Mn-Mediated Electrochemical Trifluoromethylation/C(sp²)–H Functionalization Cascade for the Synthesis of Azaheterocycles

Abstract

A general electrohemical strategy for the combined trifluoromethylation/C­(sp2)–H functionalization using Langlois’ reagent as the CF3 source under oxidant-free conditions was developed. Using Mn salts as the redox mediator, this method provides an efficient and sustainable means to access a variety of functionalized heterocycles bearing a CF3 moiety. Detailed mechanistic studies are consistent with the formation of CF3-bound high oxidation state Mn species, suggesting a transition-metal-mediated CF3 transfer mechanism for this trifluoromethylation/C­(sp2)–H functionalization process.

Electrochemical Decarboxylative Trifluoromethylation of α, β‐Unsaturated Carboxylic Acids with CF3SO2Na

“…Further, the works on trifluoromethylative difunctionalization of alkenes by electrolysis of CF 3 SO 2 Na were disclosed by Cantillo, Lin, Lei, Xu, Pan, and Kim, respectively. Meanwhile, the electrochemical trifluoromethyl/cyclization of N ‐arylacrylamides with CF 3 SO 2 Na have also been demonstrated by Zeng, Mo, and Ackermann, respectively.…”

CF3SO2Na as a Bifunctional Reagent: Electrochemical Trifluoromethylation of Alkenes Accompanied by SO2 Insertion to Access Trifluoromethylated Cyclic N‐Sulfonylimines

“…In addition, the cyanamide moiety seemed to be pivotal to this electrolytic sequence, since electrochemical reaction between the N ‐arylacrylamide 9 with 2 a furnished the trifluoromethylated oxindole 11 instead of CF 3 ‐containing cyclic N ‐sulfonylimine 10 under the current electrolysis conditions [Eq. (2)] …”

Catalytic Electrosynthesis of N,O‐Heterocycles – Recent Advances

“…Zhang and co‐workers reported an interesting Mn‐catalyzed electrochemical strategy for trifluoromethylation/C(sp 2 )‐H functionalization (Scheme ). Employing manganese salts as the redox mediator and Langlois' reagent as a CF 3 source, a cascade of reactions led to a variety of trifluoromethyl‐substituted oxindoles 16 , indolines 17 , and isoquinoline‐1,3‐diones 18 in good yields.…”