Study of a Stable “Trifluoromethoxide Anion Solution” Arising from 2,4‐Dinitro‐Trifluoromethoxybenzene

Abstract

Despite recent advances, trifluoromethoxylation remains a challenging reaction. Here we describe an efficient trifluoromethoxylative substitution, using an inexpensive and easy-to-handle reagent. By mixing DMAP with a slight excess of 1,4-dinitro-trifluoromethoxybenzene (DNTFB), a stable solution of trifluoromethoxide anion is obtained and can be used to perform a S N 2 reaction without any silver additives. A precise study of the properties and behavior of this unusual stable solution of CF 3 O À species is also performed.

Study of Carbamoyl Fluoride: Synthesis, Properties and Applications

“…Recently, we described an efficient preparation of a stable solution of trifluoromethoxide anion ( 1 ) from inexpensive 2,4‐dinitrotrifluoromethoxybenzene (DNTFB) [14] . This anion is known to be able to collapse into difluorophosgene upon losing the fluoride anion.…”

“…[a] C. Bonnefoy, Dr. F. Toulgoat, Dr. T Recently, we described an efficient preparation of a stable solution of trifluoromethoxide anion (1) from inexpensive 2,4dinitrotrifluoromethoxybenzene (DNTFB). [14] This anion is known to be able to collapse into difluorophosgene upon losing the fluoride anion. Therefore, we hypothesized that the NÀ H of the amines could help to promote such a dissociation, thereby generating, in situ, C(O)F 2 which could then react with amines to ultimately provide the expected carbamoyl fluorides.…”

Trifluoromethoxylation Reactions of (Hetero) arenes, Olefinic Systems and Aliphatic Saturated Substrates

“…Reagent 4 (Figure 3) has profusely been employed in numerous nucleophilic trifluoromethoxylation reactions [21,52,58–60] . For instance Liu and colleagues achieved the Co‐catalyzed ring opening‐trifluoromethoxylation of racemic epoxides employing trifluoromethyl arylsulfonates (Figure 6A) [61,62] . The recently discovered nucleophilic reagent 6 [47] (Figure 3) allows for the substitution of alkyl halides (Cl, Br, and I) with the OCF 3 group in the absence of silver salts, a protocol substantially improved with respect to other nucleophilic strategies, which rely on the use of metals to boost the CF 3 O−M bond covalence (Figure 6B).…”

“…[21,52,[58][59][60] For instance Liu and colleagues achieved the Co-catalyzed ring opening-trifluoromethoxylation of racemic epoxides employing trifluoromethyl arylsulfonates (Figure 6A). [61,62] The recently discovered nucleophilic reagent 6 [47] (Figure 3) allows for the substitution of alkyl halides (Cl, Br, and I) with the OCF 3 group in the absence of silver salts, a…”

N-Trifluoromethoxyphthalimide: A Shelf-Stable Reagent for Nucleophilic Trifluoromethoxylation

“…On the other hand, the vigorous development of trifluoromethoxylating reagents has laid the foundation for more efficient synthetic methods. The classical nucleophilic trifluoromethoxylating reagents mainly include trifluoromethoxide salts, such as AgOCF 3 , CsOCF 3 , tris­(dimethylmino)­sufonium trifluoromethoxide (TASOCF 3 ), R 4 NOCF 3 , PyOCF 3 , etc. (Figure , top).…”