Umemoto’s 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].

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... 

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]

We initially examined photocatalytic hydroxytrifluoromethylation of styrene (19a) with Umemoto s reagent 18b using [Ru(bpy)3](PF6)2 in a mixture of acetone and H2O (Scheme 15). As was expected, irradiation by blue LEDs (L = 425 nm) afforded the desired hydroxytrifluoromethylated product, 3,3,3-trifluoro-l-phenyl-1-propanol (20a), in a 96% yield as the sole regioisomer. Another photocatalyst, /ac-Ir(ppy)3, also promoted the present reaction in a manner similar to [Ru(bpy)3]... 

This somophihc isocyanide insertion reaction is also suitable for use with hydrazines [48], arylsulfonyl chlorides [49], diaryliodonium salts [50], and Umemoto s reagent [50] (Scheme 13.22). Polycyclic quinoxalines can also be synthesized by the visible-light-induced decarboxylative radical cyclization of... 

Gade reported the asymmetric trifluoromethylation of (3-ketoesters using copper catalysis in the presence of bisoxazoline ligands. Here, either Togni s or Umemoto s reagent was required as the CF3 electrophile source. Sodeoka " reported the copper catalysed trifluoromethylation of allylsilanes, as did... 

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