Umemoto reagents

Gouvemeur, whereby treatment of a broad range of allylsilanes in the presence of Togni or Umemoto reagents and 10 mol% of a copper(i) halide catalyst effected the desired transformation. Gouvemeur demonstrated that in the absence of the silicon group the reaction was low yielding and non-selective. 

T. Umemoto Perfluoroalkylation with (perfluoroalkyl)phenyliodonium trifluoromethanesulfonate (FITS) reagents [7]... 

Scheme 2.156 Synthesis of Umemoto s most reactive trifluoromethylating reagent,...

Scheme 2.157 Examples of applications of different types of Umemoto s reagent [29],...

Umemoto s reagents are soluble and stable in a variety of polar solvents, for example DMSO, DMF, acetonitrile, THF, or CH2CI2. A side product ofthe trifluoromethylation of any nucleophile is the formation of one equivalent of dibenzofuran, which is sometimes difficult to separate from the desired reaction product. To facilitate the work-up, zwitterionic dibenzothiophenium sulfonates were designed. 

Scheme 2.1S8 Trifluoromethylation with sulfonated Umemoto s reagents facilitate work-up of the reaction mixtures [30].

T. Umemoto, MFC Reagent Brochure, DAIKIN Fine Chemicals Research Center, Tokyo, 1997. 

Electrophilic Trifluoromethylation with Umemoto s Reagents A.8.1 Trifluoromethylation of the Trimethylsilyl Dienol Ether 30... 

Scheme A.12 Electrophilic trifluoromethylation with Umemoto s reagent [18].

Enolate Umemoto s reagent, FITS reagent Perfluoroolefm + F + RX generation of perfluor-oalkyl anion and subsequent nucleophilic replace- 129, 132 ff... 

In the last ten years Umemoto and his co-workers have developed a series of effective perfluoroalkylating agents, i.e. perfluoroalkylphenyliodonium trifluoromethanesulfonate (FITS, 12) reagents. We very briefly summarize below their synthesis and reactions. 

Fluoroalkyl(aryl)iodonium salts are the most stable and practically important class of alkyl(aryl)iodonium derivatives. The application of such salts as electrophilic fiuoroalkylating reagents was reviewed in 1996 by Umemoto [1017]. Perfluoroalkyl(phenyl)iodonium trifiates (FITS reagents) 764 are efficient perfluoroalky-lating reagents toward various nucleophiUe substrates, sueh as arenes, carbanions, alkynes, alkenes, carbonyl compounds, amines, phosphines and sulfides [1017]. Scheme 3.300 shows several representative examples of electrophilic perfluoroalkylations using FITS reagents. 

MA(-dimethylaiiilmes (equation 3) [32]. Independently, Liang reported a similar synthesis of 3-acylindoles [33]. Hon and colleagues uncovered a novel 3-trifluoromethyl-indole synthesis that used a CuBr-promoted reaction of 2-alkynylanihne in the presence of Umemoto s reagent (5) (equation 4) [34],... 

Photoaddition. Ir(ppy)3 (ppy = 2-phenylpyridine) was used as a photoredox catalyst in the oxyatylation, aminoarylation, and o [Pg.68]

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