Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• selective oxidation of thiepine and selenepine to give rise to the corresponding sulfoxide 29b, selenoxide 29c and sulfone 30b in excellent yields. All the prepared chalcogen-doped HBC derivatives exhibit good solubility in organic solvents, in line with their highly distorted saddle-shaped or helical

Selective and scalable oxygenation of heteroatoms using the elements of nature: air, water, and light

• Damiano Diprima,
• Hannes Gemoets,
• Stefano Bonciolini and
• Koen Van Aken

Beilstein J. Org. Chem. 2023, 19, 1146–1154, doi:10.3762/bjoc.19.82

• of heteroatoms, making them a promising alternative to traditional oxidants in the chemical industry [9]. Our interest in sustainable oxidation methodologies led us to study the selective oxidation of various heteroatoms to their corresponding oxides, including sulfides to sulfoxides, phosphine to

Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview

• Louis Monsigny,
• Floriane Doche and
• Tatiana Besset

Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35

• methyl, methoxy or methylthio groups (17b–d) or by halogen (17e) was achieved (Scheme 8, up to 77% yield). Note that in case of disubstituted 2-(4-ethoxy-3-fluorophenyl)pyridine (17h), the expected product 18h was isolated in 31% yield. Moreover, selective oxidation of the SCF3 residue into the

• approach. Of high interest, the modularity of the SCF2CO2Et was highlighted by its conversion into various other fluorinated residues (amide, carboxylic acid) and its selective oxidation into the corresponding sulfoxide and sulfone. I.5) Trifluoromethylselenolation of aromatic and vinylic C(sp2)–H bonds by

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• to both, cleavage of the Piv group and reduction of the aldehyde yielding the diol 147. Selective oxidation [67] of the benzyl alcohol with MnO2 gave the compound 148, which was esterified with S-acetylthioacetic acid (129) and reduced to the benzyl alcohol 150. Deacetylation followed by

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

• oxidation of substrates with activated CH-bonds, such as alkylarenes (Scheme 6). At higher temperatures, even unactivated alkanes can be functionalized [75][81]. The NHPI/Co(OAc)2 system was successfully employed for the selective oxidation of methylarenes to aromatic carboxylic acids [78] (in AcOH medium

Lewis acid-catalyzed Pudovik reaction–phospha-Brook rearrangement sequence to access phosphoric esters

• Jin Yang,
• Dang-Wei Qian and
• Shang-Dong Yang

Beilstein J. Org. Chem. 2022, 18, 1188–1194, doi:10.3762/bjoc.18.123

• Jin Yang Dang-Wei Qian Shang-Dong Yang State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. China State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Lanzhou 730000, P. R. China 10.3762/bjoc.18.123 Abstract

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

• -doped diamond electrode; electrosynthesis; oxidation; Introduction Selective oxidation of aromatic alkyl side chains is an important molecular transformation process to obtain various rubbers, resins, fine chemicals, and other industrial products [1][2]: terephthalic acid from p-xylene, cumene

Electrochemical Friedel–Crafts-type amidomethylation of arenes by a novel electrochemical oxidation system using a quasi-divided cell and trialkylammonium tetrafluoroborate

• Hisanori Senboku,
• Mizuki Hayama and
• Hidetoshi Matsuno

Beilstein J. Org. Chem. 2022, 18, 1040–1046, doi:10.3762/bjoc.18.105

• in selective oxidation of the solvent, DMA, which is the substance with the largest amount at the anode [28][29]. Conclusion We have developed a novel electrochemical oxidation system using a quasi-divided cell and trialkylammonium tetrafluoroborates, especially iPr2NHEtBF4, both as a supporting

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

• manganese(II) naphthenate (MnPc)-catalyzed oxidation of 16 to furnish 10 in 60% yield with 75.6% conversion and 80% selectivity (Table 1, entry 8) [54]. The MnPc catalyst improves the stability of H2O2 and thus promotes a selective oxidation [54]. The approach developed by Beller’s group, which applied a

• -methylnaphthol (17) oxidation occurs via a thermal ISC (spin inversion) [73]. Additionally, a zwitterionic intermediate formed in the rate-limiting step contributes significantly to the O2-based selective oxidation. However, this oxidation mechanism could be modified by the addition of initiators or bases and

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• functionalization of C–H bonds brings reaction economy and effectiveness. However, owing to the rifeness of the reactivity-similar C–H bonds, it is hard to achieve discriminate control over the product site-selectivity. In nature, the site-selective oxidation of C–H bonds is facilitated by enzymes with the donor

• by water-soluble cavitands E and F. Site-selective hydrogenation of polyenols mediated by supramolecular encapsulated rhodium catalyst. Site-selective oxidation of steroids using cyclodextrin as the anchoring template. Site-selective oxidations of linear diterpenoids with the help of cage host A

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

Cerium-photocatalyzed aerobic oxidation of benzylic alcohols to aldehydes and ketones

• Girish Suresh Yedase,
• Sumit Kumar,
• Jessica Stahl,
• Burkhard König and
• Veera Reddy Yatham

Beilstein J. Org. Chem. 2021, 17, 1727–1732, doi:10.3762/bjoc.17.121

• ; aldehydes; cerium; oxidation; ketones; visible light; Introduction The selective oxidation of alcohols to carbonyl compounds [1][2] is an important process for producing a wide range of value-added fine chemicals [3][4][5][6]. In the traditional oxidation process stoichiometric amounts of oxidants such as

• yields (5 and 7%, respectively). In addition, when the mixture of 3-phenylproponol (1ah) and 3-bromobenzylic alcohol (1t) was subjected to the standard reaction conditions, we observed the selective oxidation of the benzylic alcohol giving the expected product in 44% yield (Scheme 3). The efficiency of

• 4.3 mmol of 1a and reaction time was 72 h; b42 h reaction time; c48 h reaction time. Selective oxidation of 3-bromobenzyl alcohol in the presence of 3-phenylpropanol. Compound 1af was recovered unchanged from the reaction mixture. Optimization of the reaction conditions.a Supporting Information

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 novel and robust heterogeneous Cu catalyst using modified lignosulfonate as support for the synthesis of nitrogen-containing heterocycles

• Bingbing Lai,
• Meng Ye,
• Ping Liu,
• Minghao Li,
• Rongxian Bai and
• Yanlong Gu

Beilstein J. Org. Chem. 2020, 16, 2888–2902, doi:10.3762/bjoc.16.238

• and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P. R. China 10.3762/bjoc.16.238 Abstract A waste biomass, sodium lignosulfonate, was treated with sodium 2-formylbenzenesulfonate, and the phenylaldehyde condensation product was then used as

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

Oxime radicals: generation, properties and application in organic synthesis

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Alexander S. Budnikov and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

• of the richest families of stable and persistent organic radicals with applications ranging from catalysis of selective oxidation processes and mechanistic studies to production of polymers, energy storage, magnetic materials design and spectroscopic studies of biological objects. Compared to other N

• as scavengers of C-centered radicals [9] and selective oxidation organocatalysts (for example, in the oxidation of alcohols to the corresponding carbonyl compounds [10][11]). Recently, highly reactive imidoxyl radicals (Figure 1, II) have found a wide application in the processes of hydrogen atom

Synthesis of acremines A, B and F and studies on the bisacremines

• Nils Winter and
• Dirk Trauner

Beilstein J. Org. Chem. 2019, 15, 2271–2276, doi:10.3762/bjoc.15.219

• acremines A and B. The dimerization of acremine F to bisacremine E was investigated but could not be achieved, shedding light on the formation of the acremine dimers in nature. Keywords: meroterpenoid; natural product; selective oxidation; total synthesis; Introduction Endophytic fungi grow in a symbiotic

• modestly enantioselective oxidation and a highly enantioselective reduction with kinetic resolution to access the acremine framework. The route proved to be scalable and delivered 300 mg of the natural product. Acremine F could further be converted into acremines A (1) and B (2) by a selective oxidation

• transformation requires enzymatic catalysis in nature. Selected members of the acremine family [3][4][5]. Retrosynthetic analysis of acremine F (5). Total synthesis of acremine F (5). Synthesis of acremines A and B through selective oxidation of acremine F. Proposed biomimetic dimerization of 5. Attempted

Metal-free mechanochemical oxidations in Ertalyte^® jars

• Andrea Porcheddu,
• Francesco Delogu,
• Lidia De Luca,
• Claudia Fattuoni and
• Evelina Colacino

Beilstein J. Org. Chem. 2019, 15, 1786–1794, doi:10.3762/bjoc.15.172

• a mechanochemical process. Keywords: AZADO; Ertalyte®; green chemistry; mechanochemistry; NaOCl·5H2O; selective oxidation; TEMPO; Introduction The conversion of primary and secondary alcohols to the corresponding carbonyl compounds (aldehydes and ketones, respectively) is of such importance in

• the atom efficiency [4][5]. The discovery of (2,2,6,6-tetramethylpiperidin-1-yl)oxyl, commonly known as TEMPO by Lebedev and Kazarnowskii in 1960 has been hailed as a significant breakthrough in the field of redox reactions, allowing the fast and selective oxidation of alcohols to the related carbonyl

• synthetic route that can be scaled up to pilot and industrial levels. Results and Discussion Since the most commonly employed oxidizing agents are solid reagents, we decided to develop an efficient and eco-friendly process for the selective oxidation of alcohols to the corresponding aldehydes/ketones based

Diastereo- and enantioselective preparation of cyclopropanol derivatives

• Marwan Simaan and
• Ilan Marek

Beilstein J. Org. Chem. 2019, 15, 752–760, doi:10.3762/bjoc.15.71

• cyclopropylmagnesium species 6MgBr, the selective oxidation reaction of the copper species, resulting from a transmetalation reaction, was similarly achieved by reaction with oxenoid [71][79][80][86][87][88][89]. In all cases, cyclopropanols 7 were obtained as single diastereoisomer (dr 98:2:0:0) with excellent

Selective benzylic C–H monooxygenation mediated by iodine oxides

• Kelsey B. LaMartina,
• Haley K. Kuck,
• Linda S. Oglesbee,
• Asma Al-Odaini and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2019, 15, 602–609, doi:10.3762/bjoc.15.55

• hypervalent iodine species as a terminal oxidant. Combinations of ammonium iodate and catalytic N-hydroxyphthalimide (NHPI) were shown to be effective in the selective oxidation of n-butylbenzene directly to 1-phenylbutyl acetate in high yield (86%). This method shows moderate substrate tolerance in the

Thiol-free chemoenzymatic synthesis of β-ketosulfides

• Adrián A. Heredia,
• Martín G. López-Vidal,
• Marcela Kurina-Sanz,
• Fabricio R. Bisogno and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2019, 15, 378–387, doi:10.3762/bjoc.15.34

• temperature one-pot two-step preparation of the phenacyl allyl sulfide 2h. cIsolated yield. Selective oxidation of the β-ketosulfide 2a. Screening of hydrolases and conditions towards a model substrate.a Lipase-catalysed hydrolysis–protonation sequence over a series of β-thioalkyl enol esters.a Supporting

Synthesis of nonracemic hydroxyglutamic acids

• Dorota G. Piotrowska,
• Iwona E. Głowacka,
• Andrzej E. Wróblewski and
• Liwia Lubowiecka

Beilstein J. Org. Chem. 2019, 15, 236–255, doi:10.3762/bjoc.15.22

• nitrogen was protected as N-Boc to furnish (4R,5R)-47. Under basic conditions the pyrrolidin-2-one ring was cleaved to provide a five-carbon chain of the target molecule. The final steps included esterification, desilylation and selective oxidation of the hydroxymethyl group followed by esterification

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• such a mild and selective oxidation. MacMillan and co-workers have recently developed a method for the bioconjugation of peptides by radical decarboxylation of the C-terminus of peptides and subsequent Giese-type addition to Michael acceptors. This is performed under blue light irradiation, using

Preparation and X-ray structure of 2-iodoxybenzenesulfonic acid (IBS) – a powerful hypervalent iodine(V) oxidant

• Irina A. Mironova,
• Pavel S. Postnikov,
• Rosa Y. Yusubova,
• Akira Yoshimura,
• Thomas Wirth,
• Viktor V. Zhdankin,
• Victor N. Nemykin and
• Mekhman S. Yusubov

Beilstein J. Org. Chem. 2018, 14, 1854–1858, doi:10.3762/bjoc.14.159

• product of its acetylation Dess–Martin periodinane (DMP) are the most common oxidants used for selective oxidation of alcohols to carbonyl compounds as well as for a variety of other synthetically useful oxidative transformations [10][11]. IBX and DMP are mild oxidants with a relatively low reactivity

Cobalt–metalloid alloys for electrochemical oxidation of 5-hydroxymethylfurfural as an alternative anode reaction in lieu of oxygen evolution during water splitting

• Jonas Weidner,
• Stefan Barwe,
• Kirill Sliozberg,
• Stefan Piontek,
• Justus Masa,
• Ulf-Peter Apfel and
• Wolfgang Schuhmann

Beilstein J. Org. Chem. 2018, 14, 1436–1445, doi:10.3762/bjoc.14.121

• comparatively lower potential than that required for water oxidation. Suitable catalysts are, however, required to achieve a selective oxidation of HMF to FDCA with a high conversion yield. We recently demonstrated that the modification of cobalt with boron and phosphorus alters the electronic and lattice