Trifluoromethyl iodide

The main preparative techniques used to make all seven trifluoromethyl-quiaoline isomers iaclude copper-assisted coupliag of the haloquiaoliae with trifluoromethyl iodide (112) quiaoliaecarboxyhc acid with sulfur tetrafluoride—hydrogea fluoride (434,445) and aminoben2otrifluoride and glycerol... 

Trifluoromethylation is the most important perfluoroalkylation reaction. The initial work was earned out with trifluoromethyl iodide and copper metal in the... 

N 14.15% a deep blue solid, liq, or gas. The color of the liq is described as that of a coned ammoniacal Cu soln (Ref 2). The odor is described as earthy or similar to sewage sludge (Ref 2). Mp -196.6°, bp -84° (Refs 1 2) CA Registry No 334-99-6 Preparation. It was first isolated as a by-prod from the fluorination of Ag cyanide. Its formation was attributed to the presence of Ag nitrate or Ag oxide in the tech grade Ag cyanide used (Ref 2). The first prepn in good yield was by the irradiation in a sealed tube of a mixt of nitric oxide and trifluoromethyl iodide plus a small amt of Hg with the light from a Hg vapor lamp, yield 75% (Ref 3). 

Other alkylgold(III) compounds are [Au2(/r-X)2(CF3)4] (X = Br, I) synthesized by co-condensation of gold with CF3Br and CF3I, respectively, and may be sublimed at room temperature.1654 Trifluoromethylated compounds are potentially useful precursors for CVD studies as they are expected to show enhanced volatility.1655 m-[Au(CF3)2I(PMc3)] is formed in quantitative yield by oxidative addition of trifluoromethyl iodide to [Au(CF3)(PMe3)], the reaction is proposed to proceed via radical intermediates.1524,1656... 

Alone, or Air, or Hydrogen, or Carbon monoxide or Allyl bromide, or Trifluoromethyl iodide... 

Biphenylyl ditelluride 33 was treated with sodium borohydride/methanol in the presence of trifluoromethyl iodide or bromide in tetrahydrofuran (THF) to give trifluoromethyl biphenylyl telluride 34 (Eq. 7). 

Treatment of 5-salt 17 with sodium iodide gave trifluoromethyl iodide (Eq. 30). Irradiation with a high-pressure Hg lamp readily produced trifluoromethyl iodide in the same yield. 

An analogous reaction occurs between trifluoromethyl iodide and elementary phosphorus, arsenic, antimony, sulphur or selenium (5). The experimental procedure was the same in each case, the fluoroalkyl iodide being heated in a sealed tube or autoclave with the clement in question at temperatures ranging from 170 to 280°. Table 4 shows the products of these reactions which have been isolated. 

In the reaction between trifluoromethyl iodide and selenium at 265—290° bistrifluoromethyl selenide, (CF3)2Se, and bistrifluoromethyl diselenide, (CF3)2Sea, are produced in yields of 40 and 20% respectively (Table 4). These two compounds show a number of interesting reactions. The compound (CF3)2Se is converted quantitatively to CF3CI and, SeCl4 when irradiated in a quartz vessel with ultraviolet light. If the irradiation is done in Pyrex, however, a new solid compound CFjSeClg is formed, which hydrolyses to the crystalline acid CF3SeO(OH) (m.p. 118°). The... 

It has recently been reported that rhodium catalysts (Rh Cl(PPh3)3) are able to mediate the addition of trifluoromethyl iodide, in the presence of Et2Zn, onto the position of... 

An intramolecular cycloaddition occurred, when 2-alkylidene-l,3-dithianes having a hydroxy group at an appropriate distant position (3- or 4-atoms) were treated with trifluoromethyl iodide in the presence of SO2. A radical mechanism with 2-alkyl-2-iodo-l,3-dithianes as intermediates is suggested (Equation 37) <1997JOC9107>. 

Trifluoromethyl iodide is a poor substrate for SN2 reactions [28], The increased donativity of the methylene carbon as rendered by the fluorine atoms is reflected in its reluctance to enter a bonding relationship with a nucleophile. Similar reactivity patterns are known for chloromethyl phenyl sulfone [28] and chloromethyltrimethyl-silane. In these latter compounds the reactive center is directly linked to an acceptor group. 

Trifluoromethylation is the most important perfluoroalkylation reaction. Kobayashi and co-workers reported the trifluoromethylation of aryl, vinyl, alkyl halides with trifluoromethyl iodide in the presence of copper powder in aprotic solvents such as HMPA at 120-150 °C [83,84], and this methodology has been applied to the preparation of fluorinated pyrimidine and purine nucleosides [85,86] (Scheme 27). 

Due to the cost of trifluoromethyl iodide, other cheaper sources have been investigated for trifluoromethylation. Sodium trifluoroacetate reacted with aryl iodide in the presence of copper (I) iodide in NMP at 140 -160 °C to afford the corresponding coupling product [87]. No trifluoromethylation was observed without Cul. Under similar reaction conditions, sodium pentafluoropro-pionate worked well to give the pentafluoroethylated compounds [88, 89] (Scheme 28). 

UV irradiation of steroidal dienones in the presence of trifluoromethyl iodide allows the selective introduction of a trifluoromethyl group a to the carbonyl function [140] (equation 121)... 

Trifluoromethyl iodide, 599 Trifluoromethylzinc iodide, 599 Trifluoroperacetic acid, 560 Triisobutylaluminum-bis(N-... 

Trifluoromethylation.5 Ultrasonically dispersed zinc in DMF or THF reacts with trifluoromethyl iodide to form trifluoromethylzinc iodide, which adds as formed to aldehydes or ketones (equation I). 

The photodissociation of trifluoromethyl iodide, CF3I —> CF3 + I/I, which was briefly discussed in Section 6.4, seems to illustrate case (a) of Figure 9.4 while the photo dissociation of methyl iodide, CH3I —> CH3 + I/I, appears more to represent case (b). In both examples, the 1/2 umbrella mode, in which the C atom oscillates relative to the Irrespectively F3-plane, is predominantly excited. Following Shapiro and Bersohn (1980) the dissociation of CH3I and CF3I may be approximately treated in a two-dimensional, pseudo-linear model in which the vibrational coordinate r describes the displacement of the C atom from the H3-/F3-plane and the dissociation coordinate R is the distance from iodine to the center-of-mass of CH3/CF3 (see Figure 9.6).t... 

The reactions of trifluoromethyl iodide with the main group elements and elemental mercury were extensively investigated by Eme-leus and his students almost as soon as the reagent became available in quantity. Trifluoromethyl iodide was shown to readily oxidize a number of elements, most notably those below nitrogen in Group VA, and the trifluoromethyl ligand was observed to possess a considerable amount of pseudohalogen character (5). 

The first successful syntheses utilizing trifluoromethyl iodide in transition metal chemistry were reported by Stone and his students. Stone reasoned that if CF3I would not react with transition metal anions to form trifluoromethyl derivatives [see Eq. (3)] then perhaps compounds containing perfluoroalkyl substituents could be generated by the oxidative addition of perfluoroalkyl halides to low valent transition metal substrates (9,10). The first reported trifluoromethyl-substi-tuted transition metal complex prepared by this route is shown in Eq. (4) (41). 

The reaction of CF3I with low valent metals is remarkable for the very mild conditions that are required. Typically, trifluoromethyl iodide and the transition metal species are maintained at ambient temperatures for periods of time which range from a few minutes to a few days. When employed at all, solvents are noninteractive and, at most, only gentle heating is required. The utility of oxidative addition reactions with trifluoromethyl iodide has been demonstrated in numerous systems and representative examples are presented in Table II. 

Place zinc powder (1.3 g, 20 mmol), trifluoromethyl iodide (3 g, 30 mmol), benzaldehyde (1.06 g, 10 mmol), and /V,/V-dimethylformamide (dry, 30 mL) in a flame dried round-bottom flask, which is equipped with a dry ice acetone condenser. 

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