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

Polymeric redox-responsive delivery systems bearing ammonium salts cross-linked via disulfides

• Christian Dollendorf,
• Martin Hetzer and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 1652–1662, doi:10.3762/bjoc.9.189

• functionalities was investigated by immersion of 6c (5 mol % CL 1 and 5 mol % CL 2) in aqueous 30% H2O2. In a first attempt, a treatment with KOH and oxygen at 60 °C, after swelling and reduction of the disulfide bonds, the polymer discs lost their stability and were partially destroyed. Therefore, a gentler

• oxidation method was used by immersion of the polymer discs in aqueous 30% H2O2 at room temperature. After three days the sample was subjected to oscillatory measurements again and the value for G’ was compared to the values received after immersion in distilled water and aqueous DTT solution. Although G

• discrepancy to the initial value could be side reactions of excess DTT with cleaved thiol groups and therefore less cross-linkage within the network structure. Another explanation for this observation could be the further oxidation of thiol groups to sulfonic acid by H2O2. Investigations of material

A reductive coupling strategy towards ripostatin A

• Kristin D. Schleicher and
• Timothy F. Jamison

Beilstein J. Org. Chem. 2013, 9, 1533–1550, doi:10.3762/bjoc.9.175

• alternative promoters were investigated to avoid the use of mercury(II) salts in the ketal deprotection (including MeI, H2O2, AgClO4/I2); however, these generally led to concomitant removal of the TBS groups. Ketone 19 was converted to the α,β-unsaturated ester 20 using the Peterson olefination [32

Simple and rapid hydrogenation of p-nitrophenol with aqueous formic acid in catalytic flow reactors

• Rahat Javaid,
• Shin-ichiro Kawasaki,
• Akira Suzuki and
• Toshishige M. Suzuki

Beilstein J. Org. Chem. 2013, 9, 1156–1163, doi:10.3762/bjoc.9.129

• acid (HNO3, 60%) and hydrogen peroxide (H2O2, 30%) were purchased from Wako Pure Chemical Industries Ltd. and were used without further purification. Fabrication of tubular reactors A double-layered tube (o.d. 1.6 mm, i.d. 0.5 mm, length 100 cm) composed of Inconel 625 and titanium (Ti) inner layer

• (thickness 120 μm) was fabricated by E.S.Q. Co., Japan, by elongation of the titanium inlaid Inconel 625 piece by stretch-draw process, and used as the reactor support [11]. The Ti inner surface was oxidized to TiO2 with H2O2 under supercritical water conditions (450 °C, 30 MPa). The TiO2 surface, which is

Synthesis of the tetracyclic core of Illicium sesquiterpenes using an organocatalyzed asymmetric Robinson annulation

• Lynnie Trzoss,
• Jing Xu,
• Michelle H. Lacoske and
• Emmanuel A. Theodorakis

Beilstein J. Org. Chem. 2013, 9, 1135–1140, doi:10.3762/bjoc.9.126

• (0)-catalyzed carbomethoxylation [87][88][89][90] produced the desired C-ring lactone 20 in 61% yield. Epoxidation of the C-6/C-7 enone with NaOH/H2O2 followed by oxidative cleavage of the C-11 terminal alkene under OsO4/NaIO4 conditions [91][92] afforded the corresponding C-11 aldehyde. Exposure of

NHC-catalysed highly selective aerobic oxidation of nonactivated aldehydes

• Lennart Möhlmann,
• Stefan Ludwig and
• Siegfried Blechert

Beilstein J. Org. Chem. 2013, 9, 602–607, doi:10.3762/bjoc.9.65

• H2O2 as the terminal oxidation agent instead of O2 under nitrogen atmosphere was carried out for the NHC-catalysed oxidation of 4-nitrobenzaldehyde to 4-nitrobenzoic acid. It revealed that the peroxide was capable of effecting the oxidation as well providing comparable conversion. Conclusion In summary

New enzymatically polymerized copolymers from 4-tert-butylphenol and 4-ferrocenylphenol and their modification and inclusion complexes with β-cyclodextrin

• Adam Mondrzyk,
• Beate Mondrzik,
• Sabrina Gingter and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 2118–2123, doi:10.3762/bjoc.8.238

• of a copolymer of 4-tert-butylphenol and 4-ferrocenylphenol by horse radish peroxidase (HRP) in the presence of H2O2 in a 1,4-dioxane/water system is described. Furthermore, polymer-analogous alkylation of the free hydroxy groups and subsequent click reaction with mono-6-azido-6-desoxy-β-cyclodextrin

• ][25][26][27][28][29][30]. Results and Discussion 4-Ferrocenylphenol (2) was prepared according to the literature [31], in high purity (Scheme 1). It was then enzymatically copolymerized with 4-tert-butylphenol (3) in the presence of HRP and H2O2. The resulting copolymer 4 with a weight-average

• copolymerization of 4-ferrocenylphenol with 4-tert-butylphenol. The 4-ferrocenylphenol obviously tolerates the oxidative environment of H2O2. Furthermore, ortho–ortho- and oxy-ortho-connected phenol monomers were found. However, the free hydroxy groups were subjected to alkylation with propargyl bromide and

Peptides presenting the binding site of human CD4 for the HIV-1 envelope glycoprotein gp120

• Julia Meier,
• Kristin Kassler,
• Heinrich Sticht and
• Jutta Eichler

Beilstein J. Org. Chem. 2012, 8, 1858–1866, doi:10.3762/bjoc.8.214

• peroxidase conjugate from Dianova (diluted 1:5000 with antibody buffer), and washed four times with washing buffer. Plates were developed with 100 µL/well substrate solution (1 mg/mL OPD in 0.03% H2O2/H2O) in the dark (approx. 20 min), and the reaction was stopped by addition of 2 M sulfuric acid (50 µL/well

Stereoselective synthesis of trans-fused iridoid lactones and their identification in the parasitoid wasp Alloxysta victrix, Part I: Dihydronepetalactones

• Nicole Zimmermann,
• Robert Hilgraf,
• Lutz Lehmann,
• Daniel Ibarra and
• Wittko Francke

Beilstein J. Org. Chem. 2012, 8, 1246–1255, doi:10.3762/bjoc.8.140

• ) MeOH/HCl, rt, 96 h (82%); d) 2,6-lutidine, reflux, 72 h (75% of 12 + 13); e) BH3·SMe2, 0 °C, THF, NaOH, H2O2 (86% mixture of diastereomers); f) p-TsOH, toluene, reflux (17% of a + b). Synthesis of the key compound 16. Reaction conditions: a) O3, MeOH, −50 °C (86%); b) AcOH, piperidine, C6H6, reflux (85

• %); c) LiAlH4, Et2O (82%); d) Ac2O, pyridine, rt (91%); e) B2H6, 2-methyl-2-butene, 0 °C, THF, NaOH, H2O2 (66%). Synthesis of trans,trans-substituted dihydronepetalactone b. Reaction conditions: a) TBDMSCl, imidazole, DMF, 0 °C (99%); b) KOH, MeOH, 0 °C (87%); c) PDC, MS, CH2Cl2, 0 °C to rt (61%); d

Multistep organic synthesis of modular photosystems

• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2012, 8, 897–904, doi:10.3762/bjoc.8.102

• , that is, a boiling 5:1:1 mixture of water, 24% NH4OH and 30% H2O2, and then rinsed with bidistilled water and EtOH, and dried. Then the ITO was immersed in a 3 mM solution of initiator 2 in DMSO for 2 days. The formation of monolayers of 48 on ITO electrodes was followed by the inhibition of potassium

An easily accessible sulfated saccharide mimetic inhibits in vitro human tumor cell adhesion and angiogenesis of vascular endothelial cells

• Grazia Marano,
• Claas Gronewold,
• Martin Frank,
• Anette Merling,
• Christian Kliem,
• Sandra Sauer,
• Manfred Wiessler,
• Eva Frei and
• Reinhard Schwartz-Albiez

Beilstein J. Org. Chem. 2012, 8, 787–803, doi:10.3762/bjoc.8.89

Triterpenoid saponins from the roots of Acanthophyllum gypsophiloides Regel

• Elena A. Khatuntseva,
• Vladimir M. Men’shov,
• Alexander S. Shashkov,
• Yury E. Tsvetkov,
• Rodion N. Stepanenko,
• Raymonda Ya. Vlasenko,
• Elvira E. Shults,
• Genrikh A. Tolstikov,
• Tatjana G. Tolstikova,
• Dimitri S. Baev,
• Vasiliy A. Kaledin,
• Nelli A. Popova,
• Valeriy P. Nikolin,
• Pavel P. Laktionov,
• Anna V. Cherepanova,
• Tatiana V. Kulakovskaya,
• Ekaterina V. Kulakovskaya and
• Nikolay E. Nifantiev

Beilstein J. Org. Chem. 2012, 8, 763–775, doi:10.3762/bjoc.8.87

• washed, and substrate (o-phenylenediamine, 0.4 mg/mL in 0.1 M phosphate-citrate buffer with 0.0013% H2O2) was added to each well. Plates were then incubated for 25 min at 37 °C, after which the reaction was terminated by adding 50 μL per well of 2 N H2SO4. The optical density (OD) was measured in an

Carbohydrate-auxiliary assisted preparation of enantiopure 1,2-oxazine derivatives and aminopolyols

• Marcin Jasiński,
• Dieter Lentz and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2012, 8, 662–674, doi:10.3762/bjoc.8.74

• ) was added at −30 °C. The solution was warmed to room temperature and stirred for 3 h, then cooled to −10 °C and an aq NaOH solution (2 M, 4.8 mL) followed by H2O2 (30%, 1.6 mL) were added. Stirring at room temperature was continued overnight. After addition of a sat. aq Na2S2O3 solution, the layers

• protocol; (a) BH3·THF (4.0 equiv), THF, −30 °C to rt, 3 h; (b) NaOH, H2O2 (30%), −10 °C to rt, overnight. Samarium diiodide-induced ring opening of tetrahydro-2H-1,2-oxazine derivatives 12 and 13. Reaction of tetrahydro-2H-1,2-oxazine 18 with samarium diiodide. (a) NaH (1.4 equiv), BnBr (1.2 equiv), DMF, 0

Efficient oxidation of oleanolic acid derivatives using magnesium bis(monoperoxyphthalate) hexahydrate (MMPP): A convenient 2-step procedure towards 12-oxo-28-carboxylic acid derivatives

• Jorge A. R. Salvador,
• Vânia M. Moreira,
• Rui M. A. Pinto,
• Ana S. Leal and
• José A. Paixão

Beilstein J. Org. Chem. 2012, 8, 164–169, doi:10.3762/bjoc.8.17

• ][24], but weak selectivity and low isolated yields were observed. Alternatively, oxidation reagents such as H2O2 in acetic acid [25][26], the inorganic salt mixture KMnO4/CuSO4 [27], ozone [15][28][29] and m-chloroperoxybenzoic acid (mCPBA) [30][31] have also been reported. Magnesium bis

Synthesis and oxidation of some azole-containing thioethers

• Andrei S. Potapov,
• Nina P. Chernova,
• Vladimir D. Ogorodnikov,
• Tatiana V. Petrenko and
• Andrei I. Khlebnikov

Beilstein J. Org. Chem. 2011, 7, 1526–1532, doi:10.3762/bjoc.7.179

• . Selenium dioxide-catalyzed oxidation of benzotriazole thioether by H2O2, however, proceeds selectively and yields sulfoxide only. Keywords: azole; oxidation; sulfone; sulfoxide; thioether; Introduction Compounds comprising two pyrazole moieties linked by an aliphatic spacer act as bidentate chelating

• was isolated, even after 96 h at room temperature. Increasing the quantity of H2O2 to 1.5 equiv resulted in the formation of sulfoxide 8, but full conversion of the starting material could not be achieved (Table 1, entry 1). Raising the temperature to 60 °C led to a considerable increase in the

• reaction rate and a comparable conversion was achieved in 6 h (Table 1, entry 2). Despite the use of a stoichiometric amount of H2O2, oxidation of thioether 5 or sulfoxide 8 proceeds concurrently, and a small quantity of sulfone 9 was detected in the reaction mixture. Therefore, further increase of the

Coupled chemo(enzymatic) reactions in continuous flow

• Ruslan Yuryev,
• Simon Strompen and
• Andreas Liese

Beilstein J. Org. Chem. 2011, 7, 1449–1467, doi:10.3762/bjoc.7.169

• ). The coupled reaction is carried out in a continuously operated packed-bed microreactor. As compared to the batch-mode experiments, higher concentrations of H2O2 were applied without detectable catalyst deactivation after 24 hours. At 100% conversion, a space-time yield of 646 g L−1 day−1 was obtained

• scavenger column containing a sulfonic acid resin. The H2O2-mediated oxidative dimerization and intramolecular cyclization of 51 to the product 52 was catalyzed by an immobilized peroxidase enzyme packed into the last column. The authors validated the design of the flow reactor by synthesizing gram

• of nitrobenzene (53) by zinc to hydroxyaminobenzene (HAB, 54), which in the second HAB-mutase-catalyzed step is rearranged intramolecularly to form 2-aminophenol (55) (Scheme 16). The final transformation involves the oxidation of 55 to 2-aminophenoxazin-3-one (56) by H2O2, catalyzed by soybean

Synthesis of 5-(6-hydroxy-7H-purine-8-ylthio)- 2-(N-hydroxyformamido)pentanoic acid

• Yanmei Zhang,
• Greg Elliot,
• Adrian Saldanha,
• Igor Tsigelny,
• Dennis Carson and
• Wolf Wrasidlo

Beilstein J. Org. Chem. 2010, 6, 742–747, doi:10.3762/bjoc.6.93

• °C. The reaction mixture was warmed to room temperature. After stirring at this temperature for 23 h, the reaction mixture was cooled to 0 °C. 3 M NaOAc (3.43 mL) and 30% H2O2 (1.71 mL) were added successively. The mixture was heated and stirred at 50 °C for 4 h. After cooling to room temperature