Synthesis of sterically shielded piperidine nitroxides via acid-catalyzed heterocyclization of β-aminoketone derivatives with ketones

• Mark M. Gulman,
• Yurii I. Glazachev and
• Sergey A. Dobrynin

Beilstein J. Org. Chem. 2026, 22, 948–954, doi:10.3762/bjoc.22.74

• use as catalysts for alcohol oxidation [8], electrode active materials in energy storage devices (batteries) [9], as well as antioxidants and superoxide dismutase (SOD) mimetics [10]. Their sterically shielded analogs, such as 2,2,6,6-tetraethylpiperidine-1-oxyl (TEEPO), were initially developed for

• ], followed by oxidation in the tungstate/hydrogen peroxide system [29]. It should be noted that no case of heterocyclization has ever been described where the resulting piperidine cycle contained three substituents at the 2- and 6-positions of the heterocycle. Subsequent treatment of these nitrones with

• alkynyl- or allylmagnesium halides gave 2-alkynyl or 2-allyl-substituted nitroxides. Finally, carbon–carbon multiple bonds were removed via Pd-catalyzed hydrogenation and the nitroxide group was recovered by mild oxidation. This approach was used to prepare both symmetric 2,2,6,6-tetraethyl- and 2,2,6,6

Recent advances in copper-catalyzed direct hydroamination of alkenes with (hetero)aromatic amines

• Hyejeong Lee and
• Yunmi Lee

Beilstein J. Org. Chem. 2026, 22, 925–947, doi:10.3762/bjoc.22.73

• methodology is demonstrated via a one-pot sequence consisting of copper-catalyzed aza-Michael addition followed by base-mediated cyclization and acid-promoted aerobic oxidation to afford quinolinone derivatives (Scheme 4) [38][39]. In this sequence, 2-aminobenzoate derivatives 4 reacted with α,β-unsaturated

• carbonyl compounds 5 to form the β-amino ketone intermediates, which subsequently underwent base-mediated intramolecular cyclization using KOt-Bu and air oxidation of the resulting 2,3-dihydro-4(1H)-quinolinone intermediates 7 in the presence of HCl to yield functionalized quinolin-4(1H)-one derivatives 6

• functionality generated a hemiaminal intermediate, which underwent Cu(I)-assisted air oxidation to produce the corresponding amide intermediate 27. Subsequent intramolecular aza-Michael addition of the pyridinyl nitrogen to the activated α,β-unsaturated ester led to cyclization, ultimately furnishing the

Site-specific labelling of native peptides and proteins: chemical and enzymatic strategies

• Antonio Angelastro,
• Jonathan Bargh,
• Subhajit Guria,
• Victor Laserna and
• Louis Luk

Beilstein J. Org. Chem. 2026, 22, 857–881, doi:10.3762/bjoc.22.67

• -like linkages (≈9 M−1 s−1; Scheme 1d) [10], whereas 2-formylphenylboronic acid 3 (FPBA) generates thiazolidino boronate with noticeably improved kinetics (103 M−1 s−1; Scheme 1e) [11][12]. Aldehydes can be introduced at protein N-termini through several strategies: oxidation of serine or threonine with

• splicing to generate a C-terminal thioester from recombinantly expressed proteins [20][21][22]. One distinctive feature of the C-terminal carboxylate is its lower oxidation potential compared to the side chains of aspartate or glutamate, making it more amenable to selective redox-based modifications. This

• oxidation state of phosphorous, diethynylphosphonites 12 also utilize conjugate addition to provide a versatile three-point conjugation platform [37]. Related technologies have been adapted to link multiple disulfide residues simultaneously. Using bis-dibromopyridazinediones bis-9 [38] or bis/tetra

The trans-influence in gold chemistry from a catalytic perspective

• Manfred Bochmann

Beilstein J. Org. Chem. 2026, 22, 838–856, doi:10.3762/bjoc.22.66

• . This effect is probably more dominant in gold chemistry than in most other transition-metal complexes; it can on occasions appear even more important than the formal oxidation state and d-electron count. Tilset and co-workers have recently summarised the importance of the trans-influence in C^N

Unsymmetrical sulfoxides with sterically hindered catechol fragment: synthesis, structure, electrochemical properties, and antiradical activity

• Daria A. Burmistrova,
• Vasiliy A. Fokin,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Maxim V. Arsenyev,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2026, 22, 828–837, doi:10.3762/bjoc.22.65

• 10.3762/bjoc.22.65 Abstract New unsymmetrical sulfoxides containing a redox-active sterically hindered catechol fragment and a nonpolar hydrocarbon substituent at the sulfoxide group were synthesized via the oxidation of the corresponding catechol thioethers with hydrogen peroxide. The yield of the

• compounds. The electrochemical behavior of sulfoxides was studied in comparison with that of the parent catechol thioethers. The redox transition corresponding to catechol fragment oxidation is shifted to the anodic region relative to the initial thioethers, which is attributed to the more electron

• ]. We have previously shown that hybrid molecules based on sterically hindered catechol thioethers, bearing various polar and hydrocarbon groups, exhibit pronounced chelating [15][16], antiradical, and cryoprotective activity [17][18][19][20]. The ability of the sulfur atom to exist in various oxidation

Total synthesis of the capsular polysaccharide repeating unit towards the development of a glycoconjugate vaccine against Klebsiella pneumoniae ST512

• Shuo Zhang,
• Ondřej Daněk and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2026, 22, 821–827, doi:10.3762/bjoc.22.64

• deprotection was achieved by removing the Fmoc and Lev protecting groups with sodium methoxide, followed by 2,2,6,6-tetramethyl-1-piperidinyl-1-oxyl (TEMPO)/bis(acetoxy)iodobenzene (BAIB)-mediated oxidation of the C6-primary alcohol [35]. Final hydrogenolysis furnished the target hexasaccharide repeating unit

Halogenated azobenzene acrylates: from efficient solution photoswitching to stable solid-state photochromic materials

• Martina Vachtlová,
• Michaela Fecková,
• Vítězslav Zima,
• Jan Podlesný,
• Milan Klikar,
• Oldřich Pytela,
• Patrik Pařík,
• Jakub Opršal,
• Eliška Juhaňáková,
• Veronika Chrtová and
• Filip Bureš

Beilstein J. Org. Chem. 2026, 22, 782–794, doi:10.3762/bjoc.22.60

• of appended halogens. One reduction and one oxidation processes were found within the available potential window of DCE. Both electrochemical redox processes are irreversible regardless the scan rate, indicating chemical instability of the generated oxidized/reduced forms in the used system. The

• reverse reduction of the chemically modified oxidized form was recorded as a broad peak at significant undervoltage, especially for derivatives 1a–b and 1d–e. The electrochemical data suggest that the first oxidation and the first reduction processes are associated with different parts of the molecule

• corresponding radical anion [27]. In contrast, possible reduction of an aliphatic ester substituent, such as our acrylate pendant, generally requires more negative potentials [28]. On the other hand, the first oxidation observed at ca. +1.47 V is most likely associated with the alkoxy donor fragment, in

Preparation of 3-(alkylamino)imidazo[1,2-a]pyridine-2-carbaldehydes via Kornblum oxidation and unexpected ring-opening reactions of the corresponding alcohols under oxidative conditions

• Sandile J. Mkhize,
• Memory Zimuwandeyi,
• Manuel A. Fernandes,
• Amanda L. Rousseau and
• Moira L. Bode

Beilstein J. Org. Chem. 2026, 22, 763–770, doi:10.3762/bjoc.22.58

• oxidation conditions, reaction in the presence of DMSO and NaHCO3 under conventional or microwave heating to ≈100 °C, were applied to the bromides derived from these alcohols by treatment with PBr3, resulting in the desired aldehydes which successfully underwent reductive amination reactions with 2

• -chloroaniline. Alternative oxidation conditions such as PCC, IBX or T. versicolor laccase applied to the alcohols led only to oxidative ring-opening to give oxalamide derivatives, with no aldehyde being isolated. Keywords: 3-aminoimidazo[1,2-a]pyridine-2-carbaldehydes; Groebke–Blackburn–Bienaymé reaction

• ; Kornblum oxidation; oxidative ring-opening; reductive amination; Introduction Imidazo[1,2-a]pyridines display a wide range of different biological activities, and this scaffold has come to be regarded as being biologically privileged [1]. Compounds containing the imidazo[1,2-a]pyridine core have been

Synthesis and biological evaluation of new brassinosteroid analogs with C-22 benzoate function

• María Núñez,
• Camila Escobar,
• Mario Párraga,
• Mauricio Soto,
• Luis Espinoza-Catalán,
• Katy Díaz and
• Andrés F. Olea

Beilstein J. Org. Chem. 2026, 22, 753–762, doi:10.3762/bjoc.22.57

• , conjugation and oxidation via dynamic interaction with different phytohormones and on homeostasis mechanisms [52]. Consequently, exogenous application of a growth regulator initiates not only the process leading to a phenotypic response but also all those associated to its own regulation. Thus, only a

Rongalite addition to dienones: diastereoselectivity in cyclic sulfone synthesis; stereochemical rationalization and prospects as a general conjugate nucleophile

• Melina Goga,
• Hao Zong,
• James Franco,
• Jazmine Prana,
• Rudolph Michel,
• Antonia Muro,
• Elana Rubin,
• Janet Brenya,
• Henk Eshuis and
• Magnus W. P. Bebbington

Beilstein J. Org. Chem. 2026, 22, 742–752, doi:10.3762/bjoc.22.56

• molecules are desirable, particularly in the light of the general need for more sustainable chemical synthesis. Recently, there has been significant progress in the use of SO2 equivalents and bulk inorganic high oxidation state sulfur compounds for the direct incorporation of sulfones [2][3]. Despite these

• advances, use of a low-valent sulfur nucleophile for initial installation of the sulfur atom followed by oxidation remains a widespread method, even though it is far from ideal environmentally and also in terms of functional group tolerance [4]. RongaliteTM is a low-cost commodity chemical that has been

• sulfide oxidation. In that early work, the stereochemical analysis was dependent on conformational analysis and comparison of coupling constants in the 1H NMR spectra. Experiments discussed in our inital report confirmed that the reaction proceeded under kinetic control [21]. Closer examination of the

Synthesis of heterocycles based on azomethine ylides from α-amino acids (or amines) and carbonyl compounds

• Ekaterina V. Berezhnaya,
• Alexander I. Ponyaev,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2026, 22, 705–741, doi:10.3762/bjoc.22.55

• using benzyl alcohols as aldehyde precursors to prepare fused heterocycles [84]. The authors note that the iridium-catalyzed oxidation of benzyl alcohol 108 to the corresponding aldehyde initially occurs. This is followed by condensation of the aldehyde with proline (103) and subsequent decarboxylation

Synthesis of depressin, cryptomeridiol and 4-epi-cryptomeridiol enabled by a terpenoid chiral pool-producing platform

• Yao Kong,
• Tao Wang,
• Chen Wang,
• Pengcheng Zhang,
• Yuanning Liu,
• Kaibiao Wang,
• Fen Liu,
• Hongli Jia and
• Zhengren Xu

Beilstein J. Org. Chem. 2026, 22, 683–690, doi:10.3762/bjoc.22.53

• compounds 1, 2, and 3 is depicted in Scheme 1 [40][41][42]. We envisioned that by selective oxidation at C5, compound 1 could be directly obtained from casbene (4). The macrocyclic casbane-type skeleton could be produced by an engineered heterologous host harboring both casbene synthase (CS) and an

• pool’ strategy, the stage was set forth for the late-stage modification of the corresponding terpene skeletons for the synthesis of the targeted natural products (Scheme 2) [55]. Formally, a selective oxidation of the allylic C5 position would give 1 directly (Scheme 2a). Considering the limited

• reports on direct modifications of the casbene skeleton, we thus commenced our synthesis with probing the reactivity of 4 by screening a series of conditions for allylic oxidation (Table S2 in Supporting Information File 1). However, most of the conditions tested did not give satisfactory results, as

Photoorganocatalytic trifluoromethylation of (het)arenes in green conditions

• Egor N. Boronin,
• Svetlana E. Kaurkina,
• Milena M. Svetlakova,
• Anton S. Bolshakov,
• Maxim V. Arsenyev,
• Vasilii F. Otvagin,
• Alexey Yu. Fedorov,
• Timothy Noël and
• Alexander V. Nyuchev

Beilstein J. Org. Chem. 2026, 22, 662–671, doi:10.3762/bjoc.22.50

• conditions. Since the photocatalyst can function as both an oxidizing and a reducing agent, we examined the literature data to evaluate the possible reaction pathway. Based on the experimentally determined oxidation and reduction potentials of the excited state of 3DPAFIPN (E1/2(PC·+/PC*) = −1.38 V, E1/2 (PC

• */PC·−) = 1.09 V) [33], together with the reduction potential of TFAA (Ered = −1.2 V) [34] and the oxidation potential of TMB (Ered = 1.43 V) [35], it can be concluded that in our reaction the photocatalyst acts primarily as an electron donor. Accordingly, for the pair of TFAA and TMB, reduction of

• TFAA is thermodynamically favorable (ΔE = 0.18 V), whereas the oxidation of TMB is disfavored (ΔE = −0.34 V). We next assessed the theoretical feasibility of the proposed mechanism by means of DFT and TDDFT calculations. The results revealed that the reduction of TFAA, followed by the generation of the

Hydrogen production from formic acid catalyzed by NHC–Cu complexes

• Orlando Santoro and
• Catherine S. J. Cazin

Beilstein J. Org. Chem. 2026, 22, 620–627, doi:10.3762/bjoc.22.48

• such as Co [35][36], Ni [37][38], Al [39][40], and Mn [41][42][43] have been released. In this scenario, copper systems remain widely unexplored and, generally, have displayed low activity, regardless of the oxidation state of the Cu precursor and of the presence/absence of additives [44][45][46][47

Computational prediction of C–H hydricities and their use in predicting the regioselectivity of electron-rich C–H functionalisation reactions

• Rasmus M. Borup,
• Nicolai Ree and
• Jan H. Jensen

Beilstein J. Org. Chem. 2026, 22, 603–610, doi:10.3762/bjoc.22.46

• that must be used when applying simple measures of selectivity prediction in a complex setting.” Compound 4 Vermeulen et al. [41] reported the Fe(DPD)-catalysed oxidation of (+)-artemisinin (compound 4). Similarly to nitrene insertion into cycloheximide (compound 2), the reactive site does not

Regioselective approach to 5-arylsulfonylisoxazoles and their antimicrobial activity

• Artem S. Sazonov,
• Dmitry A. Vasilenko,
• Denis V. Porfiriev,
• Yuri K. Grishin,
• Rimma A. Gazzaeva,
• Alisa P. Chernyshova,
• Maxim A. Kryakvin,
• Anna A. Baranova,
• Vera A. Alferova and
• Elena B. Averina

Beilstein J. Org. Chem. 2026, 22, 592–602, doi:10.3762/bjoc.22.45

• nucleophilic aromatic substitution with thiophenols followed by oxidation with m-chloroperbenzoic acid (mCPBA). The scope of the reactions was explored, demonstrating high yields across a variety of functional groups and substituents. Optimized conditions enabled selective oxidation of thioaryl groups to

• as promising antimicrobial agents and provide new insights into their mechanism of action. Keywords: antimicrobial activity; aromatic nucleophilic substitution; isoxazoles; oxidation; sulfonylisoxazoles; Introduction The isoxazole ring represents an important building block for the synthesis of

• common method for the synthesis of substituted isoxazoles is based on the 1,3-dipolar cycloaddition of nitrile oxide with alkynes or alkenes followed by oxidation of the resulting isoxazoline product in the latter case [18][19][20][21][22]. This approach, in three variations, is also applicable to obtain

Melifoliox B, a novel phloroglucin derivative isolated from Melicope barbigera (Rutaceae) and synthesis of new oxidation products from melifoliones A and B

• Horst Weber,
• Kim-Thao Tran-Cong,
• Bernhard Mayer,
• Guido J. Reiss,
• Iryna S. Konovalova,
• Marc S. Appelhans,
• Kenneth R. Wood and
• Claus M. Passreiter

Beilstein J. Org. Chem. 2026, 22, 535–546, doi:10.3762/bjoc.22.39

• to new acetophenones and 2H-chromenes, the dichlormethane extract from leaves of Melicope barbigera A. Gray (Rutaceae) afforded a mixture of the isomeric melifoliones A (1) and B (2) as well as an oxidation product of 2, whose structure was elucidated as the para-quinol 4. For an independent

• benzoxocin derivatives 6 and 7. Oxidation of melifoliones 1 and 2 under a great variety of oxidants and conditions failed to give 3 and 4. Iodine-containing oxidants yielded the products 8, 9, and 10. Combined oxidation with hydrogen peroxide and ferricyanide in alkaline solution resulted in an unexpected

• been described in the literature. Keywords: Melicope barbigera; Melifoliones A and B; new heterocyclic ring systems; new natural compounds; para-quinols; phenol oxidation; Introduction The genus Melicope is a member of the Rutaceae (Citrus family) and contains more than 200 species distributed in the

Modern synthetic pathways towards eribulin and its subunits

• Sebastian Dominik Graf

Beilstein J. Org. Chem. 2026, 22, 495–526, doi:10.3762/bjoc.22.37

• used as a starting material and was protected as acetonide within the first step to enable the reduction of both acid moieties towards 14 (Scheme 2). Bn-protection, followed by oxidation and olefination yielded sulfone 15, which was vinylated leading to 16 as a single diastereomer. Further Grubbs

• and addition of vinylmagnesium bromide, 21 was received and dihydroxylated towards 22 in 5:1 dr. The second path towards 27 commenced with the assembly of 23 from 14 via Bn-protection, following oxidation and Horner–Wadsworth–Emmons (HWE) reaction (Scheme 3). Stereospecific vinylation with a Gilman

• -oxidation (Scheme 4, above). For the assembly of 33, only the hydrolysis of previously reported 32 [75] with Me3SnOH and thioesterification using EtSH and DCC were necessary (Scheme 4, below). Both fragments (31 and 33) were fused together via NHK coupling to furnish 34 in 86% yield. The addition of SrCO3

Synthesis and uranyl(VI) extraction performance of a calix[4]pyrrole–tetrahydroxamic acid receptor

• Sara Karnib,
• Rana Baydoun,
• Wissam Zaidan,
• Nancy AlHaddad,
• Omar El Samad,
• Bilal Nsouli,
• Francine Cazier-Dennin and
• Pierre-Edouard Danjou

Beilstein J. Org. Chem. 2026, 22, 486–494, doi:10.3762/bjoc.22.36

• aqueous solution, hexavalent uranium, the most dominant oxidation state, exists predominantly as the linear uranyl ion UO22+. In this ion, two oxo ligands occupy axial positions while the equatorial plane accommodates four to six donor atoms [74][75]. Complexes of UO22+ often adopt either a pseudoplanar

Cone p-aminocalix[4]arenes enriched with ‘clickable’ alkyne or azide functionalities

• Ilia Korniltsev,
• Vasily Bazhenov,
• Alexander Gorbunov,
• Dmitry Cheshkov,
• Stanislav Bezzubov,
• Vladimir Kovalev and
• Ivan Vatsouro

Beilstein J. Org. Chem. 2026, 22, 399–415, doi:10.3762/bjoc.22.28

• formation of side products, due to acid-promoted cleavage and undesired transformations of the TBS-protected propargyl groups and/or due to unwanted oxidation/nitration of the calixarene core [93]. Indeed, nitration of calixarene 6 has been reported to furnish the desired wide-rim exhaustively nitrated

• closed vessel to prevent the product oxidation. At the work-up step sodium hydroxide was replaced with potassium hydroxide which provided better water solubility of inorganic salts for their extractive removal. As a result, tetraamine 18 having four TBS-protected propargyl groups at the narrow rim was

Electrosynthetic access to unsymmetrical oxaza[8]helicenes with high chiral stability and strong circularly polarized luminescence (CPL)

• Tin Zar Aye,
• Rubal Sharma,
• Muthu Karuppasamy,
• Daiya Suzuki,
• Haruka Nakajima,
• Yoshitane Imai,
• Mitsuhiro Arisawa,
• Mohamed S. H. Salem and
• Shinobu Takizawa

Beilstein J. Org. Chem. 2026, 22, 372–382, doi:10.3762/bjoc.22.25

• hetero[8]helicene (Scheme 1C). This strategy delivers the target scaffold in only three steps from commercially available substrates and exploits the differential oxidation potentials of the two partners to enforce chemoselective cross-annulation. To the best of our knowledge, this represents the

• electrochemical arenol activations reported by Waldvogel and co-workers [46]. Subsequent intramolecular dehydrative cyclization furnishes the desired oxaza[8]helicenes 5. The oxidation-potential gap between 3 and 4 and the reactivity of Int-I thus provides a handle to control chemo- and regioselectivity

• that integrate synthetic accessibility with superior chiral stability and chiroptical performance. Conclusion In summary, we have established an electrosynthetic strategy to access a novel class of unsymmetrical oxaza[8]helicenes by exploiting the differential oxidation potentials of appropriately

Synthesis of tricyclic fused pyrrolidine nitroxides from 2-alkynylpyrrolidine-1-oxyls

• Mark M. Gulman,
• Yuliya F. Polienko,
• Sofia Yu. Trakhininа,
• Yuri V. Gatilov,
• Tatyana V. Rybalova,
• Sergey A. Dobrynin and
• Igor A. Kirilyuk

Beilstein J. Org. Chem. 2026, 22, 344–351, doi:10.3762/bjoc.22.22

• metalation of trimethylsilylacetylene or benzyl propargyl ether with ethylmagnesium bromide. After quenching, removal of the MOP protecting group, and oxidation by atmospheric oxygen the nitroxides 2d and 2e were isolated in 64% and 66% yields, respectively. Terminal alkynes can be converted into

• group, respectively. The elemental analyses data and high-resolution mass spectra (HRMS) of 6a,b were in agreement with the assigned structure. Oxidation of propargyl alcohols is another way to α,β-acetylenic carbonyl compounds [31]. Mild oxidation of propargyl alcohol 2c with activated manganese

Ring contraction and ring expansion reactions in terpenoid biosynthesis and their application to total synthesis

• Nicolas Kratena,
• Nicolas Heinzig and
• Peter Gärtner

Beilstein J. Org. Chem. 2026, 22, 289–343, doi:10.3762/bjoc.22.21

• their unique ring systems, high degree of 3-dimensionality in their structures and oxidation patterns. As obtaining a detailed understanding of a biosynthetic pathway is a dauntingly complex and very labour-intensive process, knowledge about the precise origin of most rearranged terpenoids cannot be

• biosynthesis, when the oxidation state of the terpenoids is being adjusted [28][29][30][31][32][33][34][35][36]. Starting with an already substantial number of these common polycyclic frameworks and adding the almost unlimited variability for oxidative enzymatic C–H functionalisation, it is not surprising that

• ][41]. They contain an iron-protoporphyrin core with a cysteine ligand [42] in the axial position, which cycles through different oxidation states (Fe3+/Fe2+/Fe4+) to form highly reactive oxo species which are effective at abstracting closely positioned aliphatic hydrogens via HAT (hydrogen atom

Arene activation via π-bond localization: concepts and opportunities

• Paul Meiners,
• Julian J. Melder and
• Tobias Morack

Beilstein J. Org. Chem. 2026, 22, 257–273, doi:10.3762/bjoc.22.19

• that accompanies lower metal oxidation states translates directly into heightened reactivity of the η2-bound arene. These successors not only surpass the Os(II) system in their ability to activate coordinated arenes, unveiling previously inaccessible reaction pathways, but also introduce an additional

• metal center with α-pinene and subsequent ligand substitution proceeds with retention of configuration, the corresponding Mo(0) complex undergoes racemization during substitution (Scheme 2A). This obstacle was overcome by a redox-based approach: oxidation of the Mo(0)–α-pinene complex with iodine to a

• nucleophile toward diphenylketene to generate a cyclohexadienyl intermediate that captures a second ketene molecule (Figure 11B). Subsequent ring closure furnishes a product complex that, upon oxidation with molecular oxygen, liberates the [2 + 2 + 2] bis-adduct, dihydroisochroman-3-one, in 73% yield. This

Base-promoted deacylation of 2-acetyl-2,5-dihydrothiophenes and their oxygen-mediated hydroxylation

• Vladimir G. Ilkin,
• Margarita Likhacheva,
• Igor V. Trushkov,
• Tetyana V. Beryozkina,
• Vera S. Berseneva,
• Vladimir T. Abaev,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2026, 22, 192–204, doi:10.3762/bjoc.22.13

• ] and more complex molecules [11]. Rearrangements of the oxidized compounds are equally important transformations [12]. Oxidation of compounds containing a carbonyl group into carboxylic acid derivatives can be divided into two large groups: direct oxidation and oxidative rearrangements. Direct

• oxidation of ketones includes C‒C-bond cleavage, and carboxylic acids are predominantly formed. This can be achieved by the treatment of acyclic ketones with hypohalites [13], in the nitroarene-catalyzed oxidation with oxygen under basic conditions [14] or by the use of hypervalent iodine compounds (Scheme

• phenols [25]. Hocking has described the oxidation of o-hydroxyacetophenone and some benzophenones with an aqueous alkaline hydrogen peroxide solution [26]. The key steps of oxidation of ketones into phenols include: a) nucleophilic addition of the hydroperoxide anion to the carbonyl carbon; b) [1,2]-aryl