photocatalyst, fac[Ir(ppy)3] (ppy=2‐phenylpyridine)
reagents (trifluoromethyl)(4-nitrophenyl)bis(carbomethoxy)methylide (1g) and (trifluoromethyl)(3-chlorophenyl)bis(carbomethoxy)methylide (1j) through structure-activity study was described. Under mild conditions, reagent 1g reacted with β-ketoesters and silyl enol ethers to give α-trifluoromethylated-β-ketoesters or α-trifluoromethylated ketones in high yields. In addition, reagent 1g could serve as