Recent advances in direct trifluoromethylation of olefinic C–H bonds

Abstract

The aim of this review is to provide a comprehensive overview of the direct trifluoromethylation of olefinic C–H bonds with special attention on the mechanistic aspects of the reactions.

Recent Development of Trifluoromethyl Reagents: A Review

“…A few of them are concentrated on specific areas such as Umemoto's reagent [21], reactions in aqueous media [31], hypervalent iodine reagents [32], CF 3 -S transfer agents [33] and photolytic reactions [34]. Further, a few reviews have been discussed fluorine effect on chemical reactions [35] and in some reviews, it is described some selective trifluoromethylated reactions [36][37][38][39]. Although, a good number of review articles are available, sometimes it is difficult to extract important ideas from the vast amount of discussion.…”

F–-Free Deoxyhydrotrifluoromethylation of α-Keto Esters with Ph3P+CF2CO2–: Synthesis of α–CF3-Substituted Esters

“…Trifluoromethyl (CF 3 )-containing organic compounds do not exist in natural products . The development of efficient synthetic methodologies for the incorporation of the CF 3 group into organic molecules has received more attention in recent years . Owing to its unique physical, chemical, and biological properties, the CF 3 group can substantially alter an organic molecule’s lipophilicity, metabolic stability, and ability to cross the blood–brain barrier; trifluoromethylated compounds have found wide applications in the fields of medical, pharmaceutical, agricultural, and material sciences …”

“…Although significant advancements in this field have been made in the direct introduction of the CF 3 group into organic moieties, such as nucleophilic, electrophilic, and free radical reactions, the methods for the synthesis of functionalized α-trifluoromethylated carboxylic acid esters are still relatively limited. − In addition, α-trifluoromethylated carboxylic acids have been identified as bioactive compounds and versatile intermediates in synthetic chemistry. To this end, a few elegant works showed that the synthesis of α-CF 3 esters could be achieved by the reaction of ester derivatives, α-diazo esters, and sensitive ketene silyl acetals with Togni’s reagent and Umemoto’s reagent, , CF 3 I and TMSCF 3 (Scheme a).…”

Radical Pentafluoroethylation of Unactivated Alkenes Using CuCF2CF3

“…Fluoroalkylation of unactivated alkenes constitutes one of the most efficient and versatile strategies for synthesizing high-value fluorinated molecules. , Being among the most abundant chemical feedstocks in organic synthesis, simple alkenes are readily available in large quantities at low costs, and their characteristic reactivity profile enables a wide range of functionalization for constructing carbon–carbon and carbon–heteroatom bonds . In this regard, direct trifluoromethylation of unactivated alkenes allows the introduction of the smallest perfluoroalkyl group, CF 3 , into organic molecules with high efficiency, selectivity, and atom economy . For instance, the challenging allylic Csp 3 –CF 3 bond formation has been achieved by elegant copper-catalyzed trifluoromethylation of unactivated alkenes 1 (Scheme a) .…”