Copper‐Catalyzed Trifluoromethylation of Unactivated Olefins

Abstract

Activating the inactive: A copper‐catalyzed allylic trifluoromethylation of unactivated terminal olefins proceeds under mild conditions to produce linear allylic trifluoromethylated products with high E/Z selectivity (see scheme). The reaction can be applied to a range of substrates bearing numerous functional groups. Furthermore, the reaction is scalable and amenable to a benchtop setup.

Recent progress in the trifluoromethylation of alkenes with Togni's reagents

“…In 2011, the groups of Buchwald 23 and Wang 24 showed that Togni's reagents can be used as a clean source of the CF 3 radical for the trifluoromethylation of alkenes. These trifluoromethylations rely on Cu(I) catalysis, and experimental evidence for the involvement of free CF 3 radicals was provided (Scheme 2).…”

“…A proposed mechanism for this trifluoromethylation reaction is depicted in Scheme 3. Reaction of Togni's reagents with a copper catalyst generates a CF 3 radical (Scheme 2), 23,24 followed by radical addition and single-electron oxidation to give intermediate C. 26 Subsequent trapping of the carbocation C with a nucleophile leads to the desired product D. It is assumed that trifluoromethylation of olefin substrate E might be achieved using a copper-based strategy involving the generation of an allylic radical and a subsequent CF 3 transfer (Scheme 3, Path A). [27][28][29] Alternatively, if Togni's reagent 1 could be used as an electrophilic CF 3 ·equivalent, the final product F may be generated through an atom transfer radical addition type pathway (Scheme 3, Path B).…”

Recent Progress in Copper Catalyzed C—H Functionalizations

“…该反应将邻羟 基取代苯乙烯的 C-O 偶联与氟代芳环的 C-H 键活化 反应组合, 用以制备不同的 2-(多氟代苯)苯并呋喃衍生 物(25) [20] . 氟烷基是很多药物和天然产物中的重要结构基团, 最近 Loh 等 [21] 报道了首例亚铜催化的烯酰胺的直接 C-H 键活化三氟甲基化反应(Scheme 3), 为有机底物的氟 烷基化反应 [22] 提供了新思路. 该反应的官能团耐受性 运用该方法, 他们 [24] 成功合成了一种荧光染料 43 (Eq.…”

An Improved Copper‐Mediated Oxidative Trifluoromethylation of Terminal Alkynes

“…In view of the importance of trifluoromethylated olefins and alkynes, several groups have recently developed efficient methodologies for the direct trifluoromethylation of unactivated olefins and alkynes. Buchwald [15] followed by Wang [16] described the Cu-catalyzed trifluoromethylation of terminal olefins by using the Togni electrophilic trifluoromethylation reagent. Using Umemoto's reagent and catalyzed by (thiophene-2-carbonyloxy)copper in the presence of 2,4,6-collidine, Liu and co-workers [17] reported another method for the trifluoromethylation of terminal alkenes.…”