Photochemical and electrochemical strategies in C–F bond activation and functionalization

Abstract

The activation and functionalization of C-F bonds under mild conditions can serve as an important tool for organic syntheses including the modification of pharmaceuticals or agrochemicals and the synthesis of...

Electrosynthetic C–F bond cleavage

“…10 ,15 Recent developments in radical synthesis have also delivered new methods for C–F bond cleavage, including photo- and electrochemical strategies. 16 The latter is becoming an increasingly popular synthetic approach, due to the prospects of new reactivity and selectivity, as well as resource friendly synthesis that follows with electricity as terminal reagent. 17 While excellent reviews summarizing the principles of and synthetic possibilities for electrosynthesis have been published lately, 18 a comprehensive overview of electrochemical protocols for C–F bond cleavage is missing in the literature to date.…”

Recent Advances in C–F Bond Activation of Acyl Fluorides Directed toward Catalytic Transformation by Transition Metals, N-Heterocyclic Carbenes, or Phosphines

“…The former facilitate the formation of [M]–allyl complexes catalyzed by transition metals (e.g., palladium) via ring-opening and C–F bond cleavage, 6 while the latter can undergo single-electron transfer (SET) in photoredox or electrochemical catalytic systems to produce fluoroalkyl radicals. 7 Nevertheless, the types of C–F bonds that can be effectively activated are still relatively limited. Therefore, chemists need to constantly develop new methods of activating C–F bonds while seeking ways to activate classical C–F bonds.…”

Chemodivergent Csp 3 ─F bond functionalization and cross-electrophile alkyl-alkyl coupling with alkyl fluorides

“…Csp 3 ─F bond functionalization has been achieved, for example, with reactive Lewis acids or via hydrogen bond assistance, and used for carbon-heteroatom bond formation (12)(13)(14), carbon-carbon coupling (15)(16)(17)(18)(19)(20), and halide exchange (21)(22)(23). With the exception of allylic, propargylic, and benzylic fluorides (24)(25)(26)(27)(28)(29)(30), low functional group compatibility, limited synthetic utility and competing rearrangement, elimination, or other side reactions, particularly when harsh reaction conditions need to be applied, have remained persistent problems despite some recently reported remarkable advances (31)(32)(33)(34)(35)(36)(37). Moreover, monofluoroalkyl C─F abstraction methods reported to date typically preserve the electrophilic reactivity of the carbon atom and are therefore largely limited to transformations with nucleophiles.…”