Direct Preparation of Trifluoromethylindium Reagents from Trifluoromethyl Iodide: Effective Trifluoromethylation and Perfluoroalkylation Reagents

Abstract

The direct synthesis of trifluoromethylindium reagents prepared from trifluoromethyl iodide by using just one equivalent each of indium, lithium chloride or sodium iodide, and ferrocene is reported. The weak In···F interaction is suitable to prepare stable but nucleophilic perfluoroalkyl reagents, which were successfully employed in the perfluoroalkylation of aldehydes. Notably, the nucleophilic trifluoromethylation of various aldehydes took place with trifluoromethyl iodide by utilizing just one equivalent each of indium, lithium chloride, and ferrocene.

Condensed‐Phase, Halogen‐Bonded CF3I and C2F5I Adducts for Perfluoroalkylation Reactions

“…Examples in perfluoroalkylation include the Ruppert-Prakash reagent (Me 3 SiCF 3 ), [2] the Trifluoromethylator reagent ("CF 3 Cu"), [3] the Langlois reagent (CF 3 SO 2 Na), [4] the Baran reagent Zn(SO 2 CF 3 ) 2 , [5] the Umemoto reagent (S-(trifluoromethyl)dibenzothiophenium), [6] and the Togni reagents. [7] Perfluoroalkyl iodides, in particular CF 3 I, [8][9][10][11][12][13][14] are useful and inexpensive sources of perfluoroalkyl fragments. [1b,d, 15] However, CF 3 I and C 2 F 5 I are gases, making accurate measurement cumbersome.…”

“…Trifluoromethyl iodide is a common trifluoromethylation reagent. [8][9][10][11][12][13][14] Despite its utility and low cost ($ 110 per mol from Oakwood Products), routine use by synthetic chemists has been challenging due to its boiling point of À22.5 8C. The handling process is impractical, time consuming, and imprecise in the measurements of small quantities, when compared to the other more conveniently handled reagents mentioned above.…”

Metal-mediated radical perfluoroalkylation of organic compounds

“…Indium has been demonstrated to be an efficient and promising metal for organic reactions in aqueous media [65]. Indium has recently been used as an ET agent in the perfluoroalkylation of aromatic aldehydes in DMF as solvent employing iodoperfluoroalkanes [66]. Some additives such as LiCl or LiBr are used to increase the reaction yields.…”

“…Aldehydes undergo perfluoroalkylation with the use of In reagents and perfluoroalkyl iodides by using 1 equiv. of indium, lithium chloride or sodium iodide, and ferrocene [66]. The reaction is depicted in Scheme 27.…”

4-Pyridyl perfluoroalkyl sulfide as a practical nucleophilic perfluoroalkylation reagent

“…Perfluoroalkyl metal species have been recognized as a typical nucleophilic perfluoroalkylation reagent in the past two decades. Perfluoroalkyl titanium, 10 indium, 11 and zinc 12 , 13 reagents were developed by Mikami, [10][11][12] Uchiyama, 13 and other groups. These organometallic reagents exhibit good reactivity towards electrophiles, though most of them are not bench-stable and need to be prepared prior to use.…”