Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• . Electricity can perform the oxidation and reduction process by exchanging electrons on the electrode surface in a region called the double layer (DL) [12]. Unlike traditional methods that require high temperature, pressure, and external oxidants, electrochemistry is an efficient and energy-saving approach

• electron-withdrawing groups. In 2024, Wang et al. [62] reported an electrochemical method for the synthesis of phosphorylated indoles in the presence of Cp2Fe as the mediator under mild reaction conditions without the need for external oxidants. This method improves the scalability of the resulting

• corresponding thiophosphorylated product (Scheme 27). Recently, a novel and one-pot electrochemical oxidation method was reported for synthesizing S-(hetero)aryl phosphorothioates without using any oxidants or transition metals at room temperature [68]. The reaction was carried out in an undivided cell. The

Synthesis of disulfides and 3-sulfenylchromones from sodium sulfinates catalyzed by TBAI

• Zhenlei Zhang,
• Ying Wang,
• Xingxing Pan,
• Manqi Zhang,
• Wei Zhao,
• Meng Li and
• Hao Zhang

Beilstein J. Org. Chem. 2025, 21, 253–261, doi:10.3762/bjoc.21.17

• [48][49]. However, some of the previously reported methods have limitations such as the use of strong oxidants, expensive reagents/catalysts, and lengthy work-up procedures, so there is still a need for simpler and more environmentally friendly methods for the preparation of 3-sulfenylchromones. In

Recent advances in electrochemical copper catalysis for modern organic synthesis

• Yemin Kim and
• Won Jun Jang

Beilstein J. Org. Chem. 2025, 21, 155–178, doi:10.3762/bjoc.21.9

• toxic chemical oxidants and releasing hydrogen gas as the sole byproduct. Various benzamides 1 and terminal arylalkynes 2 bearing electron-rich or electron-withdrawing groups provided the desired products 3 with high chemoselectivities. However, terminal alkynes with alkyl substituents did not yield the

• % CuCl2 catalyst was required, and anodic oxidation was employed instead of stoichiometric chemical oxidants. This cascade strategy is compatible with various substituted N-arylenamines 57 that bear electron-withdrawing and electron-donating groups, facilitating the production of quinoxaline scaffolds 59

• performed using electrophilic chlorinating reagents or stable and readily available chloride sources with stoichiometric amounts of chemical oxidants. However, in this catalytic system, chloride (Cl−) from HCl was used as the chlorinating agent, and electrophilic chlorine (Cl+) was generated in situ by the

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

Hypervalent iodine-mediated intramolecular alkene halocyclisation

• Charu Bansal,
• Oliver Ruggles,
• Albert C. Rowett and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

• structures. HVI reagents are characterized by their diverse reactivity as oxidants and electrophilic reagents. In addition, they are inexpensive, non-toxic and considered to be environmentally friendly. An important application of HVI reagents is the synthesis of halogenated cyclic compounds, in particular

• then forms the product. Kitamura and co-workers additionally reported a synthesis of 3-fluoropyrrolidines 14 in 2017 using an alternative source of fluoride (Scheme 8) [33]. The authors used either PhI(OAc)2 or PhI(OCOCF3)2 as oxidants and pyridine·HF as a source of fluoride. This alternative reagent

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

• peroxides, oxaziridines, and their derived species are often applied as terminal oxidants [7][8]. The weakness of the O–O bond allows alkoxy radicals to form through homolysis or reduction [9]. The generated alkoxy radicals provide an accessible tool for selective radical cascades, where a variety of

Structure and thermal stability of phosphorus-iodonium ylids

• Andrew Greener,
• Stephen P. Argent,
• Coby J. Clarke and
• Miriam L. O’Duill

Beilstein J. Org. Chem. 2024, 20, 2931–2939, doi:10.3762/bjoc.20.245

• synthetic organic chemistry, becoming indispensable tools in total synthesis, late-stage functionalisation and radiolabelling [1][2][3][4][5][6][7][8][9]. Due to their great mechanistic flexibility, including reactivity as oxidants, electrophiles, radical precursors and transmetalating agents, they often

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

• arylation; rearrangement reaction; Introduction The chemistry of hypervalent iodine compounds is well-established and they are prevalent as oxidants and electrophilic reagents in organic conversions [1][2][3]. They have gained significant attention due to their high reactivity and ability to carry out

• in aryl-transfer processes, DIAS are frequently employed as photoinitiators for cationic polymerizations [31][32][33], Lewis acids [34], oxidants [35][36] and in the field of macromolecular chemistry [37][38]. Additionally, biological activity is also exhibited by iodonium salts, often due to their

• or without the use of transition metals [44]. Thus, they address both the financial and environmental challenges associated with organic synthesis by acting as environmentally benign substitutes for costly organometallic catalysts and heavy-metal-based oxidants. Diaryl iodide salts consist of two

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

• cyclization of aryl hydrazones with aryl isothiocyanates promoted by elemental sulfur [70]. In the course of their studies for the thiocyanation of ketene dithioacetals, Yang, Wang and co-workers developed an electrochemical oxidization-based synthetic strategy to circumvent the need for external oxidants. In

• this context, a unique example of the thiocyanation of a hydrazone was depicted [71]. A key feature of the approach is to circumvent the need for external oxidants. In the same vein, the group of Hajra [72] and Yang [73], independently, investigated the electrochemical C–H sulfonylation of a library of

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

• -hydroxy-6-methyluracil, etc.). One of the successful methods for hydroxylation is peroxydisulfate oxidation. By modifying the Elbs reaction through catalysis and the introduction of additional oxidants, we have been able to significantly increase the yields of practically useful compounds. Keywords

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

• oxidants or reductants, offer unprecedented control of reactions through the continuous variation of the applied potential and the possibility of combination with photochemical processes. This capability is a substantial advantage for performing electrochemical or photoelectrochemical LSF. Ultimately

• gaining increasing interest in both academia and industry due to its numerous advantages and potential applications [1][2]. Electrochemical methods can reduce costs and waste generation by eliminating the need for chemical oxidants or reductants, and they can be safely and easily scaled up in flow

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

• -prefunctionalized materials in order to proceed with the rearrangement. However, the Achmatowicz reaction or similar methodologies involve a catalytic to stoichiometric amount of oxidants such as m-CPBA [7], PCC [8], Br2 [9], NBS [10], DMDO [11], KBr/Oxone [12], Na2S2O8 [13], photosensitizers/O21 [14], or Me2S [15

• File 1, Table S1, entries 4–6) however, when the time was increased there was minimal enhancement in yield (see details in Supporting Information File 1, Table S1, entry 2). Following additional adjustment of the reaction conditions with various solvents, oxidants, lights, and photocatalysts, (see

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

• photocatalysts (PC) that act as oxidants in the excited state [27]. The direct functionalization of amides with alkenes has been a relatively underexplored area in research, as evidenced by the limited number of examples reported in the literature. An interesting observation was made by the Nicewicz group during

Hypervalent iodine-mediated cyclization of bishomoallylamides to prolinols

• Smaher E. Butt,
• Konrad Kepski,
• Jean-Marc Sotiropoulos and
• Wesley J. Moran

Beilstein J. Org. Chem. 2024, 20, 2455–2460, doi:10.3762/bjoc.20.209

• entry 2). The cyclization of amide 3a did not occur in the absence of an iodine source. Other oxidants, solvents, and acids were screened but superior conditions were not discovered. With the optimized conditions in hand, the scope of the cyclization was investigated (Scheme 3). We examined the

Deuterated reagents in multicomponent reactions to afford deuterium-labeled products

• Kevin Schofield,
• Shayna Maddern,
• Yueteng Zhang,
• Grace E. Mastin,
• Rachel Knight,
• Wei Wang,
• James Galligan and
• Christopher Hulme

Beilstein J. Org. Chem. 2024, 20, 2270–2279, doi:10.3762/bjoc.20.195

• flexibility [8]. Indeed, early incorporation of deuterium during hit generation may negate the need for late-stage C–H functionalization which often requires strong external oxidants or affords products with significantly lower biological activity [25][26][27]. Thus, eight MCRs were evaluated for D-reagent

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

• ]. 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

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

• Na2SO4 (Table 1, entries 3 and 4). Next, different commercially available iodanes were employed as oxidants, such as PIDA, phenyliodine(III) bis(trifluoroacetate) (PIFA), N-tosyliminobenzyliodinane (PhINTs), iodosylbenzene (PhIO), and Koser’s reagent (HTIB) (Table 1, entries 5–9). Of the reagents tested

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

• active ones by DNA sequencing. Great challenges, however, characterize the synthetic methodologies, since the chemistry must display a broad scope, be compatible with water and operationally simple, and preserve the genetic information (i.e., no harsh conditions, strongly acidic pHs, no oxidants or Lewis

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

• making them less desirable for industrial scale [19]. Electrochemical synthesis methods have a huge potential and this field is currently undergoing a renaissance [20][21][22][23][24]. Replacing chemical oxidants with electric current reduces waste production and gives a sustainable and inherently safe

• cations B and C which have only one Clar sextet with two alternative positions. Conclusion The electrochemical oxidation of polycyclic aromatic phenols to quinones represents a green alternative to chemical oxidants. Hydrogen gas evolution can be handled by recycling of the reaction mixture through the

Oxidation of benzylic alcohols to carbonyls using N-heterocyclic stabilized λ³-iodanes

• Thomas J. Kuczmera,
• Pim Puylaert and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 1677–1683, doi:10.3762/bjoc.20.149

• oxidants in combination with transition-metal catalysts. Metal-free methods employ chlorodimethylsulfonium compounds as the reactive species and have gained great popularity under the name Swern oxidation or the Corey–Kim oxidation [11]. Hypervalent iodine compounds have also been studied and are well

• established in several oxidative transformations including the synthesis of complex molecules and drugs [12][13]. The most prominent examples are the pentavalent derivatives 2-iodoxybenzoic acid (IBX) and Dess–Martin periodinane (DMP) [14][15]. Although mild and selective oxidants, these highly oxidized λ5

• iodanes (NHIs) as effective λ3-iodane oxidants for the selective synthesis of ketones and aldehydes, avoiding overoxidation to carboxylic acids. The developed protocols proved particularly effective for benzylic alcohols, yielding good to excellent results. The beneficial role of chloride salt additives

Divergent role of PIDA and PIFA in the AlX₃ (X = Cl, Br) halogenation of 2-naphthol: a mechanistic study

• Kevin A. Juárez-Ornelas,
• Manuel Solís-Hernández,
• Pedro Navarro-Santos,
• J. Oscar C. Jiménez-Halla and
• César R. Solorio-Alvarado

Beilstein J. Org. Chem. 2024, 20, 1580–1589, doi:10.3762/bjoc.20.141

• halogenation via PhIX2. Keywords: aromatic bromination; aromatic chlorination; density functional theory (DFT); hypervalent iodine; iodine(III); Introduction Hypervalent iodine(III) reagents have gained attention as strong oxidants with a low toxicity [1][2][3][4][5][6][7][8] and due to the ability to mimic

• protocol for the electrophilic bromination of arenes, mainly phenols [28][29]. Accordingly, the bromination reaction was initially explored by mixing PIFA and AlBr3, which gave an acceptable yield (84%). However, other iodine(III) reagents were tested as oxidants during the optimization process. Thus, when

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

• easily available and cheapest nucleophilic N3 source (for other remarkable approaches using alternative catalysts and oxidants see references [24][25][26]). In addition to the racemic approach, they also showed that this reaction can be rendered enantioselective by using advanced Maruoka-type quaternary

• of the tert-butyl-containing β-ketoester 1a (Table 1 gives an overview of the most significant results obtained hereby). First experiments testing different oxidants in combination with Bu4NI (30 mol %) in 1,2-dichloroethane (DCE), a solvent that we found to be well-suited for oxidative α

• -heterofunctionalizations before [39], showed that DBPO clearly outperforms all the other oxidants tested under these conditions (Table 1, entries 1–5). While H2O2 gave 2a in low yield only (Table 1, entry 1), the use of mCPBA (Table 1, entry 3) and t-BuOOH (Table 1, entry 4) mainly resulted in the formation of the α-OH

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

• converts a diverse range of aliphatic carboxylic acids including primary and tertiary alkyl acids into synthetically versatile alkylnitriles without using chemical oxidants or costly cyanating reagents under mild reaction conditions. Keywords: aliphatic carboxylic acids; alkylnitriles; electroorganic

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

• NH4SCN (Table 1, entries 4–6). Next, other oxidants including phenyliodine(III) diacetate (PIDA), phenyliodine(III) bis(trifluoroacetate) (PIFA), iodosobenzene (PhIO), and NCS were applied, and the results indicated that PhICl2 was the most effective oxidant (Table 1, entries 7–10). Later on, when the

Hypervalent iodine-catalyzed amide and alkene coupling enabled by lithium salt activation

• Akanksha Chhikara,
• Fan Wu,
• Navdeep Kaur,
• Prabagar Baskaran,
• Alex M. Nguyen,
• Zhichang Yin,
• Anthony H. Pham and
• Wei Li

Beilstein J. Org. Chem. 2024, 20, 1405–1411, doi:10.3762/bjoc.20.122

• catalysis, which often involves the catalytic use of an iodoarene with stoichiometric oxidants such as MCPBA, Selectfluor, etc. [18][19][20]. Earlier and recent hypervalent iodine-catalyzed olefin halofunctionalizations by several groups have predicated on the use of intramolecular olefin substrates