Radical-mediated hydroxytrifluoromethylation of α,β-unsaturated esters

Strategies for nucleophilic, electrophilic, and radical trifluoromethylations

“…For example, OshimaUtimoto's group reported the reaction of CF 3 I with silyl and germyl enol ethers mediated by Et 3 B in the presence of nitrogen base such as 2,6-dimethylpyridine [132,133]. In 2003, Nagano and co-workers described the radical-mediated hydroxytrifluoromethylation of a,b-unsaturated esters in the presence of Et 3 B, water, and potassium fluoride in THF (Scheme 45) [134,135].…”

Synthesis of Halogenated Carboxylic Acids and Amino Acids

“…Earlier, the same group described the synthesis of a-hydroxy esters by hydroxytrifluoromethylation of unsaturated esters, though this process was not stereoselective. 90 The addition of perfluoroalkyl iodides to allenes was used to prepare unsaturated carboxylic acids with excellent E/Z selectivity (Scheme 68). 91…”

Effects of B2pin2 and PCy3 on copper-catalyzed trifluoromethylation of substituted alkenes and alkynes with the Togni reagent

“…A related addition/elimination type of reaction for CeH functionalization of alkenes has also been reported and studied. 15,16,28e31 Useful metal-free trifluoromethylation approaches involving photocatalysis or organocatalysis for oxytrifluoromethylation and related difunctionalization reactions were reported by Nagano, 32 Studer, 33 Akita, 34 Masson 35 and other groups. 26,36e40 As shown above a large number of excellent publications have appeared in the past years on development of new difunctionalization methods but the systematic studies of additive and substituent effects have received somewhat less attention.…”