Pyridinium-Masked Enol as a Precursor for Constructing Alpha-Fluoromethyl Ketones

We present herein a pyridinium-masked enol as a versatile platform to produce ketones bearing tri-, di-, and monofluoromethyl in the presence of [Ir(dF(Me)ppy)]2(dtbbpy)]PF6 under blue light (455 nm) irradiation. By simply changing the F-source, α-trifluoromethyl ketones, α-difluoromethyl ketones, and α-monofluoromethyl ketones could be easily prepared in moderate to excellent yields in one step, making it a practical tool for the synthesis of fluorine-containing ketones. In addition, the pyridinium-masked enol could also be extended to the synthesis of sulfonyl ketones. The findings of the present protocol contribute to the arsenal of fluorine chemistry and might have potential applications in the pharmaceutical and agrochemical industries.

Electrochemical cyclization of N-cyanamide alkenes with CF3SO2Na to access C,N-(bis)trifluoromethylated cyclic amidines and related compounds

An electrochemical trifluoromethylative cyclization of N-cyanamide alkenes and alkynes is presented, which afforded (bis)-C,N-trifluoromethylated cyclic amidines, azines and amides with selective multiple bond formations in a controllable manner.

Electrochemical Oxo-Fluorosulfonylation of Alkynes under Air: Facile Access to β-Keto Sulfonyl Fluorides

Radical fluorosulfonylation is emerging as an appealing approach for the synthesis of sulfonyl fluorides, which have widespread applications in many fields, in particular in the context of chemical biology and drug development. Here, we report the first investigation of FSO₂ radical generation under electrochemical conditions, and the establishment of a new and facile approach for the synthesis of β-keto sulfonyl fluorides via oxo-fluorosulfonylation of alkynes with sulfuryl chlorofluoride as the radical precursor and air as the oxidant. This electrochemical protocol is amenable to access two different products (β-keto sulfonyl fluorides or α-chloro-β-keto sulfonyl fluorides) with the same reactants. The β-keto sulfonyl fluoride products can be utilized as useful building blocks in the synthesis of various derivatives and heterocycles, including the first synthesis of an oxathiazole dioxide compound. Furthermore, some β-keto sulfonyl fluorides and derivatives exhibited notably potent activities against Bursaphelenchus xylophilus and Colletotrichum gloeosporioides.

Electrochemical Installation of CFH2 -, CF2 H-, CF3 -, and Perfluoroalkyl Groups into Small Organic Molecules

Electrosynthesis can be considered a powerful and sustainable methodology for the synthesis of small organic molecules. Due to its intrinsic ability to generate highly reactive species under mild conditions by anodic oxidation or cathodic reduction, electrosynthesis is particularly interesting for otherwise challenging transformations. One such challenge is the installation of fluorinated alkyl groups, which has gained significant attention in medicinal chemistry and material science due to their unique physicochemical features. Unsurprisingly, several electrochemical fluoroalkylation methods have been established. In this review, we survey recent developments and established methods in the field of electrochemical mono-, di-, and trifluoromethylation, and perfluoroalkylation of small organic molecules.

Electrochemical Synthesis of Fluorinated Ketones from Enol Acetates and Sodium Perfluoroalkyl Sulfinates

The electrochemical synthesis of fluorinated ketones from enol acetates and R_fSO₂Na in an undivided cell under constant current conditions was developed. The electrosynthesis proceeded via perfluoroalkyl radical generation from sodium perfluoroalkyl sulfinate followed by addition to the enol acetate and transformation of the resulting C radical to a fluorinated ketone. The method is applicable to a wide range of enol acetates and results in the desired products in yields of 20 to 85%.

Electrochemical Generation and Use in Organic Synthesis of C-, O-, and N-Centered Radicals

During the last decade several research groups have been developing electrochemical procedures to access highly functionalized organic molecules. Among the most exciting advances, the possibility of using free radical chemistry has attracted the attention of the most important synthetic groups. Nowadays, electrochemical strategies based on these species with a synthetic purpose are published continuously in scientific journals, increasing the alternatives for the synthetic organic chemistry laboratories. Free radicals can be obtained in organic electrochemical reactions; thus, this review reassembles the last decade's (2010-2020) efforts of the electrosynthetic community to generate and take advantage of the C-, O-, and N-centered radicals' reactivity. The electrochemical reactions that occur, as well as the proposed mechanism, are discussed, trying to give clear information about the used conditions and reactivity of these reactive intermediate species.

Recent advances in electrochemically driven radical fluorination and fluoroalkylation

Electrochemical fluorination (ECF) refers to the introduction of fluorine-containing moieties into organic molecules under electrochemical conditions.

Cross coupling of sulfonyl radicals with silver-based carbenes: a simple approach to β-carbonyl arylsulfones

A radical–carbene coupling reaction of sulfonyl radicals and silver-based carbenes has been well established, which provides an efficient approach to various β-carbonyl arylsulfones.

Electrochemical Minisci-type trifluoromethylation of electron-deficient heterocycles mediated by bromide ions

An electrochemical methodology for the Minisci-type trifluoromethylation of electron-deficient heterocycles mediated by cheap and easily available bromide ions has been developed.