Trifluoroethyl triflate

Applying Danheiser s method (96JOC134), phenyldiazenyl ketone 67 reacts with lithium bis(trimethylsilyl)amide in absolute tetrahydrofuran followed by 2,2,2-trifluoroethyl triflate forming a mixture of C- and O-triflate intermediates 68 and 69, respectively. Upon treatment with mesyl azide, the mixture of 68 and 69 provides the desired l-diazo-4-methyl-4-[(E)-phenyldiazenyl]pentan-2-one (58) as yellow crystals in very good yield (87%) (Scheme 16). 

Alkyl and aryl thiols afforded with perfluoroalkyl iodonium salts in the presence of pyridine the corresponding sulphides in good to excellent yields [25], Several sulphides and sulphoxides upon reaction with trifluoroethyl phenyliodonium triflate were converted into 2,2,2-trifluoroethyl sulphonium salts [26]. 

The preparation of the l-aryl-2,2,2-trifluoroethyl tosylates I—III and the mesylate IV was described (11-16) as well as the solvolytic rate constants of these derivatives in a range of solvents (11-16). Solvolytic and polarimetric rate constants were also obtained for optically active 1-phenyl-2,2,2-tri-fluoroethyl triflate Va and solvolytic rate constants for the a-deuterated analogue Vb (11). Solvolytic and polarimetric rate constants were also measured for optically active Vla-c (17). 

DesMarteau and coworkers reported the preparation, X-ray crystal structure and chemistry of trifluo-roethyliodonium salts 391 by the reaction of fluoroalkyliodo-bis(trifluoroacetates) 389 with benzene and triflimide acid (390) (Scheme 2.113) [68,531,532], The structure of trifluoroethyl(phenyl)iodonium salt 391 (n = 1) was established by a single-crystal X-ray analysis [68], In contrast to fluoroalkyliodonium triflates 383, compounds 391 are stable to water and can be used as reagents for fluoroalkylation reactions in aqueous media. 

Banks RE, Mohialdin SN (1988) Synthesis of indoUzines from N-(2,2,2-trifluoroethyl)-pytidinium triflate evidence for the generation of pyridinium (trifluoromethyl)methylide. 

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