Study of a Stable "Trifluoromethoxide Anion Solution" Arising from 2,4-Dinitro-Trifluoromethoxybenzene

Phenylseleno trifluoromethoxylation of alkenes

Trifluoromethoxylated molecules and selenylated compounds find a wide range of interesting applications, but separately. In order to combine the potential of these two motifs and to propose a new class of compounds, we have developed an electrophilic phenylseleno trifluoromethoxylation of alkenes, which leads to β-selenylated trifluoromethoxylated compounds or, upon subsequent reduction, to the trifluoromethoxylated ones.

Catalyst-Free Trifluoromethoxylation of Silyl Enol Ethers and Allyl Silanes with Bis(trifluoromethyl)peroxide

Radical trifluoromethoxylation is an attractive approach to prepare compounds featuring the important OCF3 group, however most existing methods have focused on aromatic substrates. Here, we report novel methodologies with alkenyl substrates employing bis(trifluoromethyl)peroxide (BTMP) as a practical and comparatively atom economical trifluoromethoxylating reagent. With silyl enol ether substrates, switching reaction solvent allows for the synthesis of either α-(trifluoromethoxy)ketone products or unprecedented alkenyl-OCF3 species. Furthermore, allyl silanes have been employed as substrates for the first time, affording allyl(trifluoromethyl)ether products in good yields. In each case, the methods operate at room temperature without large excesses of the alkene substrate while, in contrast to previous radical trifluoromethoxylation reactions, no catalyst, light or other activators are required.

Deoxyfluorination of Carboxylic Acids via an In Situ Generated Trifluoromethoxide Salt

An in situ generated pyridinium trifluoromethoxide salt (PyOCF3) is a highly effective deoxyfluorination reagent for the synthesis of acid fluorides. PyOCF3 is formed at room temperature from the reaction of 2,4-dinitro(trifluoromethoxy)benzene with 4-dimethylaminopyridine. PyOCF3 undergoes slow release of fluorophosgene and fluoride, which serve as the electrophile and nucleophile, respectively, for deoxyfluorination. A wide substrate scope and high functional group tolerance are demonstrated. Furthermore, the acid fluorides can be purified by filtration and telescoped to various known reactions.

Recent Advances in the Synthesis and Transformation of Carbamoyl Fluorides, Fluoroformates, and Their Analogues

Carbamoyl fluorides, fluoroformates, and their analogues are a class of important compounds and have been evidenced as versatile building blocks for the preparation of useful molecules in organic chemistry. While major achievements were made in the synthesis of carbamoyl fluorides, fluoroformates, and their analogues in the last half of 20th century, an increasing number of reports have focused on using O/S/Se=CF2 species or their equivalents as the fluorocarbonylation reagents for the direct construction of these compounds from the parent heteroatom-nucleophiles in recent years. This review mainly summarizes the advances in the synthesis and typical application of carbamoyl fluorides, fluoroformates, and their analogues by the halide exchanges and fluorocarbonylation reactions since 1980.

Comprehensive Study and Development of a Metal-Free and Mild Nucleophilic Trifluoromethoxylation

Among the general interest in fluorinated compounds, trifluoromethoxylated molecules play a specific role. However, despite this interest, the development of efficient reagents to perform trifluoromethoxylation reactions remains a challenge. Here, 2,4-dinitro-trifluoromethoxybenzene (DNTFB) is used as a trifluoromethoxylating reagent to perform nucleophilic substitution under mild metal-free conditions with different leaving groups, including direct dehydroxytrifluoromethoxylation. A mechanistic study rationalized the reaction and subsequently proposed only three reaction conditions, depending on the reactivity of the starting substrates.

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

Due to the unique properties of the OCF₃ group, trifluoromethyl ether compounds play an important role in pharmaceuticals and agrochemicals. Recently, considerable attention has been focused on the development of practical and convenient reagents for the direct incorporation of the OCF₃ group into organic compounds. Herein, we reported a new trifluoromethoxylating reagent N-trifluoromethoxyphthalimide (Phth-OCF₃). The reagent was a stable solid and released an OCF₃ anion under mild reaction conditions. We demonstrated the application of Phth-OCF₃ for the nucleophilic trifluoromethoxylation of various alkyl electrophiles.

Study of Carbamoyl Fluoride: Synthesis, Properties and Applications

Carbamoyl fluoride is a fluorinated group that, to this date, remains underexplored, probably due to the lack of data concerning its properties. In this paper, a study of carbamoyl fluoride is presented. Stability studies, in particular under physiological conditions, and lipophilicity measurement were performed. A new easy, safe, inexpensive, and metal-free synthesis method is also described. Finally, a potential use in radiochemistry through a ¹⁸ F/¹⁹ F isotopic exchange is demonstrated.

Silver-Catalyzed Trifluoromethoxylation of Aziridines

We disclose a silver-catalyzed trifluoromethoxylation of N-tosyl aziridines with trifluoromethyl arylsulfonate. The protocol is characterized by its mild conditions, simple operations, and good chemo- and regioselectivity. In addition, the trifluoromethoxylation of trisubstituted aziridines could construct C-OCF₃ quaternary centers exclusively, which is quite rare. This method unlocks a new catalytic blueprint for accessing β-trifluoromethoxylated amines, which could be important building blocks in synthetic chemistry.