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

Solvent-dependent chemoselective synthesis of different isoquinolinones mediated by the hypervalent iodine(III) reagent PISA

• Ze-Nan Hu,
• Yan-Hui Wang,
• Jia-Bing Wu,
• Ze Chen,
• Dou Hong and
• Chi Zhang

Beilstein J. Org. Chem. 2024, 20, 1914–1921, doi:10.3762/bjoc.20.167

• radical clock experiment was carried out with 1d under the optimal reaction conditions, resulting in the formation of 2d in 54% yield, and no cyclopropyl ring opening products were observed. This result suggested that no radical intermediates were generated during the reaction (Scheme 5). According to the

• HFIP (3.0 mL) at room temperature. Isolated yield is stated. aThe yield of 2k was 56%. bThe yield of 2m was 24%. cThe yield of 2n was 11%. Control experiment to test for radical intermediates. Proposed mechanism for the reaction between 1a and PISA in anhydrous acetonitrile. Two other resonance

Novel oxidative routes to N-arylpyridoindazolium salts

• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2024, 20, 1906–1913, doi:10.3762/bjoc.20.166

• oxidation of both N-centers was demonstrated in [19]. The wide variety of the subsequent reaction channels for the radical cations formed under chemical or electrochemical oxidation of diarylamines, as well as availability of variously substituted diarylamines make them perspective starting compounds for

• amount (5%) of the N,N’-diaryldihydrophenazine radical cation that is the byproduct corresponding to the intermolecular oxidative C–N coupling of the diarylamine A1 was detected in the reaction mixture. This emphasizes that the both processes are of the same nature and proceed through the same

• intermediate (i.e., the diarylamines’ radical cation) and indicates the dominance of the intramolecular cyclization over the intermolecular C–N coupling process. Oxidation of diarylamines in the presence of an excess of trifluoroacetic acid gave no targeted pyridoindazolium salts, whereas the amount of

Electrochemical radical cation aza-Wacker cyclizations

• Sota Adachi and
• Yohei Okada

Beilstein J. Org. Chem. 2024, 20, 1900–1905, doi:10.3762/bjoc.20.165

• Sota Adachi Yohei Okada Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan 10.3762/bjoc.20.165 Abstract Electrochemical or photochemical single-electron oxidation of bench-stable substrates can generate radical

• cations that offer unique reactivities as intermediates in various bond-formation processes. Such intermediates can potentially take part in both radical and ionic bond formation; however, the mechanisms involved are complicated and not fully understood. Herein, we report electrochemical radical cation

• aza-Wacker cyclizations under acidic conditions, which are expected to proceed via radical cations generated by single-electron oxidation of alkenes. Keywords: alkene; aza-Wacker cyclization; electrochemistry; radical cation; sulfonamide; Introduction Activating bench-stable substrates is the first

Synthesis of polycyclic aromatic quinones by continuous flow electrochemical oxidation: anodic methoxylation of polycyclic aromatic phenols (PAPs)

• Hiwot M. Tiruye,
• Solon Economopoulos and
• Kåre B. Jørgensen

Beilstein J. Org. Chem. 2024, 20, 1746–1757, doi:10.3762/bjoc.20.153

• radical (potassium nitrosodisulfonate) [13] or catalytic systems like methyltrioxorhenium(VII) (MeReO3) [14] and 2-iodobenzenesulfonic acids (IBS)/Oxone® [15] led to either p-quinones or o-quinones, depending on the substituents in the para-position to the hydroxy group. Recently, hypervalent iodine

• dimers, which indicates a radical intermediate [36]. Swenton and co-workers [37] established evidence for the phenoxonium ion (Scheme 1), and were further able to divert the reaction into forming ortho-oxidation due to steric hindrance (Scheme 2). Cyclic voltammetry studies of the oxidation of 2-naphthol

• chrysenols nor phenanthrols, suggesting a chemically irreversible reaction of the radical cation intermediate with the ensuing product no longer being electrochemically active within the potential window of the CV scans. However, a reduction peak was observed for compound 1b (see Figure S2 in Supporting

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• yields (82–85%) (Scheme 28). The authors proposed a free radical mechanism facilitated by hydrogen peroxide, generating a primary radical at the terminal nitrogen atom -CO-HN• which then adds to the carbon atom of the imino group. The reaction mechanism was substantiated by theoretical calculations

• . According to the mechanism, the heterocyclic ring closes by the attack of the bulky radical -CO-HN• over the α steroidal side to circumvent the 1,3-diaxial interaction with the methyl group at C-10. Spiro-1,3,4-oxadiazoline steroid Shamsuzzaman et al. achieved the synthesis of 5’-acetamido-3’-acetyl-(3R

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations

• Ryo Tanifuji and
• Hiroki Oguri

Beilstein J. Org. Chem. 2024, 20, 1693–1712, doi:10.3762/bjoc.20.151

• toward developing a chemo-enzymatic synthetic process. Presumably, the reactive iron(IV)-oxo species in dioxygenase BscD abstracts an allylic hydrogen at C1 and generates intermediate A. Subsequent α-face-selective hydroxylation of the resulting allylic radical at the C3 position would yield brassicicene

• ]. The P450 enzyme BscF is responsible for regioselective abstraction of a hydrogen at C12 and subsequent diastereoselective hydroxylation of the radical intermediate B to produce brassicicene B (10). Meanwhile, further single-electron oxidation of the intermediate B would trigger a Wagner–Meerwein-type

Ring opening of photogenerated azetidinols as a strategy for the synthesis of aminodioxolanes

• Henning Maag,
• Daniel J. Lemcke and
• Johannes M. Wahl

Beilstein J. Org. Chem. 2024, 20, 1671–1676, doi:10.3762/bjoc.20.148

• the 54% and 63% yield, respectively (Table 1, entries 3 and 4). We observed an increase in Norrish II fragmentation in these cases. The observed diastereoselectivity was poor, supporting the radical character of the ring-closing event. A similar trend was observed when studying the methanesulfonyl (Ms

Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

• Maria-Paula Schröder,
• Isabel P.-M. Pfeiffer and
• Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

• (Mg2+-dependent, metal-independent, cobalamin-dependent), common structural folds (class I–V, with class I being the largest group, characterised by the Rossmann fold) [58], or catalytic mechanism (SN2 mechanism, radical mechanism, Figure 3) [59]. This review categorises RiPP MTs based on the acceptor

• atom, describing O-, N-, C-, and S-MTs; halide MTs have not (yet) been identified in RiPP pathways. The enzymes described below are either conventional SAM-dependent MTs or radical SAM (rSAM) MTs; rSAM MTs are one subfamily of the large rSAM enzyme superfamily, which encompasses enzymes catalysing a

• involved in RiPP maturation, all C-MTs described in the following section are classified as rSAM C-MTs. Radical SAM C-methyltransferases Radical SAM enzymes typically contain a conserved CxxxCxxC motif. The cysteine residues of this motif coordinate a [4Fe-4S] cluster. rSAM MTs can be classified based on

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• radicals and ions imparted through delocalisation with the adjacent π-system [13][14][15]. In general, the more stabilised the benzylic radical, the weaker the C(sp3)–H bond, as demonstrated when considering the BDEs of a series of phenyl-substituted methanes (Figure 1B). The changes in BDE correlate with

• mechanistic strategies, namely, electrophilic, radical and nucleophilic approaches, and highlighted when emerging technologies, such as photo- and electrochemistry effect the desired transformation [22][27]. Review Electrophilic benzylic C(sp3)–H fluorination Base mediated Electrophilic fluorinating reagents

• excess NFSI, the heterobenzyl fluoride is obtained. In the case of product 3, the authors suggested that the absence of radical clock rearrangement products supported a polar mechanism. Conveniently, when both benzylic and heterobenzylic C–H bonds were present in a substrate, the reaction was selective

Tetrabutylammonium iodide-catalyzed oxidative α-azidation of β-ketocarbonyl compounds using sodium azide

• Christopher Mairhofer,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1510–1517, doi:10.3762/bjoc.20.135

• insights we also carried out our standard reaction (Table 1, entry 14) in the presence of well-established radical traps like TEMPO, di-tert-butylhydroxytoluene (BHT), or 1,1-diphenylethene (DPE). In neither case any influence on the yield was observed, thus ruling out a mechanism involving radical species

Electrophotochemical metal-catalyzed synthesis of alkylnitriles from simple aliphatic carboxylic acids

• Yukang Wang,
• Yan Yao and
• Niankai Fu

Beilstein J. Org. Chem. 2024, 20, 1497–1503, doi:10.3762/bjoc.20.133

• synthesis; electrophotocatalysis; radical decarboxylation; Introduction Alkylnitriles and their derivatives are widely found in pharmaceuticals and biologically active compounds [1][2][3]. In addition, within the field of synthetic organic chemistry, nitriles are synthetically useful handles that can be

• different types of aliphatic acids including primary ones could be successfully employed (Figure 1B, reaction 1). The groups of Waser [23] and Gonzalez-Gomez [24] reported the direct conversion of aliphatic acids to the corresponding alkylnitriles by merging photoredox catalysis and radical cyanation

• have provided innovative strategies, substrates in all of these reaction systems are generally limited to benzylic, α-amino-, and α-oxy aliphatic acids, presumably due to the necessity of stabilized radical intermediates for the following radical cyanation step. We and others have recently demonstrated

Synthesis of 4-functionalized pyrazoles via oxidative thio- or selenocyanation mediated by PhICl₂ and NH₄SCN/KSeCN

• Jialiang Wu,
• Haofeng Shi,
• Xuemin Li,
• Jiaxin He,
• Chen Zhang,
• Fengxia Sun and
• Yunfei Du

Beilstein J. Org. Chem. 2024, 20, 1453–1461, doi:10.3762/bjoc.20.128

• ][44][45]. However, the electrophilic thiocyanation of biologically important pyrazoles has been less explored [46][47][48]. Among them, the majority of the reported methods proceed through a radical pathway, with the SCN radical generated by the reaction of the thiocyanate source with a corresponding