Use of Task-Specific Ionic Liquid for Selective Electrocatalytic Fluorination

Abstract

Highly selective indirect anodic fluorination of organic compounds was successfully carried out for the first time by using a task-specific ionic liquid of iodoarene as a mediator in ionic liquid hydrogen fluoride salts.

Elektrifizierung der organischen Synthese

“…Interestingly,a nisole-derived iodoarenes performed best (Scheme 3). [25,26] Task-specific iodoarenes,carrying,for example,animidazolium moiety, [27] and polymer-supported iodoarenes [28] have also been developed. These are stable during the electrochemical reaction and product extraction, and can be reused in subsequent runs.T hese developments culminated in ahighly selective method for the electrochemical fluorination of (hetero)aromatic compounds under mild reaction conditions.…”

Fluoro-Pummerer rearrangement and analogous reactions

“…To avoid passivation of the anode, Fuchigami et al developed an indirect electrochemical fluorination system, employing a task-specific ionic liquid with an iodoarene moiety as the mediator in HF reagents and improved the reaction efficiency for a variety of electrochemical fluorinations [85]. A polymersupported iodobenzene (PSIB) mediator was also effective for indirect anodic fluorination of 53 in HF reagents such as Et 3 NÁ3HF [86] (Scheme 27).…”

“…The initial reaction of p-nitrophenyl undecyl sulfide (85) with NIS and Olah's reagent (PyÁ9HF) was not selective and gave mixtures of di-and trifluoro sulfides 86 and 87 and a geminal difluoroalkane 88 depending on the molar ratio of substrate and reagents (Table 2). In addition, the a-iodonated sulfide 89 and the fluorine free sulfoxide 90 were identified in the crude product mixture.…”

Cyclohexane-Based Liquid-Biphasic Systems for Organic Electrochemistry

“…3) Although electrodes can be rapidly removed from the reaction mixtures after the completion of electrochemical transformations, the separation of products from supporting electrolytes that are necessary for imparting electrical conductivity to polar organic solvents is still required. In order to address this problem, various ingeniously designed electrochemical reaction systems have been developed [32][33][34][35][36]. In this chapter, we describe cyclohexane-based liquid-biphasic systems as unique separation techniques that are well-combined with organic electrochemistry.…”