Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• capability to function as radical initiators. The use of diaryliodonium salts as efficient electrophilic arylating reagents in a wide range of organic transformations is due to their unique features such as solid-state nature, excellent stability, and the presence of a robust leaving group [39][40][41][42

• the respective arylation product [50][51]. Lastly, arylation can occur through single-electron transfer (SET), where a cation radical obtained from aromatic hydrocarbons with high electron density yields the desired arylated product [52]. In this review article, we will provide a comprehensive

• mechanism by adding 2 equivalents of TEMPO to the reaction mixture. The absence of the desired product indicated the involvement of a radical pathway in the process. The proposed reaction mechanism begins with the activation of eosin Y by visible light from 5 W blue LEDs, transitioning it to its excited

C–H Trifluoromethylthiolation of aldehyde hydrazones

• Victor Levet,
• Balu Ramesh,
• Congyang Wang and
• Tatiana Besset

Beilstein J. Org. Chem. 2024, 20, 2883–2890, doi:10.3762/bjoc.20.242

• various transformations [54][55][56][57][58][59][60][61][62][63][64]. In consequence, a large number of transition-metal-catalyzed or radical-mediated processes for C–H functionalization of aldehyde hydrazones has flourished over the years. An ideal scenario for a direct and sustainable synthetic route

• insights into the transformation, additional experiments were conducted. First, the reaction was repeated in the presence of radical scavengers, namely 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) or di-tert-butylhydroxytoluene (BHT), and no significant impact on the outcome of the reaction was noticed

Copper-catalyzed yne-allylic substitutions: concept and recent developments

• Shuang Yang and
• Xinqiang Fang

Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232

• a moderate 40% yield, but impressively high enantiomeric excess of 83%. To further validate the mechanistic pathway of the reaction, the authors conducted both radical trapping experiments and controlled experiments. These investigations conclusively demonstrated that the reaction did not proceed

• via a radical mechanism and the presence of terminal alkynes was found to be crucial for the smooth progression of the reaction, which suggested that the reaction proceeded through the same copper vinyl allenylidene intermediate (Scheme 23). Yne-allylic substitutions through dearomatization and

• , they also achieved the construction of C–N axis chirality through remote substitution/cyclization/1,5-H shift process (Scheme 26). The control experiments confirmed that the reaction requires the joint participation of copper and terminal alkyne, and the radical-capture experiment also ruled out a

Interaction of a pyrene derivative with cationic [60]fullerene in phospholipid membranes and its effects on photodynamic actions

• Hayato Takagi,
• Çetin Çelik,
• Ryosuke Fukuda,
• Qi Guo,
• Tomohiro Higashino,
• Hiroshi Imahori,
• Yoko Yamakoshi and
• Tatsuya Murakami

Beilstein J. Org. Chem. 2024, 20, 2732–2738, doi:10.3762/bjoc.20.231

• safer control of Vm. Keywords: liposome; π–π interaction; reactive oxygen species; superoxide radical anion; Introduction The [60]fullerene (C60) is known as an excellent electron acceptor [1][2] and is commonly used in organic solar cell applications [3]. Taking advantage of the fact that C60 can be

• generation of ROS by catC60 in the absence or presence of PyBA. As spin trapping reagents for the singlet oxygen (1O2), hydroxyl radical (•OH) and superoxide radical anion (O2•–); 2,2,6,6,-tetramethyl-4-piperidone (4-oxo-TEMP), 3,4-dihydro-2,3-dimethyl-2H-pyrrole 1-oxide (DMPO), and 5-(diethoxyphosphoryl)-5

• as a •OH adduct of DMPO (DMPO-OH, Figure 5b(ii)) revealing that electron transfer reaction was also occurring. Using DEPMPO as a spin trapping reagent, detection of O2•– was tried and some radical adducts were detected, but without being clearly identified (Figure 5c(i), (ii)). The reason of the

Synthesis of spiroindolenines through a one-pot multistep process mediated by visible light

• Francesco Gambuti,
• Jacopo Pizzorno,
• Chiara Lambruschini,
• Renata Riva and
• Lisa Moni

Beilstein J. Org. Chem. 2024, 20, 2722–2731, doi:10.3762/bjoc.20.230

• Scheme 6. Based on the results reported by Zeitler [28], several mechanisms are involved in the oxidation of N-Ph-THIQ. The most probable involves the photoexcitation of the EDA (Electron Donor-Acceptor) complex promoting an electron transfer from N-Ph-THIQ to BrCCl3 to afford the amine radical cation

• and highly reactive BrCCl3 radical anion. Anyway, the N-Ph-THIQ can undergo numerous pathways towards the iminium ion 1a (see reference [28] for details). The oxidation of compound 2d may occur according to the same mechanism. However, alternative mechanisms, such as the direct hydride transfer from

Transition-metal-free decarbonylation–oxidation of 3-arylbenzofuran-2(3H)-ones: access to 2-hydroxybenzophenones

• Bhaskar B. Dhotare,
• Seema V. Kanojia,
• Chahna K. Sakhiya,
• Amey Wadawale and
• Dibakar Goswami

Beilstein J. Org. Chem. 2024, 20, 2655–2667, doi:10.3762/bjoc.20.223

• proceeded well only in solvents which can produce hydroperoxides in situ, we hypothesized that hydroperoxides have a pivotal role in the reaction mechanism. In order to confirm that the reaction proceeds through a radical mechanism, the decarbonylation–oxidation reaction of 3ba was performed in the presence

• of TEMPO, a known radical quencher [26]. To our expectations, the reaction did not proceed well in presence of TEMPO, giving a very poor yield of 4ba, confirming the role of radical in the reaction (Scheme 4). In addition, since it has been reported that the formation of hydroperoxides in THF is

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

• Alfiya R. Gimadieva,
• Yuliya Z. Khazimullina,
• Aigiza A. Gilimkhanova and
• Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

• useful. 5-Hydroxy-6-methyluracil (HMU) (Figure 1a) and 5-hydroxy-1,3,6-trimethyluracil (HTMU) (Figure 1b) have been identified as effective antioxidants and radical traps [5][6][7]. Additionally, 2-hydroxypyridine (HPy) has significant synthetic potential in the design of various bioactive compounds

• − ion, which is formed by the non-radical decomposition of the peroxydisulfate ion in a strongly alkaline medium [34]: The Elbs and Boyland–Sims reactions were also effectively modified by the use of H2O2 as a co-oxidant (binary oxidation mixture APS/H2O2). Adding 2.0–2.3 equiv of H2O2 (Table 3) [35

Transition-metal-free synthesis of arylboronates via thermal generation of aryl radicals from triarylbismuthines in air

• Yuki Yamamoto,
• Yuki Konakazawa,
• Kohsuke Fujiwara and
• Akiya Ogawa

Beilstein J. Org. Chem. 2024, 20, 2577–2584, doi:10.3762/bjoc.20.216

• , Sakai, Osaka 599-8531, Japan Organization for Research Promotion, Osaka Metropolitan University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan 10.3762/bjoc.20.216 Abstract A simple and versatile synthesis of arylboronates has been achieved by using triarylbismuthines as aryl radical sources

• the generation of aryl radicals, and the subsequent reaction with bis(pinacolato)diboron afforded a variety of arylboronates in moderate to good yields. Keywords: arylboronates; bis(pinacolato)diboron; radical reactions; transition-metal-free synthesis; triarylbismuthines; Introduction Arylboronates

• , the development of new synthetic methods of arylboronates using stable and versatile reagents under transition-metal-free conditions has recently attracted much attention [23][24][25][26][27]. In particular, the use of radical reactions has been considered as one of the effective methods, since

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

• -free electrochemical method. This route was reported in 2014 by the Baran and Blackmond groups [6]. A commercially available reagent, Zn(SO2CF3)2, was used as the CF3 radical source in the reaction. Additionally, a series of substrates could be difluoromethylated under the reported electrochemical

• conditions. A comparison was made between the developed electrochemical conditions for each substrate and an analogous non-electrochemical method using peroxide for CF3 radical generation. In all cases, the electrochemical route delivered improved yields (Scheme 1). The Wang group later discovered a C(sp2)–H

• anodic oxidation cleaves the diazene, resulting in the formation of an acyl radical and the release of molecular nitrogen. The subsequent step involves the decarboxylation of the acyl radical to produce an alkyl radical. This method was successfully applied to the late-stage functionalization of

Visible-light-mediated flow protocol for Achmatowicz rearrangement

• Joachyutharayalu Oja,
• Sanjeev Kumar and
• Srihari Pabbaraja

Beilstein J. Org. Chem. 2024, 20, 2493–2499, doi:10.3762/bjoc.20.213

• , [Ru(bpy)3]2+ undergoes transition to [Ru(bpy)3]2+* which is quenched by persulfate resulting in [Ru(bpy)3]3+ along with the simultaneous generation of sulfate and a sulfate radical. SET from furfuryl alcohol closes the catalytic cycle of the PC and an intermediate A is generated with L (L = SO4−· or

HFIP as a versatile solvent in resorcin[n]arene synthesis

• Hormoz Khosravi,
• Valeria Stevens and
• Raúl Hernández Sánchez

Beilstein J. Org. Chem. 2024, 20, 2469–2475, doi:10.3762/bjoc.20.211

• ]. In contrast, the protocol reported herein provides 94–98% yield when employing longer chain-containing aldehydes (1c–e). In addition to resorcinol, 2-methylresorcinol is commonly used in resorcin[n]arene synthesis as radical oxidation of the methyl unit in the ArCH3 fragments provides a benzyl

Photoredox-catalyzed intramolecular nucleophilic amidation of alkenes with β-lactams

• Valentina Giraldi,
• Giandomenico Magagnano,
• Daria Giacomini,
• Pier Giorgio Cozzi and
• Andrea Gualandi

Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210

• reactions limit the utility of this approach. Herein, we report an intramolecular photoredox cyclization of alkenes with β-lactams in the presence of an acridinium photocatalyst. The approach uses an intramolecular nucleophilic addition of the β-lactam nitrogen atom to the radical cation photogenerated in

• the linked alkene moiety, followed by hydrogen transfer from the hydrogen atom transfer (HAT) catalyst. This process was used to successfully prepare 2-alkylated clavam derivatives. Keywords: β-lactam; acridinium photocatalyst; alkenes; amides; intramolecular radical reaction; photoredox catalysis

• functionalization of amides with alkenes under photoredox conditions. Another viable approach for amide functionalization through photoredox catalysis involves the nucleophilic addition, in the presence of base, of an amide to a radical cation obtained by oxidation of an unfunctionalized alkene moiety (Figure 1A

Phenylseleno trifluoromethoxylation of alkenes

• Clément Delobel,
• Armen Panossian,
• Gilles Hanquet,
• Frédéric R. Leroux,
• Fabien Toulgoat and
• Thierry Billard

Beilstein J. Org. Chem. 2024, 20, 2434–2441, doi:10.3762/bjoc.20.207

• interests, no methods have been described to synthesize both trifluoromethoxylated and phenylselenylated molecules. The introduction of a CF3O moiety into organic molecules remains poorly described in the literature, especially the direct trifluoromethoxylation [44][45][46]. Only few radical

• of the oxidative conditions used (mCPBA [75], H2O2 [75], selectfluor®/H2O [76], SO2Cl2/NaHCO3 (aq) [77][78]), in most cases a complex mixture was observed and no corresponding vinylic compound was detected by NMR. The phenylselenyl moiety could also undergo radical reduction to produce

• are difficult to synthesize by nucleophilic substitution, such as products 5a and 5b [68]. Conclusion In this work, an efficient phenylseleno trifluoromethoxylation of alkenes has been developed to readily obtain β-selenylated trifluoromethoxylated compounds. These compounds can also undergo radical

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

• Daria A. Burmistrova,
• Andrey Galustyan,
• Nadezhda P. Pomortseva,
• Kristina D. Pashaeva,
• Maxim V. Arsenyev,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202

• established for these compounds. The electrochemical behavior of the studied compounds is influenced by several factors: the nature of the heterocycle and its substituents, the presence of a sulfur atom in the catechol ring, or a thione group in the heterocyclic core. The radical scavenging activity and

• antioxidant properties were determined using the reaction with synthetic radicals, the cupric reducing antioxidant capacity assay, the inhibition process of superoxide radical anion formation by xanthine oxidase, and the process of lipid peroxidation of rat liver (Wistar) homogenates in vitro. Keywords

• neuroprotective, antihypoxic effects, act as antiparkinsonian agents [3][4][5], exhibit antitumor and antibacterial activity [6][7][8], possess antioxidant properties for regulating free radical processes [9][10][11]. The functionalization of polyphenolic compounds by introducing various substituents or

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• deracemisation of an unsaturated amine 144 was reported by Li Dang and Xin-Yuan Liu (Scheme 30) [45]. They used CF3-radical-induced remote CH-activation, combined with Brønsted acid-catalysed chiral hydrogen atom transfer (HAT). In this reaction, triphenylphosphine first mediated the addition of the CF3-radical

• generated from Togni’s reagent (145) to a double bond of the δ-alkenylamine, followed by intramolecular hydrogen atom transfer and a single-electron oxidation of the intermediate alkyl radical to form an imine that is then reduced by hydrogen donor 147 catalysed by CPA (R)-VAPOL (148). The

Hydrogen-bond activation enables aziridination of unactivated olefins with simple iminoiodinanes

• Phong Thai,
• Lauv Patel,
• Diyasha Manna and
• David C. Powers

Beilstein J. Org. Chem. 2024, 20, 2305–2312, doi:10.3762/bjoc.20.197

• fashion. The dissimilarity of the diastereomeric ratios from cis- and trans- starting materials indicates that the potential intermediate is too short lived for complete ablation of the starting material stereochemistry. Second, the aziridination of cyclopentene by PhINTs in the presence of a radical trap

• N-tert-butyl-α-phenylnitrone (PBN) afforded the aziridine product 3b in 60% NMR yield (Scheme 4d), suggesting a radical pathway was unlikely to be operative. An 1H NMR experiment was carried out to probe the speciation of 2a in HFIP, and we observed that 2a underwent reversible ligand exchange with

• product. Such a process would account for the simultaneous stereochemical scrambling observed and the lack of radical trapping noted. Conclusion In conclusion, we describe the activation of simple iminoiodinane reagents by fluorinated alcohols, such as HFIP. While most iminoiodinane reagents do not engage

Synthesis and reactivity of the di(9-anthryl)methyl radical

• Tomohiko Nishiuchi,
• Kazuma Takahashi,
• Yuta Makihara and
• Takashi Kubo

Beilstein J. Org. Chem. 2024, 20, 2254–2260, doi:10.3762/bjoc.20.193

• ), Osaka University, Osaka, Japan Spintronics Research Network Division, Institute for Open and Transdisciplinary Research Initiatives (SRN-OTRI), Osaka University, Osaka, Japan 10.3762/bjoc.20.193 Abstract The di(9-anthryl)methyl (DAntM) radical was synthesized and investigated to elucidate its optical

• , electrical properties, and reactivity. The generation of the DAntM radical was confirmed by its ESR spectrum, which showed two broad signals. The unpaired electron is primarily localized on the central sp2 carbon and slightly delocalized over the two anthryl moieties. Although the DAntM radical undergoes

• dimerization in solution, the radical still remains even at 190 K due to the bulky nature of the two anthryl groups. Interestingly, upon exposure to air, the purple color of the radical solution quickly fades to orange, resulting in decomposition to give 9-anthryl aldehyde and anthroxyl radical derivatives

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

• against cell line 293 (IC50: 15.5 µM) [164], showed hydroxyl radical scavenging activity (EC50: 68.3 µM) [163], and turned out to be active against 24 tested protein kinases with IC50 values ranging from 0.35 to 5.7 µg/mL [147]. Graphislactones A and B (21 and 22) were first isolated from the lichens

• -picrylhydrazyl radical (DPPH; IC50: 9.6 μM) and hydroxyl radicals (scavenging activity of 70% and 91% at 0.05 and 0.27 μg/mL, respectively) [169][176]. Furthermore, it turned out to be cytotoxic against SW1116 cells (IC50: 9.5 μg/mL) [168]. The trimethyl ether of 4-hydroxyalternariol was named ‘graphislactone H

• ), Bacillus cereus (MIC values of 8–32 μg/mL [187][193], and further bacteria [163]. It turned out to be active against Trypanosoma brucei rhodesiense and Leishmania donovani (IC50 values of 1.5, 7.1 μM, respectively) and further protozoa [159]. It furthermore showed some radical scavenging activities [163

Efficacy of radical reactions of isocyanides with heteroatom radicals in organic synthesis

• Akiya Ogawa and
• Yuki Yamamoto

Beilstein J. Org. Chem. 2024, 20, 2114–2128, doi:10.3762/bjoc.20.182

• radical; isocyanide; radical addition; radical cyclization; Introduction Carbon monoxide is a very important C1 resource in both synthetic and industrial chemistry and is not only capable of reacting with a variety of active species such as carbon cations, carbon anions, and carbon radicals (Figure 1

• ] because isocyanide is susceptible to multiple imidoylation [9][10][11], whereas carbon monoxide is less susceptible to multiple carbonylation. Therefore, precise control of the reaction is required for selective formation of the monoimidoylation product. Regarding the radical reaction of isocyanides, the

• reaction of carbon radicals with isocyanides generates imidoyl radicals as key active species [12], and addition and cyclization reactions using these radical species are useful in synthetic organic chemistry, especially multicomponent synthesis. If various functional groups can be appropriately attached

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• cross-coupling and radical chemistry, as well as providing versatile synthetic approaches to pyrazoles. This overview summarizes the most important MCR syntheses of pyrazoles based on ring-forming sequences in a flashlight fashion. Keywords: cycloaddition; cyclocondensation; multicomponent reaction

Understanding X-ray-induced isomerisation in photoswitchable surfactant assemblies

• Beatrice E. Jones,
• Camille Blayo,
• Jake L. Greenfield,
• Matthew J. Fuchter,
• Nathan Cowieson and
• Rachel C. Evans

Beilstein J. Org. Chem. 2024, 20, 2005–2015, doi:10.3762/bjoc.20.176

• azo bond (N=N), resulting in a decrease in the double bond character and a lowering of the energy barrier to isomerisation [37][38][39]. Additionally, Z–E isomerisation can be catalysed electrochemically in the presence of free electrons [40] or holes [27]. The wide variety of radical and charged

• stability of the Z isomer, AAP photoswitches are also susceptible to Z–E isomerisation on X-ray irradiation due to the presence of catalysing ionic and radical species from radiolysis of the surrounding water. This can be seen by a partial return of the UV–vis absorbance spectrum of AAPTAB from the Z to the

• the temperature change due to heating effects from the X-ray beam is <0.4 °C for a single 500 ms frame (see section 7, Supporting Information File 1), meaning that this will not affect the Z–E isomer ratio. The diverse range of reactive radical species formed in the radiolysis process must therefore

Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

• Aurélie Claraz

Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175

• hydrazones can act as radical acceptors for the synthesis of functionalized amines or hydrazones through reductive functionalization [21][25][26] or oxidative C(sp2)–H functionalization [27][28], respectively. Consequently, given their rich reactivity profile, exploring new synthetic transformations of

• hydrazones is of significant importance and can contribute to the formation of novel organic compounds. Electrosynthesis enables the generation of either radical, radical ionic or ionic species [29] under mild and environmentally friendly reaction conditions [30][31]. The direct use of electrical current to

• formation of dimeric side products. Cyclic voltammetry analysis suggested an initial anodic single electron transfer (SET) to radical cation 5, cyclization and deprotonation. Subsequent SET oxidation in solution by 5 led to cation 7. Final deprotonation furnished aromatic cycle 4. In 2022, Zhang et al

Development of a flow photochemical process for a π-Lewis acidic metal-catalyzed cyclization/radical addition sequence: in situ-generated 2-benzopyrylium as photoredox catalyst and reactive intermediate

• Masahiro Terada,
• Zen Iwasaki,
• Ryohei Yazaki,
• Shigenobu Umemiya and
• Jun Kikuchi

Beilstein J. Org. Chem. 2024, 20, 1973–1980, doi:10.3762/bjoc.20.173

• Abstract A flow photochemical reaction system for a π-Lewis acidic metal-catalyzed cyclization/radical addition sequence was developed, which utilizes in situ-generated 2-benzopyrylium intermediates as the photoredox catalyst and electrophilic substrates. The key 2-benzopyrylium intermediates were

• subsequent photochemical radical addition [46][47][48][49][50][51][52][53][54], which affords 1H-isochromene derivatives 3 through three catalytic cycles (Scheme 1a) [55]: catalytic cycles I and II and a photoredox cycle of the photocatalyst [56][57] (see Supporting Information File 1 for the overall

• , initiating further radical reactions through the formation of radical cations B. Nucleophilic arylmethyl radicals C, which are generated from radical cations B by desilylation, undergo an addition reaction with 2-benzopyrylium intermediates A, giving rise to the corresponding radical cation. Catalytic cycle

Radical reactivity of antiaromatic Ni(II) norcorroles with azo radical initiators

• Siham Asyiqin Shafie,
• Ryo Nozawa,
• Hideaki Takano and
• Hiroshi Shinokubo

Beilstein J. Org. Chem. 2024, 20, 1967–1972, doi:10.3762/bjoc.20.172

• radicals derived from azo radical initiators. The radical selectively attacked the distal α-position relative to the meso-position to construct a nonaromatic bowl-shaped structure. The photophysical and electrochemical properties of the obtained radical adducts were compared to those of the parent Ni(II

• ) norcorrole. The radical reactivity of Ni(II) norcorroles was investigated by density functional theory (DFT) calculations. Keywords: 16π; antiaromatic; norcorrole; porphyrinoid; radical; Introduction Considerable attention has been directed toward antiaromatic norcorroles [1][2][3] due to the fascinating

• ]. Moreover, the ring-expansion or ring-opening reactions of Ni(II) norcorroles are induced by an activated zwitterionic intermediate [22], oxidants [23][24], and carbenes [25][26]. During the last decade, the various reactivities of Ni(II) norcorroles have been elucidated. However, the reaction with radical

1,2-Difluoroethylene (HFO-1132): synthesis and chemistry

• Liubov V. Sokolenko,
• Taras M. Sokolenko and
• Yurii L. Yagupolskii

Beilstein J. Org. Chem. 2024, 20, 1955–1966, doi:10.3762/bjoc.20.171

• 1,2-difluoroethylene (HFO-1132). The major routes for the preparation of the E- and Z-isomer of HFO-1132 are reviewed, along with the chemistry in radical, nucleophilic, and electrophilic reactions. Keywords: 1,2-difluoroethylene; fluorinated monomers; HFO-1132; hydrofluoroolefins; radical reactions

• ]. In this electrophilic reaction, two products were formed in 3:1 ratio (Scheme 17) in a very low yield of 0.4%. In patent literature [95], radical reaction of 1,2-difluoroethylene with long-chain perfluoroalkyl iodides (CnF2n + 1I, n = 2–8) was described (Scheme 18). Products formed were further

• ], while S-nucleophiles, namely thiophenolates, led to products upon fluorine atom substitution, which were isolated in low yield. Corresponding disulfides were isolated as major products, even when the reaction was carried out under inert atmosphere, suggesting a radical process. In summary, we compiled