Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

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

• colleagues firstly demonstrated that the decomposition of tert-butyl hydroperoxide (TBHP) by Co(II) naphthenate proceeds via a chain mechanism, leading to the formation of tert-butoxy and tert-butylperoxy radicals (Scheme 4) [24]. When cyclohexene (1) and oct-1-ene (3) were added, the corresponding products

• recombination of IV with tert-butylperoxy radical provides the target product 22 (step J). The peroxidation of 2-oxoindoles 23, barbituric acids 25, and 4-hydroxycoumarins 27 by TBHP and α-cumyl hydroperoxide was carried out with the application of catalytic systems based on Co(II) [49], Mn(III) [50], and Fe(II

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

• developed. NMR studies confirmed the role of in-situ-generated hydroperoxide in the conversion. The protocol was applied to a diverse range of substrates to access the target products in good to excellent yields. A structure–activity study for the 5-substituted-2-hydroxybenzophenones towards UV-protection

• abilities has been verified by mathematical calculations. Keywords: decarbonylation–oxidation; hydroperoxide; 2-hydroxybenzophenone; transition-metal-free; UV-protection; Introduction Benzophenone compounds are ubiquitous in nature, and show biological activities such as anti-inflammatory, antiviral, and

• protocol using a hydroperoxide (Figure 2d) gave us an idea that the use of an in-situ-generated hydroperoxide may trigger the reaction, and may avoid the use of transition metal in the reaction. Many solvents, e.g., tetrahydrofuran (THF), dioxanes etc. are known for producing hydroperoxides in situ on long

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

• . For example, Liu and colleagues demonstrated the electrochemical oxidation of benzylic C–H bonds to ketones using tert-butyl hydroperoxide as the radical initiator [14]. This method was applied to functionalize bioactive molecules, with celestolide, ibuprofen methyl ester, and papaverine being

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

Tandem Hock and Friedel–Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold

• Viktoria A. Ikonnikova,
• Cristina Cheibas,
• Oscar Gayraud,
• Alexandra E. Bosnidou,
• Nicolas Casaretto,
• Gilles Frison and
• Bastien Nay

Beilstein J. Org. Chem. 2024, 20, 162–169, doi:10.3762/bjoc.20.15

• one-pot transformation from readily available benzyl(prenyl)malonate substrates. After the photooxygenation of the prenyl moiety, the resulting hydroperoxide was directly engaged in a Hock cleavage by adding a Lewis acid. The presence of an aromatic nucleophile in the reaction mixture and that of a

• C–C bond adjacent to the hydroperoxide group (Scheme 1a). The best-known application of this reaction is the cumene process, which allows the production of millions of tons of phenol each year [2]. The reaction has also been used in an industrial synthesis of artemisinin [3]. Allylic hydroperoxides

• ), successively involving a Schenck-ene photooxygenation of an alkene A, an acid-catalyzed Hock cleavage of hydroperoxide B generating an aldehyde derivative C, and an acid-catalyzed Friedel–Crafts reaction in the presence of an aromatic nucleophile leading to D [17]. In principle, a second Friedel–Crafts

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• 1H-tetrazole to produce the trialkyl phosphite 8.3 that was oxidized with tert-butyl hydroperoxide to produce phosphate 8.4. Then, β-elimination of the cyanoethyl protecting group produced PAF with a global yield of 70%. The limit of this method arises from the instability of the precursor 8.1 for

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• 2010, Schnürch et al. utilized Fe(NO3)3 as the catalyst and TBHP (tert-butyl hydroperoxide) as the oxidant to realize the CDC of C(sp3)–H/C(sp2)–H bonds under solvent-free conditions (Scheme 21) [82]. However, the desired coupling products were obtained in low to moderate yields. The C–H oxidative

Synthesis and characterisation of new antimalarial fluorinated triazolopyrazine compounds

• Kah Yean Lum,
• Jonathan M. White,
• Daniel J. G. Johnson,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2023, 19, 107–114, doi:10.3762/bjoc.19.11

• -difluoroethanesulfinate (DFES) and zinc difluoromethanesulfinate (DFMS). In brief, a mixture of the respective scaffold, Diversinate™ (2 equiv), and TFA (5 equiv) in DMSO/CH2Cl2/H2O (5:5:2) was stirred for 30 min at room temperature and cooled to 4 °C. Then, aqueous tert-butyl hydroperoxide (TBHP, 70%, 3 equiv) was

Combining the best of both worlds: radical-based divergent total synthesis

• Kyriaki Gennaiou,
• Antonios Kelesidis,
• Maria Kourgiantaki and
• Alexandros L. Zografos

Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1

• rationale, 94 was diverted to produce 100 after basic deprotection of the nonisolated 95. The radical oxidation of the former in the presence of dioxygen and sunlight or a catalytic amount of Mn(OAc)3 led to the creation of the compounds 101 and 102. FGI, followed by the cleavage of the hydroperoxide bond

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

• Elena R. Lopat’eva,
• Igor B. Krylov,
• Dmitry A. Lapshin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

• in oxidative processes for the activation of electrophilic properties of unsaturated substrates or for the activation of hydroperoxide oxidative properties. In Scheme 4A the proposed transition state for the Brønsted acid-catalyzed asymmetric Baeyer–Villiger reaction is shown, in which the

• ][72]. A recent achievement of the enantioselective hydroxylation of α‑aryl-δ-lactams by O2 is shown in Scheme 5 [73] as an example of such organocatalyzed reaction type. Triethyl phosphite is added to reduce a hydroperoxide, which is initially formed by the enolate oxidation with O2. In summary

• radical-chain PINO/NHPI-catalyzed autoxidation proceeds with the selective formation of a benzylic hydroperoxide (Scheme 9), a product that frequently decomposes in the presence of transition metal ions or photoredox catalysts. It was shown that the peroxide is converted to the ketone on the TiO2 surface

A one-pot electrochemical synthesis of 2-aminothiazoles from active methylene ketones and thioureas mediated by NH₄I

• Shang-Feng Yang,
• Pei Li,
• Zi-Lin Fang,
• Sen Liang,
• Hong-Yu Tian,
• Bao-Guo Sun,
• Kun Xu and
• Cheng-Chu Zeng

Beilstein J. Org. Chem. 2022, 18, 1249–1255, doi:10.3762/bjoc.18.130

•  1b). Alternatively, the oxidation of α-C–H of active methylene ketones generate α-carbon-centered radicals, thus providing another way to obtain thiazoles. Recently, Sun et al. reported a tert-butyl hydroperoxide/azodiisobutyronitrile-mediated synthesis of 2-aminothiazoles from active methylene

Electro-conversion of cumene into acetophenone using boron-doped diamond electrodes

• Mana Kitano,
• Tsuyoshi Saitoh,
• Shigeru Nishiyama,
• Yasuaki Einaga and
• Takashi Yamamoto

Beilstein J. Org. Chem. 2022, 18, 1154–1158, doi:10.3762/bjoc.18.119

• 10.3762/bjoc.18.119 Abstract A straightforward electro-conversion of cumene into acetophenone has been reported using boron-doped diamond (BDD) electrodes. This particular conversion is driven by the addition reaction of a cathodically generated hydroperoxide anion to an anodically generated cumyl cation

• hydroperoxide/dicumyl peroxide/phenol from cumene, acetophenone from ethylbenzene, and others. Generally, molecular oxygen has been utilized in the straightforward oxidation of aromatic alkyls. However, since molecular oxygen is highly stable, activation of the molecular oxygen itself is necessary, which

• anode. The role of electrode materials was investigated with electrochemical measurements. Only the BDD anode with a wide potential window can oxidize cumene directly to afford a cumyl cation as the reaction intermediate. Furthermore, acetophenone is produced via cumene hydroperoxide, and this molecular

Structural basis for endoperoxide-forming oxygenases

• Takahiro Mori and
• Ikuro Abe

Beilstein J. Org. Chem. 2022, 18, 707–721, doi:10.3762/bjoc.18.71

• ], which share ≈60% amino acid identity [33]. Both isoforms catalyze the incorporation of two oxygen atoms into arachidonic acid (AA) to form an endoperoxide between C9 and C11 and a peroxide at C15 to generate prostaglandin G2 (PGG2) (Scheme 1) [24][34]. Subsequently, the 15-hydroperoxide in PGG2 is

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• -methylnaphthol (17) to menadione (10) are quite similar to those employed for the oxidation of 2-methylnaphthalene (16) using H2O2, molecular oxygen, and tert-butyl hydroperoxide as oxidizing agents. Similar to the oxidation of compound 16, it is possible to oxidize 2-methylnaphthol (17) with H2O2 to produce

• the predominant path depends mainly on the dioxygen pressure and the solvent nature [73]. Another approach was reported by Zalomaeva and co-workers, which used an iron tetrasulfophthalocyanine (FePcS) supported catalyst (FePcS-SiO2) in combination with the oxidizing agent tert-butyl hydroperoxide for

• dichloromethane and tert-butyl hydroperoxide at 80 °C (Table 2, entry 12). Methylation of 1,4-naphthoquinone Another route to prepare menadione (10) involves the methylation of 1,4-naphthoquinone. Because of their electron-deficient character, quinones are highly reactive with nucleophilic radicals [75]. The most

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• , including kinetic isotope effects and radical trapping, suggested a radical mechanism. The hydroperoxide, in the presence of an iron catalyst, abstracts the hydrogen atom alpha to the heteroatom. The alkyl radical may attack the acrylamide; subsequent intramolecular radical cyclization with the aryl ring

• results, the authors proposed a catalytic cycle (Scheme 12). First, the hydroperoxide, in the presence of an Fe(II) species, generates an Fe(III) intermediate and the alkoxy radical which can oxidize the incoming alcohol 67 to an aldehyde 70. Another equivalent of hydroxy radical, either generated under

• and carbazates 117 (Scheme 24) [112][113]. Both protocols utilized a catalytic loading of FeCl2·4H2O mediated by tert-butyl hydroperoxide. The scopes of both reactions were broad and tolerated a variety of functional groups; however, both groups noted unsubstituted terminal alkenes and N

Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone

• Ilya A. P. Jourjine,
• Lukas Zeisel,
• Jürgen Krauß and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2668–2679, doi:10.3762/bjoc.17.181

• ], CBr4 [22], or peroxides like tert-butyl hydroperoxide (TBHP) [35]. Other oxidative cyclizations have been developed starting from biarylglyoxylic acids (using Na2S2O8) [36], and even 2-methylbiphenyls and 2-(hydroxymethyl)biphenyls can be converted into fluorenones by means of TBHP oxidation [37]. In

• [22], and tert-butyl hydroperoxide [37] (TBHP). Formation of postulated intermediate aminofluorenes of type 5 could not be observed for any of the reactions performed during the initial screening process, and cyclization to the target compound fluorenone (3) was confirmed for only two of the substrate

Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds

• Sumana Mandal,
• Raju D. Chaudhari and
• Goutam Biswas

Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153

• diasteroselectivity of the products formed depends on the heteroatoms involved; azamercuration yields more selectivity than oxymercuration. Nixon et al. reported a Hg(II)-salt-induced alkenyl hydroperoxide 43 cyclization to synthesize cyclic peroxides 44 as the major product, which on further treatment with NaBH4

• gives compound 45 along with the unexpected product 46 (Scheme 17) [63]. Later they had reported the reaction between alkenyl hydroperoxide 47 and aldehydes 48 to form hemiperoxyacetal 49 which subsequently reacted with Hg(OAc)2 and a catalytic amount of perchloric acid (HClO4) forming cyclized product

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• usually mediated by V(V) and V(IV)-oxo-peroxo complexes, which are produced in situ from vanadium-oxo and dioxo precatalysts in the presence of oxidants, such as H2O2, O2, and tert-butyl hydroperoxide (TBHP) [76][77][78][79][80][81][82]. Inorganic acids and chelating and non-chelating carboxylic acids

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

A new and efficient methodology for olefin epoxidation catalyzed by supported cobalt nanoparticles

• Lucía Rossi-Fernández,
• Viviana Dorn and
• Gabriel Radivoy

Beilstein J. Org. Chem. 2021, 17, 519–526, doi:10.3762/bjoc.17.46

• MgO and tert-butyl hydroperoxide (TBHP) as oxidant is presented. This CoNPs@MgO/t-BuOOH catalytic combination allowed the epoxidation of a variety of olefins with good to excellent yield and high selectivity. The catalyst preparation is simple and straightforward from commercially available starting

• greener oxidizing agents as molecular oxygen, hydrogen peroxide or tert-butyl hydroperoxide (TBHP) [14][15][16][17]. However, using any of these oxidants alone results in considerable low reactivity and selectivity in olefin epoxidation reactions. Thus, several transition-metal-based catalytic methods

• , we proposed a plausible mechanistic pathway involving a Co(II)/Co(III) couple species, as depicted in Scheme 1. We assume that tert-butyl hydroperoxide could react with Co(II) species on the surface of the catalyst leading to the formation of metal-oxy radical A. This intermediate could react with

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• were treated with tert-butyl hydroperoxide (TBHP), two flanking benzene rings were found to be cleaved to afford 174 and 175 in impressive yields (Scheme 45) [82][83][84]. Moreover, they observed radical cations 172 and 173 formation when the same compounds were reacted with Br2 or 2,3,5,6-tetrafluoro

Photosensitized direct C–H fluorination and trifluoromethylation in organic synthesis

• Shahboz Yakubov and
• Joshua P. Barham

Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183

Syntheses of spliceostatins and thailanstatins: a review

• William A. Donaldson

Beilstein J. Org. Chem. 2020, 16, 1991–2006, doi:10.3762/bjoc.16.166

• (−)-51 (Scheme 6) [16]. An Achmatowicz oxidation [29] with tert-butyl hydroperoxide catalyzed by VO(acac)2 afforded the hemiketal 52, and the ionic reduction [22] of 52 gave the enone (−)-53. The enone transposition of 53 was effected by the addition of methyl-Grignard, followed by the oxidation with PCC

Metal-free synthesis of phosphinoylchroman-4-ones via a radical phosphinoylation–cyclization cascade mediated by K₂S₂O₈

• Qiang Liu,
• Weibang Lu,
• Guanqun Xie and
• Xiaoxia Wang

Beilstein J. Org. Chem. 2020, 16, 1974–1982, doi:10.3762/bjoc.16.164

• better product yields as compared with the reactions performed at either 70 °C or 90 °C (Table 1, entries 2, 16, and 17). Then, various oxidants such as (NH4)2S2O8, Na2S2O8, TBHP (tert-butyl hydroperoxide), DTBP (di-tert-butyl peroxide), and dioxygen were tested and the results showed that K2S2O8