One-pot odourless synthesis of thioesters via in situ generation of thiobenzoic acids using benzoic anhydrides and thiourea

• Mohammad Abbasi and
• Reza Khalifeh

Beilstein J. Org. Chem. 2015, 11, 1265–1273, doi:10.3762/bjoc.11.141

• containing Et3N and a thick brick-red liquid was formed. Next, H2O (1 mL) and H2O2 (1.2 mmol) were added to the reaction mixture and the resulting solution was stirred for 1 h at room temperature. Extractive work-up with EtOAc followed by silica gel column chromatography afforded benzoyl disulfide in 91

New palladium–oxazoline complexes: Synthesis and evaluation of the optical properties and the catalytic power during the oxidation of textile dyes

• Rym Hassani,
• Mahjoub Jabli,
• Yakdhane Kacem,
• Jérôme Marrot,
• Damien Prim and
• Béchir Ben Hassine

Beilstein J. Org. Chem. 2015, 11, 1175–1186, doi:10.3762/bjoc.11.132

• gap energy values (Eg) ranging between 2.34 and 3.21 eV. Their catalytic activities were tested for the degradation of Eriochrome Blue Black B (a model of azo dyes) in the presence of an ecological oxidant (H2O2). The efficiency of the decolorization has been confirmed via UV–visible spectroscopic

• analysis and the factors affecting the degradation phenomenon have been studied. The removal of the Eriochrome reached high yields. We have found that the complex 9 promoted 84% of color elimination within 5 min (C0 = 30 mg/L, T = 22 °C, pH 7, H2O2 = 0.5 mL) and the energetic parameters have been also

• conditions (t = 10 min, C0 = 30 mg/L, 10 mg of the catalyst, amount of H2O2 = 0.5 mL). Among the six compounds, catalyst 9 was found to be the most active during this study because the corresponding solution became almost colorless within five minutes (Figure 4). As also clearly depicted in Figure 5, the

Properties of PTFE tape as a semipermeable membrane in fluorous reactions

• Brendon A. Parsons,
• Olivia Lin Smith,
• Myeong Chae and
• Veljko Dragojlovic

Beilstein J. Org. Chem. 2015, 11, 980–993, doi:10.3762/bjoc.11.110

• height of the oxalate–rubrene solution in the delivery tube (Figure 12), even over an extended period of time. This indicates that solvent transport was not necessarily a requirement for the delivery of the H2O2 reagent. From the directionality of the PV-PTFE chemiluminescence reaction and lack of change

• in solvent volume in the delivery tube, we conclude that PTFE tape is permeable to small H2O2 molecules but not to the considerably larger oxalate or rubrene molecules. In the reactions where hydrogen peroxide was dissolved in acetonitrile/water (2:1) or tert-butanol/water (2:1) mixtures, the column

• on the left and (b) in the vial in the experiment on the right. (c) The experimental set up with the lights on and (d) lights off. The orange solution contains an oxalate/rubrene mixture in dimethyl phthalate and the clear solution is 10% aqueous H2O2. Progression of PV-PTFE chemiluminescence with

Probing multivalency in ligand–receptor-mediated adhesion of soft, biomimetic interfaces

• Stephan Schmidt,
• Hanqing Wang,
• Daniel Pussak,
• Simone Mosca and
• Laura Hartmann

Beilstein J. Org. Chem. 2015, 11, 720–729, doi:10.3762/bjoc.11.82

• (96% H2SO4 and 30% H2O2, 3:1). The coverslips were rinsed with ultra-pure water and dried in a nitrogen stream. Amine surfaces were prepared via chemical vapor deposition of 3-aminopropyltriethoxysilane (APTES) (50 µL) on a freshly cleaned coverslip were placed in a desiccator and vacuum was applied

Eosin Y-catalyzed visible-light-mediated aerobic oxidative cyclization of N,N-dimethylanilines with maleimides

• Zhongwei Liang,
• Song Xu,
• Wenyan Tian and
• Ronghua Zhang

Beilstein J. Org. Chem. 2015, 11, 425–430, doi:10.3762/bjoc.11.48

• −. The HOO− will be subsequently protonated to yield H2O2 as the by-product. H2O2 was detected after the reaction was completed by using KI/starch indicator (see the Supporting Information File 1). The involvement of radical pathway was supported by experimental result that the reaction was suppressed in

Electrochemical oxidation of cholesterol

• Jacek W. Morzycki and
• Andrzej Sobkowiak

Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45

• compounds 11 (20%) and 12 (43%) were formed. Second, during the reaction with hydrogen peroxide as an oxidant under non-electrochemical conditions no products were detected, which indicates that the role of dioxygen is not the source of electrochemically generated H2O2. Furthermore, the epoxide 10 was not

Switching the reaction pathways of electrochemically generated β-haloalkoxysulfonium ions – synthesis of halohydrins and epoxides

• Akihiro Shimizu,
• Ryutaro Hayashi,
• Yosuke Ashikari,
• Toshiki Nokami and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2015, 11, 242–248, doi:10.3762/bjoc.11.27

• -I was synthesized using I2 and H2O2; see Supporting Information File 1) indicated that the addition of I+ and DMSO across the C–C double bond was anti-selective as anticipated. Synthesis of halohydrins and epoxides from various alkenes The present method was successfully applied to the synthesis of

Electrochemical selenium- and iodonium-initiated cyclisation of hydroxy-functionalised 1,4-dienes

• Philipp Röse,
• Steffen Emge,
• Jun-ichi Yoshida and
• Gerhard Hilt

Beilstein J. Org. Chem. 2015, 11, 174–183, doi:10.3762/bjoc.11.18

• (IV), mCPBA, FeCl3 or H2O2 have been reported [40][41][42][43][44][45]. A more efficient and versatile method is the electrochemical generation of halonium ions. Thereby, it is possible to accumulate the halonium ions in solution and to add those to a substrate in a separated process (“pool” method

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

• -immobilized manganese phthalocyanine/H2O2aq [166], a Ni(II) complex/H2O2aq [167], and ZnBr2/H2O2 [168]. The oxidative C–O coupling of aromatic aldehydes 181 with cycloalkanes 182 was accomplished in the presence of the Cu(OAc)2/t-BuOOH system to prepare products 183. This reaction is unusual in that it

Multicomponent versus domino reactions: One-pot free-radical synthesis of β-amino-ethers and β-amino-alcohols

• Bianca Rossi,
• Nadia Pastori,
• Simona Prosperini and
• Carlo Punta

Beilstein J. Org. Chem. 2015, 11, 66–73, doi:10.3762/bjoc.11.10

• aldehyde or ketone, and a suitable source of nucleophilic radicals (Nu–H = formamide [24][25], methanol [26][27], ethers [28]), in the presence of titanium chlorides, and slowly dropping a solution of hydroperoxide (H2O2 or tert-butyl hydroperoxide (t-BuOOH)) into the reaction medium (Scheme 1). Aqueous

Preparation of neuroprotective condensed 1,4-benzoxazepines by regio- and diastereoselective domino Knoevenagel–[1,5]-hydride shift cyclization reaction

• László Tóth,
• Yan Fu,
• Hai Yan Zhang,
• Attila Mándi,
• Katalin E. Kövér,
• Tünde-Zita Illyés,
• Attila Kiss-Szikszai,
• Balázs Balogh,
• Tibor Kurtán,
• Sándor Antus and
• Péter Mátyus

Beilstein J. Org. Chem. 2014, 10, 2594–2602, doi:10.3762/bjoc.10.272

• . Separated enantiomers of the products were characterized by HPLC-ECD data, which allowed their configurational assignment on the basis of TDDFT-ECD calculation of the solution conformers. Two compounds showed neuroprotective activities against hydrogen peroxide (H2O2) or β-amyloid25–35 (Aβ25–35)-induced

• preparation of condensed O,N-heterocycles with the 1,2,8,9-tetrahydro-7bH-quinolino[1,2-d][1,4]benzoxazepine skeleton, the neuroprotective activities of which were tested against hydrogen peroxide (H2O2), Alzheimer's amyloid β-peptide fragment Aβ25–35 and oxygen–glucose deprivation (OGD)-induced neurotoxicity

• rac-5 were tested against hydrogen peroxide (H2O2), β-amyloid-25-35 (Aβ25–35) and oxygen–glucose deprivation (OGD)-induced neurotoxicity in human neuroblastoma SH-SY5Y cells [22]. The preliminary screenings showed that rac-7a at 10 µM concentration displayed neuroprotective activity against H2O2

Oligomerization of optically active N-(4-hydroxyphenyl)mandelamide in the presence of β-cyclodextrin and the minor role of chirality

• Helmut Ritter,
• Antonia Stöhr and
• Philippe Favresse

Beilstein J. Org. Chem. 2014, 10, 2361–2366, doi:10.3762/bjoc.10.246

• monomeric residual of each oligomerization was measured twice. The obtained enantiomeric excess (ee) values of the monomeric residual are given in Table 1. Because of the rapid conversion of the monomer 1 during the oligomerization with highly active peroxidase–H2O2 system at room temperature, the reaction

Indium-mediated allylation in carbohydrate synthesis: A short and efficient approach towards higher 2-acetamido-2-deoxy sugars

• Christopher Albler,
• Ralph Hollaus,
• Hanspeter Kählig and
• Walther Schmid

Beilstein J. Org. Chem. 2014, 10, 2230–2234, doi:10.3762/bjoc.10.231

• , rt, 16 h, then TEA, rt, 30–50 min, quant.; (c) H2O2, cat., CH2Cl2, −20 °C, 16 h, then Ph3P(CHCO2Me), CH2Cl2, rt, 1 h, 72–75%, 2 steps; (d) TMSN3, Pd(PPh3)4, THF, rt, 1 h, 76–85%. Deprotection sequence; reagents and conditions: (a): HCl/MeOH, rt, 16–24 h, then MeOH, CH2Cl2, O3, −78 °C then PPh3, rt

Rasta resin–triphenylphosphine oxides and their use as recyclable heterogeneous reagent precursors in halogenation reactions

• Xuanshu Xia and
• Patrick H. Toy

Beilstein J. Org. Chem. 2014, 10, 1397–1405, doi:10.3762/bjoc.10.143

• alcohol, aziridine, aldehyde and epoxide halogenation reactions from which the desired products are easily isolated and the phosphine oxide byproduct is readily recycled. Results and Discussion Rasta resin 16 was prepared by oxidation of 14, which was prepared as previously reported [28], using H2O2

• 1.06 mmol/g, respectively. It should be noted that a test reaction between N,N-diisopropylbenzylamine and H2O2 under similar reaction conditions does not result in amine oxidation, and this seems to indicate that only the phosphine groups of 19 are oxidized during its conversion to 18. Having

Molecular recognition of surface-immobilized carbohydrates by a synthetic lectin

• Melanie Rauschenberg,
• Eva-Corrina Fritz,
• Christian Schulz,
• Tobias Kaufmann and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2014, 10, 1354–1364, doi:10.3762/bjoc.10.138

• small pieces of around 1.6 × 2.6 cm2, cleaned with detergent and dried. After sonification in pentane, acetone and Milli-Q water, the slides were put into a freshly prepared piranha solution (H2O2/H2SO4 = 1:3) for 30 min. The wafers were then thoroughly washed with water, dried and immersed in a 0.3 vol

Stereoselective synthesis of carbocyclic analogues of the nucleoside Q precursor (PreQ₀)

• Sabin Llona-Minguez and
• Simon P. Mackay

Beilstein J. Org. Chem. 2014, 10, 1333–1338, doi:10.3762/bjoc.10.135

• , H2O/THF/AcOH, 3 days, 60 °C, 98%; (b) K-Selectride, THF, 2 h, −90 °C; then KOH (aq), H2O2, 30 min, rt, 80%, 99% ds; (c) LiAlH4, Et2O, 1,5 h, 0 °C to rt; then NaOH (aq), 30 min, rt, 76%, 97% ds (d) MsCl, Et3N, THF, 16 h, rt, (trans- 67%, cis- 64%); (d) NaN3, DMF, 2 days, 80 °C, (trans- 56%, cis- 67

End-group-functionalized poly(N,N-diethylacrylamide) via free-radical chain transfer polymerization: Influence of sulfur oxidation and cyclodextrin on self-organization and cloud points in water

• Sebastian Reinelt,
• Daniel Steinke and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 680–691, doi:10.3762/bjoc.10.61

• ): Influence of RAMEB-CD and oxidation with H2O2. Number averaged hydrodynamic diameters of the polymers and the supramolecular complexes with RAMEB-CD in water at 10 °C. Supporting Information A full experimental section can be found in the Supporting Information. Description of the materials

Synthesis of new enantiopure poly(hydroxy)aminooxepanes as building blocks for multivalent carbohydrate mimetics

• Léa Bouché,
• Maja Kandziora and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 213–223, doi:10.3762/bjoc.10.17

• by Lewis acid-induced rearrangement of 3,6-dihydro-2H-1,2-oxazines B. [TBS = tert-butyldimethylsilyl, TMSE = 2-(trimethylsilyl)ethyl] Synthesis of (Z)-nitrone 3. Conditions: a) 1. p-Bromobenzaldehyde dimethylacetal, TFA, DMF, rt, 5 d; 2. 30% H2O2, K2CO3, H2O, 0 → 20 °C, 16 h; 3. EtI, MeCN, reflux, 20

Synthesis of the B-seco limonoid core scaffold

• Hanna Bruss,
• Hannah Schuster,
• Rémi Martinez,
• Markus Kaiser,
• Andrey P. Antonchick and
• Herbert Waldmann

Beilstein J. Org. Chem. 2014, 10, 194–208, doi:10.3762/bjoc.10.15

• (OAc)2, DMSO, O2, overnight, 72% (3 steps); j) LDA, 1H-benzotriazole-1-methanol, THF, −78 °C, 3 h, 67%, de = 100%; k) TBSCl, imidazole, DMF, rt, overnight, 90%; l) H2O2, NaOH, MeOH, 0 °C, 1 h, 80%, de = 100%; m) NaBH4, (PhSe)2, EtOH, 0 °C to rt, 10 min, 93%; n) TESCl, imidazole, DMF, 40 °C, 2 h, 99%; o

Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

• Alexander O. Terent'ev,
• Dmitry A. Borisov,
• Vera A. Vil’ and
• Valery M. Dembitsky

Beilstein J. Org. Chem. 2014, 10, 34–114, doi:10.3762/bjoc.10.6

• hydroperoxy acetals 61a,b (Scheme 19) [250]. The ozonolysis of 9-methyleneheptadecane-7,11-diyl-bis(methanesulfonate) (63) gave 9-oxoheptadecane-7,11-diyl-bis(methanesulfonate) (64). The latter reacted with H2O2 in the presence of sulfuric acid (or iodine) as the catalyst to form 9,9-dihydroperoxyheptadecane

• ) from 2-(3,5,5-trimethyl-1,2-dioxolan-3-yl)acetic acid (151) (Scheme 37) [267]. Dioxolane 155 that contains a free hydroxy group was synthesized by the oxidative desilylation of silicon-containing peroxide 124 with n-Bu4NF and H2O2 (Scheme 38) [259]. Dioxolane 158 with the aminoquinoline antimalarial

• H2O2–H2NCONH2 complex. More recently, it was shown that in some cases, cheaper catalysts such as p-toluenesulfonic and 10-camphorsulfonic acid can be used for this purpose (Table 17). It was found that cesium hydroxide can be used as a base for the cyclization to give 232 and 234. Compared to Scheme 65

Recent advances in transition metal-catalyzed Csp²-monofluoro-, difluoro-, perfluoromethylation and trifluoromethylthiolation

• Grégory Landelle,
• Armen Panossian,
• Sergiy Pazenok,
• Jean-Pierre Vors and
• Frédéric R. Leroux

Beilstein J. Org. Chem. 2013, 9, 2476–2536, doi:10.3762/bjoc.9.287

• operating. 3.3.4 Fe-catalyzed perfluoroalkylation of Csp2–H bonds. In this section, all the studies that we will discuss used substoichiometric amounts of Fenton’s reagent (FeSO4/H2O2) for the generation of perfluoroalkyl radicals. Complementary work was carried out by E. Baciocchi et al. [112] and by F

Flexible synthesis of anthracycline aglycone mimics via domino carbopalladation reactions

• Markus Leibeling and
• Daniel B. Werz

Beilstein J. Org. Chem. 2013, 9, 2194–2201, doi:10.3762/bjoc.9.258

• desilylated product in 90% yield under oxidative reaction conditions (KHCO3, H2O2, KF in THF and MeOH), i.e., both silyl ether and terminal silane were cleaved. However, it was not possible to utilize this procedure for compound 13a. Under these conditions, the silyl ether was cleaved without touching the

Stereoselective synthesis of the C79–C97 fragment of symbiodinolide

• Hiroyoshi Takamura,
• Takayuki Fujiwara,
• Isao Kadota and
• Daisuke Uemura

Beilstein J. Org. Chem. 2013, 9, 1931–1935, doi:10.3762/bjoc.9.228

• (Scheme 4). The synthesis started from commercially available methyl (S)-3-hydroxy-2-methylpropanoate (21), which was converted to alcohol 22 by the known method [22]. Alcohol 22 was treated with 1-phenyl-1H-tetrazole-5-thiol/DEAD/PPh3 to furnish the corresponding PT-sulfide, which was oxidized with H2O2

A practical synthesis of long-chain iso-fatty acids (iso-C₁₂–C₁₉) and related natural products

• Mark B. Richardson and
• Spencer J. Williams

Beilstein J. Org. Chem. 2013, 9, 1807–1812, doi:10.3762/bjoc.9.210

• a single diastereoisomer (as determined by 1H NMR) in 80% yield. Cleavage of the chiral auxiliary using LiOH/H2O2 (which occurs without racemization at the α-position) [64] afforded (S)-2,15-dimethylpalmitic acid (30) in 98% yield. 2-Hydroxy-15-methylpalmitic acid has been identified from a range of

• ). Reagents and conditions: (a) MeMgBr, THF, 98%; (b) BF3·Et2O, Et3SiH, CH2Cl2, 99%; (c) KMnO4, Bu4NBr, AcOH, H2O, 88% for 1, 96% for 2; (d) i) I2, NaBH4, THF, ii) H2O2, 95%; (e) MsCl, Et3N, CH2Cl2, 98%; (f) KCN, DMSO, THF, 72%; (g) aq NaOH, EtOH, 96%. Synthesis of iso-C15 4, iso-C16 5, and iso-C17 6 fatty

• -fatty acids 30 and 32, and (B) the ketone 33. Reagents and conditions: (a) Et3N, PivCl, LiCl, DMAP, (S)-4-benzyloxazolidinone, 71%; (b) NaHMDS, MeI, THF, 80%; (c) LiOH, H2O2, THF, H2O, 98%; (d) NaHMDS, Davis oxaziridine, THF, 71%; (e) i) iPrMgCl, MeOH, 76%, ii) NaOH, MeOH, 83%; (f) O2, PdCl2, DMA, H2O

Iron-catalyzed decarboxylative alkenylation of cycloalkanes with arylvinyl carboxylic acids via a radical process

• Jincan Zhao,
• Hong Fang,
• Jianlin Han and
• Yi Pan

Beilstein J. Org. Chem. 2013, 9, 1718–1723, doi:10.3762/bjoc.9.197

• , Fe2O3 and Fe3O4 tested (Table 1, entries 4–8). Application of other oxidants such as K2S2O8, H2O2 (30% aqueous solution) or TBPB did not afford any improvements (Table 1, entries 9–11). A decreased loading of Fe(acac)3 to 10 mol % or an increased amount of DTBP to 5.0 equiv and a lower temperature (110