[2314-97-8] · CF3I · Trifluoroiodomethane · (MW 195.91)
Alternate Name: trifluoromethyl iodide.
Physical Data: bp -22 °C.1
Solubility: sol ether, acetone, alcohol, benzene.
Form Supplied in: gas; commercially available.
Preparative Methods: prepared by the fluorination of CI4 with IF5 (eq 1),2 or by the Hunsdiecker reaction of Silver(I) Trifluoroacetate with an excess of Iodine (eq 2),3 or by the reaction of trifluoroacetyl fluoride with Lithium Iodide (eq 3).4 More recently, Chen reported a convenient method for the synthesis of CF3I by the reaction of XCF2CO2Me (X = Br, Cl) with iodine, KF, and CuI (eq 4).5
Radical addition of CF3I to alkenes and alkynes is initiated by irradiation,6 peroxide,6a metals,7 boranes,8 enzymes,9 and heating10 to give the corresponding adducts (eq 5). Enamines react with CF3I rapidly at room temperature without UV irradiation or initiator to form trifluoromethylated ketones after hydrolysis.11
Addition of CF3I to carbonyl compounds is promoted by metals and metal salts such as Zinc,12 Zn/MV2+ (MV2+ = methyl viologen),13 Tin(II) Chloride,14 Zn/ultrasound,15 and Magnesium16 to form the corresponding trifluoromethylated alcohols (eq 6).
In the presence of copper metal, CF3I undergoes coupling with aryl and vinyl iodides to afford the corresponding trifluoromethylated aromatics and alkenes, respectively.17 Pregenerated CF3Cu (from the reaction of CF3I with copper metal in HMPA at 120 °C) reacts with benzyl, allyl, vinyl, acyl, and alkyl bromides to give the corresponding trifluoromethylated products (eq 7).18
Photoreaction of CF3I with thiols in liquid NH3 gives the corresponding trifluoromethyl sulfides (eq 8).19
Trifluoromethylation of benzene, thiophene, pyridine, and imidazole has been accomplished via thermolysis or irradiation of CF3I in the presence of the appropriate aromatic compound (eq 9).20
Donald J. Burton & Weiming Qui
The University of Iowa, Iowa City, IA, USA