Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• of palladium catalyst and gaseous oxygen as the terminal oxidant (Scheme 65). 1.8 From other compounds In 2016, Shi et al. have developed an unique, conditions-controlled [Rh2(esp)2] (esp = α,α,α’,α’-tetramethyl-1,3-benzenedipropionic acid)-catalyzed reaction of N-sulfonyl-1,2,3-triazoles 235 leading

Self-optimisation and model-based design of experiments for developing a C–H activation flow process

• Alexander Echtermeyer,
• Yehia Amar,
• Jacek Zakrzewski and
• Alexei Lapkin

Beilstein J. Org. Chem. 2017, 13, 150–163, doi:10.3762/bjoc.13.18

• compounds, except for the oxidant PhI(OAc)2 which is of zero-order dependency [21]. In addition, the overall and the component mole balances, Equation 7 and Equation 8, were written for the process model, where V denotes the reaction volume. The balances were constructed for a single reaction mixture

• includes the C–H activation. 1: starting material, 1∙HOAc: coordinated starting material, Pd(OAc)2: catalyst, 2: product, PhI(OAc)2: oxidant. Details of information considered as a priori knowledge in this study and source of this knowledge. Results of the MBDoE for kinetic parameters, showing the number

Synthesis and evaluation of anti-oxidant and cytotoxic activities of novel 10-undecenoic acid methyl ester based lipoconjugates of phenolic acids

• Naganna Narra,
• Shiva Shanker Kaki,
• Rachapudi Badari Narayana Prasad,
• Sunil Misra,
• Koude Dhevendar,
• Venkateshwarlu Kontham and
• Padmaja V. Korlipara

Beilstein J. Org. Chem. 2017, 13, 26–32, doi:10.3762/bjoc.13.4

• structures were confirmed by spectral data. The anti-oxidant activity of the synthesized lipoconjugates of phenolic acids was studied by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and also by the inhibition of linoleic acid oxidation in micellar medium by differential scanning

• calorimetry (DSC). The prepared compounds were also screened for their cytotoxic activity against five cell lines. It was observed that the lipoconjugates of caffeic acid, sinapic acid, ferulic acid, and coumaric acid displayed anticancer and anti-oxidant properties. The anticancer properties of these

• are a class of natural compounds which are found ubiquitously in the plant kingdom. They are reported to possess a wide range of biological properties like anti-oxidant, antimicrobial, anti-inflammatory, anticarcinogenic and antiviral activities [1]. The phenolic acids are also reported to show in

Copper-catalyzed asymmetric sp³ C–H arylation of tetrahydroisoquinoline mediated by a visible light photoredox catalyst

• Pierre Querard,
• Inna Perepichka,
• Eli Zysman-Colman and
• Chao-Jun Li

Beilstein J. Org. Chem. 2016, 12, 2636–2643, doi:10.3762/bjoc.12.260

• [2]. The emerging and expanding field of visible-light-mediated photoredox catalysis presents unique opportunities for the conception of new synthetic routes [3][4][5][6][7][8][9][10][11][12]. Upon exposure to visible light, photoredox catalysts can function as both reductant and oxidant, thereby

• temperature in the reaction with copper(I) bromide caused a significant drop in yield. During optimisation of the reaction system, TBHP was found to be the best external oxidant for this reaction over many others [31]. To accelerate the reaction at lower temperature, we reasoned that a light-mediated

• stereofacial nucleophilic addition of the arylboronic acid to produce the desired enantioenriched arylated product VII. The Ir(III) is regenerated in the presence of the sacrificial external oxidant TBHP. Conclusion In conclusion, we have successfully developed a highly efficient light-mediated coupling method

Synthesis of polyhydroxylated decalins via two consecutive one-pot reactions: 1,4-addition/aldol reaction followed by RCM/syn-dihydroxylation

• Michał Malik and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2016, 12, 2602–2608, doi:10.3762/bjoc.12.255

• the subsequent syn-dihydroxylation with NaIO4 as a stoichiometric oxidant in the presence of catalytic amounts of CeCl3 (15 mol %). As a result, in the case of diolefin 25 as substrate, a separable mixture of diols (dr = 8:1; 27 being the major isomer) was obtained in fair yield (56%). The same

Facile synthesis of indolo[3,2-a]carbazoles via Pd-catalyzed twofold oxidative cyclization

• Chao Yang,
• Kai Lin,
• Lan Huang,
• Wei-dong Pan and
• Sheng Liu

Beilstein J. Org. Chem. 2016, 12, 2490–2494, doi:10.3762/bjoc.12.243

• technical simplicity, we prefer to employ air at ambient pressure as the terminal oxidant, and hence only the combination of bases (K2CO3 and NaOt-Bu) and solvents (AcOH, TFA, PivOH) were screened to promote the demanding transformation (Table 1). Initial investigations were performed with 2a and catalytic

Selective and eco-friendly procedures for the synthesis of benzimidazole derivatives. The role of the Er(OTf)₃ catalyst in the reaction selectivity

• Natividad Herrera Cano,
• Jorge G. Uranga,
• Mónica Nardi,
• Antonio Procopio,
• Daniel A. Wunderlin and
• Ana N. Santiago

Beilstein J. Org. Chem. 2016, 12, 2410–2419, doi:10.3762/bjoc.12.235

• oxidant and dioxane as solvent [40][41] or in the presence of [Ru(bpy)3Cl2] or Ir(dfppy)2(phen)PF6 as catalysts [42] (Table 1, entries 29–31). The major disadvantage of these methods, however, is the cost of these catalysts. Thus, comparing previous reports with our current method, it is concluded that

Solvent-free, visible-light photocatalytic alcohol oxidations applying an organic photocatalyst

• Martin Obst and
• Burkhard König

Beilstein J. Org. Chem. 2016, 12, 2358–2363, doi:10.3762/bjoc.12.229

• flavin derivatives in general are well-known blue-light absorbing photocatalysts, which can oxidize a variety of substrates under aerobic conditions with oxygen as terminal oxidant. Flavins were studied extensively for the oxidation of alcohols, amines, methylbenzenes, styrenes, and phenylacetic acids [9

TBHP-mediated highly efficient dehydrogenative cross-oxidative coupling of methylarenes with acetanilides

• Cui Chen,
• Weibing Liu and
• Peng Zhou

Beilstein J. Org. Chem. 2016, 12, 2250–2255, doi:10.3762/bjoc.12.217

• are rather limited, and which would be an important complement to the conventional C–N forming strategies. Herein, we disclose a dehydrogenative C–N cross-oxidative-coupling reaction of methylarenes with acetanilides, using TBHP as an oxidant to afford N-arylamides in moderate to good yields (Scheme 1

The direct oxidative diene cyclization and related reactions in natural product synthesis

• Juliane Adrian,
• Leona J. Gross and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2016, 12, 2104–2123, doi:10.3762/bjoc.12.200

• ). These compounds can only form mono-esters with the metal oxidant (Scheme 3). Therefore, they exhibit a different reactivity and a less ordered transition geometry in the oxygen transfer reaction and are thus categorized as a distinct class of oxidative cyclization, referred to as type C reaction. In

Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

• Dominik Urselmann,
• Konstantin Deilhof,
• Bernhard Mayer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2016, 12, 2055–2064, doi:10.3762/bjoc.12.194

• )phenothiazines. Most remarkably, the oxidative conditions of the central Glaser step employing air as oxidant does not interfere with the oxidation sensitive (oligo)phenothiazinyl moieties. The electronic properties of the obtained three thienyl-bridged systems were intensively studied by UV–vis and fluorescence

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

• Lucie Brulíková,
• Aidan Harrison,
• Marvin J. Miller and
• Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

• the corresponding hydroxamic acids using, for example, periodate [14], Dess–Martin periodinane [64], Swern oxidation conditions [65], lead and silver oxide [66], and transition-metal oxidation with peroxide as the oxidant [67]. In a recent work by Tusun dirhodium caprolactamate [68], and the aerobic

• hetero-Diels–Alder reaction by vanadium in the presence of the oxidant CHP (cumyl hydroperoxide). Regioselectivity of solution-phase nitroso hetero-Diels–Alder reaction with acyl and aryl nitroso dienophiles. Favored regioisomeric outcome for the solution and solid-phase reactions, giving hetero-Diels

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• by Ube Industries [59]. The EniChem process involved an oxidative carbonylation of methanol, i.e., the reaction of methanol with carbon monoxide and oxygen catalyzed by cuprous chloride, while the Ube process used an oxidative carbonylation of methanol via methyl nitrite using NOx as oxidant, instead

A flow reactor setup for photochemistry of biphasic gas/liquid reactions

• Josef Schachtner,
• Patrick Bayer and
• Axel Jacobi von Wangelin

Beilstein J. Org. Chem. 2016, 12, 1798–1811, doi:10.3762/bjoc.12.170

• application to oxidations with gaseous oxygen as the stoichiometric oxidant. The range of application of such a modular home-built reactor is 0.04–0.5 mmol min−1 substrate throughput, 0.4–2.5 mL min−1 liquid phase flow rates, −40 to 60 °C, and 5–40 bar oxygen pressure. The device can be easily assembled

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• benzeneseleninoperoxoic anhydride [PhSe(O)O]2O in the first step, which then transforms to the active oxidant benzeneseleninoperoxoic acid PhSe(O)OOH [233]. The Baeyer–Villiger oxidation of (E)-α,β-unsaturated ketones to (E)-vinyl esters was performed with hydrogen peroxide and dibenzyl diselenide as pre-catalyst at room

• activities, including antibacterial, antiviral, antifungal, anti-allergic, anti-oxidant, and anti-inflammatory [348][349]. The treatment of endoperoxide 238 with Et3N gave 1,4-diketone 240 in quantitative yield instead of expected hydroxy ketone 239 (Scheme 73) [350][351][352]. The endoperoxide 238 is

Catalytic Chan–Lam coupling using a ‘tube-in-tube’ reactor to deliver molecular oxygen as an oxidant

• Carl J. Mallia,
• Paul M. Burton,
• Alexander M. R. Smith,
• Gary C. Walter and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2016, 12, 1598–1607, doi:10.3762/bjoc.12.156

• Abstract A flow system to perform Chan–Lam coupling reactions of various amines and arylboronic acids has been realised employing molecular oxygen as an oxidant for the re-oxidation of the copper catalyst enabling a catalytic process. A tube-in-tube gas reactor has been used to simplify the delivery of the

• nucleophilic partner, moderate to good yields were obtained (56–71% yields, 9 examples). More recently the Tranmer group reported the use of a copper-filled column as a catalyst with TEMPO as the co-oxidant in acetonitrile (acetic acid additive) with moderate to good yields of the coupled products being

• obtained (25–79% yields, 16 examples) [14]. The use of a copper tubing which serves as both the reactor and the catalyst with tert-butyl peroxybenzoate as the oxidant in acetonitrile was also described but was outperformed by the copper filled column system. Although the use of elemental copper is

Synthesis of 2-oxindoles via 'transition-metal-free' intramolecular dehydrogenative coupling (IDC) of sp² C–H and sp³ C–H bonds

• Nivesh Kumar,
• Santanu Ghosh,
• Subhajit Bhunia and
• Alakesh Bisai

Beilstein J. Org. Chem. 2016, 12, 1153–1169, doi:10.3762/bjoc.12.111

• equiv of NaOt-Bu [38][39]. In the same year, Taylor and co-workers independently reported synthesis of 2-oxindoles in the presence of Cu(OAc)2·H2O as oxidant (Scheme 1) [40][41][42][43][44]. Experimental evidence suggests involvement of a free-radical process in the addition of α-carbonylalkyl radicals

• -catalyzed decarboxylative strategies [47]. Results and Discussion We decided to use iodine as an oxidant for the synthesis of 2-oxindoles [48][49][50][51][52][53], starting from β-N-arylamido ester 3a and methyl iodide as the substrates (Table 1). An elaborate optimization study suggested that the

• followed a two-step protocol: In first step a C-alkylation of β-N-arylamido benzylester in presence of 1.2 equivalents of NaH and alkylating agent afford compound (±)-7g in good yields (74%), followed by an oxidative coupling in presence of 1.2 equivalents of KOt-Bu and iodine or NIS as oxidant. Next, we

Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(−)-myrtenol nitrate

• Sean P. Bew,
• Glyn D. Hiatt-Gipson,
• Graham P. Mills and
• Claire E. Reeves

Beilstein J. Org. Chem. 2016, 12, 1081–1095, doi:10.3762/bjoc.12.103

• and high NO concentration. They compared their results with field observations, collected during the Southern oxidant and Aerosol Study (SOAS) campaign conducted in 2013, and model simulations. These studies identified NO as the limiting factor in IPN production [11]. Schwantes et al. reported a

Antibacterial structure–activity relationship studies of several tricyclic sulfur-containing flavonoids

• Lucian G. Bahrin,
• Henning Hopf,
• Peter G. Jones,
• Laura G. Sarbu,
• Cornelia Babii,
• Alina C. Mihai,
• Marius Stefan and
• Lucian M. Birsa

Beilstein J. Org. Chem. 2016, 12, 1065–1071, doi:10.3762/bjoc.12.100

• display antibacterial, antiviral, antifungal, anti-inflammatory and anticancer properties [4][5][6][7][8][9][10]. Their polyphenolic structure also gives them excellent anti-oxidant and cardioprotective properties [11][12]. Our research group has recently reported the antibacterial properties of a new

Cationic Pd(II)-catalyzed C–H activation/cross-coupling reactions at room temperature: synthetic and mechanistic studies

• Takashi Nishikata,
• Alexander R. Abela,
• Shenlin Huang and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2016, 12, 1040–1064, doi:10.3762/bjoc.12.99

• partners, however, 847% (TON = 8.5) and 467% (TON = 4.7) yields of the products were obtained, respectively, supporting a key role for BQ in regeneration of the active dicationic species (PdL4(BF4)2). Benzoquinone (BQ) has been well studied as an oxidant for Pd(0) to Pd(II) processes, generating

• reactions. Unlike traditional Suzuki–Miyaura coupling reactions [241][242][243], C–H coupling reactions catalyzed by a cationic palladium(II) complex require an oxidant instead of a strong base, but otherwise likely share a number of features with this widely used C–C bond-forming process. The reaction also

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• achieve the catalytic kinetic resolution of readily available racemic 3-hydroxy-3-substituted oxindoles, giving the enantiopure 3-hydroxyoxindoles with excellent enantioselectivities (Scheme 45) [62]. In this reaction, the oxidant MnO2 was considered to be important for the reactvity and selectivity and

The synthesis of functionalized bridged polycycles via C–H bond insertion

• Jiun-Le Shih,
• Po-An Chen and
• Jeremy A. May

Beilstein J. Org. Chem. 2016, 12, 985–999, doi:10.3762/bjoc.12.97

• oxide oxidant. Notably, a hindered ligand was again necessary for bridged-bicycle formation – in this case the diadamantyl phosphine 106. The Thorpe–Ingold effect was also found to be highly beneficial for the reaction. An interesting mechanistic study using a less selective substrate showed that the

Nucleic acids through condensation of nucleosides and phosphorous acid in the presence of sulfur

• Tuomas Lönnberg

Beilstein J. Org. Chem. 2016, 12, 670–673, doi:10.3762/bjoc.12.67

• polymerization. Proposed oxidants for prebiotic phosphite chemistry include H2O2 and Fe(III). The present paper describes the polymerization of thymidine and triethylammonium phosphite, with elemental sulfur acting as the oxidant. Up to pentameric oligonucleotides with internucleosidic phosphorothioate linkages

Unconventional application of the Mitsunobu reaction: Selective flavonolignan dehydration yielding hydnocarpins

• Guozheng Huang,
• Simon Schramm,
• Jörg Heilmann,
• David Biedermann,
• Vladimír Křen and
• Michael Decker

Beilstein J. Org. Chem. 2016, 12, 662–669, doi:10.3762/bjoc.12.66

• multiple biological activities and promising therapeutic applications, such as hepatoprotection, antitumor, antiproliferative and anti-oxidant properties [1]. The standardized extract of S. marianum fruits contains the so-called silymarin complex, and is used as the main active component mixture of Legalon

A selective and mild glycosylation method of natural phenolic alcohols

• Mária Mastihubová and
• Monika Poláková

Beilstein J. Org. Chem. 2016, 12, 524–530, doi:10.3762/bjoc.12.51

• -glucopyranoside (vanillyl β-D-glucoside, 1) isolated from the exocarp of Juglans mandshurica Maxim showed antibacterial activity [1]. A wide range of pharmacological effects, e.g., anti-oxidant, anti-inflammatory, anticancer, hepatoprotective, cardioprotective, neuroprotective, antidiabetic, and antiviral