Interaction of cyclodextrins with pyrene-modified polyacrylamide in a mixed solvent of water and dimethyl sulfoxide as studied by steady-state fluorescence

• Akihito Hashidzume,
• Yongtai Zheng and
• Akira Harada

Beilstein J. Org. Chem. 2012, 8, 1312–1317, doi:10.3762/bjoc.8.150

• Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan 10.3762/bjoc.8.150 Abstract The interaction of β- and γ-cyclodextrins (β-CD and γ-CD, respectively) with polyacrylamide modified with pyrenyl (Py) residues (pAAmPy) was investigated in a mixed solvent of water and dimethyl sulfoxide (DMSO) by steady-state

• ][36]. Recently, we have demonstrated this selectivity switching on macroscopic molecular recognition for polyacrylamide-based gels carrying pyrenyl (Py) and CD residues, by changing the composition of a mixed solvent of water and dimethyl sulfoxide (DMSO) [37]. In the present study, the interaction of

Cyclodextrin nanosponge-sensitized enantiodifferentiating photoisomerization of cyclooctene and 1,3-cyclooctadiene

• Wenting Liang,
• Cheng Yang,
• Masaki Nishijima,
• Gaku Fukuhara,
• Tadashi Mori,
• Andrea Mele,
• Franca Castiglione,
• Fabrizio Caldera,
• Francesco Trotta and
• Yoshihisa Inoue

Beilstein J. Org. Chem. 2012, 8, 1305–1311, doi:10.3762/bjoc.8.149

• very low temperatures (below −100 °C). Results and Discussion CDNSs 3, 4 and 5 were prepared in almost quantitative yields by reacting pyromellitic dianhydride (PDA) with β-CD or γ-CD in the presence of triethylamine in dimethyl sulfoxide at room temperature (Scheme 1) and purified by extensive Soxhlet

Control over molecular motion using the cis–trans photoisomerization of the azo group

• Estíbaliz Merino and
• María Ribagorda

Beilstein J. Org. Chem. 2012, 8, 1071–1090, doi:10.3762/bjoc.8.119

• arylhydrazines 18 [134]. In both cases, the sulfoxide group preferentially adopts a rigid S-cis conformation [135], situating the sulfinylic oxygen in 1,3-parallel arrangement with the neighbouring hydrogen (blue arrow, Scheme 1). This arrangement is essential to force a specific final conformation of the

• standard techniques (UV–vis, circular dichroism, chiral HPLC and NMR) has established that the chiral optical response differs greatly depending on the position of the sulfoxide group (C-2 or C-3). Cis isomers in both p-tolylsulfinyl azocompounds show an opposite arrangement of substituents around the N=N

• group, with an S-shaped structure for cis-20 or a U-shaped structure for cis-21. The conformational rigidity of the chiral sulfinyl group is the key to controlling the directionality of the molecular motion of photoisomerization. Thus, choosing the position of the sulfoxide group in the azobenzene

Intramolecular bridges formed by photoswitchable click amino acids

• Christian Hoppmann,
• Ronald Kühne and
• Michael Beyermann

Beilstein J. Org. Chem. 2012, 8, 884–889, doi:10.3762/bjoc.8.100

• the yield of the intramolecular thiol click reaction increased (Figure 2, data shown for peptide 1). At the highest GSH concentration tested (10 mM), only the intermolecular click product 5 ([M + 2H]2+ = 960.90) was detected as the corresponding sulfoxide of the thioether formed in the crosslinked

Synthesis and characterization of a novel carboxyl group containing (co)polyimide with sulfur in the polymer backbone

• Miroslav Mrsevic,
• David Düsselberg and
• Claudia Staudt

Beilstein J. Org. Chem. 2012, 8, 776–786, doi:10.3762/bjoc.8.88

• solubility in amidic solvents, such as dimethylacetamide (DMAC), dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP), as well as in other non-amidic solvents, such as tetrahydrofuran (THF), dimethyl sulfoxide (DMSO) and acetone. No differences in solubility either between the different (co)polyimides

Alkoxide-induced ring opening of bicyclic 2-vinylcyclobutanones: A convenient synthesis of 2-vinyl-substituted 3-cycloalkene-1-carboxylic acid esters

• Xiufang Ji,
• Zhiming Li,
• Quanrui Wang and
• Andreas Goeke

Beilstein J. Org. Chem. 2012, 8, 650–657, doi:10.3762/bjoc.8.72

• ][7][8]. In this context, α,α-dihalosubstituents, thioketal, sulfoxide, ester or aryl substituents have been reported to facilitate the ring cleavage [6][7][8]. We recently reported a novel metathetic cycloreversion of 7-vinyl and aryl bicyclo[3.2.0]hept-2-en-6-ones giving rise to linear polyene

Synthesis of szentiamide, a depsipeptide from entomopathogenic Xenorhabdus szentirmaii with activity against Plasmodium falciparum

• Friederike I. Nollmann,
• Andrea Dowling,
• Marcel Kaiser,
• Klaus Deckmann,
• Sabine Grösch,
• Richard ffrench-Constant and
• Helge B. Bode

Beilstein J. Org. Chem. 2012, 8, 528–533, doi:10.3762/bjoc.8.60

• cells were treated with increasing concentrations of the compound (10, 50 and 100 µM) or dimethyl sulfoxide. After 24 h, 10 µL of WST-1 reagent was added to each well and the cells were incubated for a further 90–150 min. The formation of the formazan was measured at 450 nm against a reference

Binding of group 15 and group 16 oxides by a concave host containing an isophthalamide unit

• Jens Eckelmann,
• Vittorio Saggiomo,
• Svenja Fischmann and
• Ulrich Lüning

Beilstein J. Org. Chem. 2012, 8, 11–17, doi:10.3762/bjoc.8.2

• the magnitude of the CIS need not be correlated with the binding constants. However, when sulfoxides were added as neutral guests, the relative binding of these guests by 1 and 2 showed drastic differences. Dimethyl sulfoxide (DMSO), methylphenyl sulfoxide (MPSO) and diphenyl sulfoxides (DPSO) induced

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

• characterized. Oxidation of the pyrazole-containing thioether by hydrogen peroxide proceeds selectively to provide a sulfoxide or sulfone, depending on the amount of oxidant used. Oxidation of the benzotriazole derivative by hydrogen peroxide is not selective, and sulfoxide and sulfone form concurrently

• . 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

• through its conversion to sulfoxide or sulfone derivatives. In this report we present the synthesis of pyrazole and benzotriazole thioether ligands and their oxidation to the corresponding sulfoxides and sulfones. Results and Discussion 1-(2-Hydroxyethyl)-3,5-dimethylpyrazole (1), the starting compound

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

• Marcus Baumann,
• Ian R. Baxendale,
• Steven V. Ley and
• Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

Synthesis of glycoconjugate fragments of mycobacterial phosphatidylinositol mannosides and lipomannan

• Benjamin Cao,
• Jonathan M. White and
• Spencer J. Williams

Beilstein J. Org. Chem. 2011, 7, 369–377, doi:10.3762/bjoc.7.47

• arabinan to the penultimate mannose residue of LM, and is subsequently capped with a variety of groups including inositol phosphate, 5-methylthioxylose and its sulfoxide, and short 1,2-mannose oligomers [7]. Studies into the biosynthesis of the PIMs, LM and LAM have been greatly facilitated by the

Exceptionally small supramolecular hydrogelators based on aromatic–aromatic interactions

• Junfeng Shi,
• Yuan Gao,
• Zhimou Yang and
• Bing Xu

Beilstein J. Org. Chem. 2011, 7, 167–172, doi:10.3762/bjoc.7.23

• molecular weight as low as 448.51 g/mol, can form a hydrogel at a concentration as low as 0.2 mM and elucidated the molecular structure of the hydrogel based on the crystal structure of the gelator. During that gelation experiment, dimethyl sulfoxide (DMSO) was required in the gel, however, this might

SbCl₃-catalyzed one-pot synthesis of 4,4′-diaminotriarylmethanes under solvent-free conditions: Synthesis, characterization, and DFT studies

• Ghasem Rezanejade Bardajee

Beilstein J. Org. Chem. 2011, 7, 135–144, doi:10.3762/bjoc.7.19

• and aprotic solvents such as dimethyl sulfoxide, N,N-dimethylformamide, dichloromethane, ethanol, diethyl ether, and n-hexane were examined: The best results were obtained under solvent-free conditions without microwave irradiation. The general route for the synthesis of these compounds is shown in

ROMP-Derived cyclooctene-based monolithic polymeric materials reinforced with inorganic nanoparticles for applications in tissue engineering

• Franziska Weichelt,
• Solvig Lenz,
• Stefanie Tiede,
• Ingrid Reinhardt,
• Bernhard Frerich and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2010, 6, 1199–1205, doi:10.3762/bjoc.6.137

• %) and 2-propanol (99.5%) were obtained from Acros Organics (Germany). NaOH (≥98%), CH3OH (99.8%) and H3PO4 (85%) were obtained from Fluka (Germany). CHCl3 (99.8%), dimethyl sulfoxide (DMSO, 99.9%), tetrahydrofuran (THF, 99.0%) and CH2Cl2 (≥99.8%) were obtained from Merck. Norborn-2-ene (99%) was

Hybrid biofunctional nanostructures as stimuli-responsive catalytic systems

• Gernot U. Marten,
• Thorsten Gelbrich and
• Annette M. Schmidt

Beilstein J. Org. Chem. 2010, 6, 922–931, doi:10.3762/bjoc.6.98

• sulfoxide (DMSO; min. 99.5%, Riedel-de-Haen) was distilled under reduced pressure from calcium hydride and stored under argon and molecular sieve (3A). HEPES buffer was prepared from 11 mM HEPES (Sigma), 140 mM NaCl (Merck), 4 mM KCl (Merck), 10 mM D(+)-glucose, and dissolved in deionized water. 2

Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

• Vladimir N. Boiko

Beilstein J. Org. Chem. 2010, 6, 880–921, doi:10.3762/bjoc.6.88

Recent advances in carbocupration of α-heterosubstituted alkynes

• Ahmad Basheer and
• Ilan Marek

Beilstein J. Org. Chem. 2010, 6, No. 77, doi:10.3762/bjoc.6.77

• sulfoxides 36 in quantitative yields (Scheme 19) [37][38][39][40] that can be further used in organic synthesis [41][42][43]. However, to obtain functionalized dialkylated ethylenic sulfoxide species, the addition of functionalized organozinc species is required. Upon treatment with (FG-R2)2Zn (2 equiv) or

• FG-R2ZnX in the presence of a catalytic amount of CuI (2 mol %), 1-alkynyl sulfoxide 35 undergoes carbozincation to give the functionalized vinylic sulfoxide (Z)-37 in excellent yield. The reaction proceeds in a syn-selective fashion to give only the linear isomer (Scheme 19) [44][45]. The fact that

• pure sulfoxide was used as starting material, no racemization was detected [40]. 1-Alkynyl sulfones 38 are prone to addition of organocopper reagents. However, the stereochemistry of the resulting vinyl sulfones 39 appear to be dependent on the relative amounts of copper(I) bromide as well as the

Shelf-stable electrophilic trifluoromethylating reagents: A brief historical perspective

• Norio Shibata,
• Andrej Matsnev and
• Dominique Cahard

Beilstein J. Org. Chem. 2010, 6, No. 65, doi:10.3762/bjoc.6.65

• electrophilic trifluoromethylation by means of a diaryl(trifluoromethyl)sulfonium salt, Ar2S+CF3 SbF6− (3) [11]. This trifluoromethylating reagent was obtained by treatment of aryltrifluoromethyl sulfoxide 1 with SF3+ SbF6− and subsequent reaction of the fluoro(trifluoromethyl) arylsulfonium salt 2 with

• treating 2-phenoxyphenyl trifluoromethyl sulfoxide with triflic anhydride (Scheme 5). The reaction proceeded very slowly and in low yield (6 days, 26%), presumably because of the stabilization of a cationic sulfur atom in the intermediate by the electron-donating ether moiety [13]. The relative

• , 2-(phenyl)phenyl trifluoromethyl sulfoxide was converted into the corresponding sulfonium salt by treatment with an excess amount of 60% SO3·H2SO4 at 0 °C followed by hydrogen sulfate anion exchange with tetrafluoroborate or triflate ion (Scheme 11). Increasing the reaction temperature during

Free radical homopolymerization of a vinylferrocene/cyclodextrin complex in water

• Helmut Ritter,
• Beate E. Mondrzik,
• Matthias Rehahn and
• Markus Gallei

Beilstein J. Org. Chem. 2010, 6, No. 60, doi:10.3762/bjoc.6.60

• cyclodextrin ring. Experimental Part Materials and Instrumentation Methyl-β-cyclodextrin was obtained from Wacker-Chemie GmbH, Burghausen, Germany, and used after drying overnight with a vacuum oil pump over P4O10. Dimethyl-d6 sulfoxide (99.9 atom % D) was obtained from Euriso-Top SA, France. 2,2-Azobis[2-(2

• ) spectrometer equipped with an ATR unit. The measurements were performed in the range of 4000–300 cm−1 at room temperature. 1H NMR spectra were recorded with a Bruker AC 500 at 20 °C. Chemical shifts were referenced to the solvent value δ 2.51 for dimethyl-d6 sulfoxide. Matrix-assisted laser desorption

Synthesis of bis(3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoyl)(phenyl)phosphine oxide – a tailor-made photoinitiator for dental adhesives

• Norbert Moszner,
• Iris Lamparth,
• Jörg Angermann,
• Urs Karl Fischer,
• Frank Zeuner,
• Thorsten Bock,
• Robert Liska and
• Volker Rheinberger

Beilstein J. Org. Chem. 2010, 6, No. 26, doi:10.3762/bjoc.6.26

• dimethyl sulfoxide-d6 as the solvent using tetramethylsilane (TMS) as standard. A FT-IR spectrometer 1600 (Perkin-Elmer) was used to record IR spectra. Melting points were measured with a Melting Point B-540 (Büchi). Elemental analyses were performed with an elemental analyzer CHNS-O Typ EA 1108 (Fisons

Recognition properties of receptors consisting of imidazole and indole recognition units towards carbohydrates

• Monika Mazik and
• André Hartmann

Beilstein J. Org. Chem. 2010, 6, No. 9, doi:10.3762/bjoc.6.9

• the limitations of the NMR method, see ref. [55]). After the addition of 5% DMSO-d6 the binding constants for 4•6a were determined to be 35000 (K11) and 1000 M−1 (K12). Thus, the affinity of 4 significantly decreases as solvent polarity increases (the addition of dimethyl sulfoxide also caused the

• equiv of 2-amino-4,6-dimethylpyridine, CH3CN/THF, K2CO3, r. t., 3 d (20%); d) potassium phthalimide, dimethyl sulfoxide, 95 °C, 8 h, (57%); e) hydrazine hydrate, ethanol/toluene, reflux, 19.5 h, KOH (43%) [27]; f) 4 equiv of 4(5)-imidazole-carbaldehyde (18), CH3OH, 3 d; g) 4 equiv of 3-indole

Self-association of an indole based guanidinium-carboxylate-zwitterion: formation of stable dimers in solution and the solid state

• Carolin Rether,
• Wilhelm Sicking,
• Roland Boese and
• Carsten Schmuck

Beilstein J. Org. Chem. 2010, 6, No. 3, doi:10.3762/bjoc.6.3

• interact at concentration > ca. 15 mM. However, the exact nature of these larger aggregates is unclear at the moment. We were able to determine the solid state structure of 2. X-ray quality crystals of compound 2 were obtained by slow evaporation of a dimethyl sulfoxide solution. X-ray crystallography

A stable enol from a 6-substituted benzanthrone and its unexpected behaviour under acidic conditions

• Marc Debeaux,
• Kai Brandhorst,
• Peter G. Jones,
• Henning Hopf,
• Jörg Grunenberg,
• Wolfgang Kowalsky and
• Hans-Hermann Johannes

Beilstein J. Org. Chem. 2009, 5, No. 31, doi:10.3762/bjoc.5.31

• stable as a solid and also in deuterated dimethyl sulfoxide, since an NMR solution in this solvent was unchanged after one week. In contrast, a solution of 4 in chloroform showed quantitative conversion to the 6-substituted benzanthrone 7 after approximately one week; a process that was subsequently

Enantiospecific synthesis of [2.2]paracyclophane- 4-thiol and derivatives

• Gareth J. Rowlands and
• Richard J. Seacome

Beilstein J. Org. Chem. 2009, 5, No. 9, doi:10.3762/bjoc.5.9

• describes a simple route to enantiomerically enriched [2.2]paracyclophane-4-thiol via the stereospecific introduction of a chiral sulfoxide to the [2.2]paracyclophane skeleton. The first synthesis of an enantiomerically enriched planar chiral benzothiazole is also reported. Keywords: heterocycle; [2.2

• of enantiomerically pure 4-hydroxy[2.2]paracyclophane or application of our own sulfoxide-metal exchange protocol [31] would permit enantiospecific variants of either route, but neither has been reported. An elegant entry to a variety of racemic alkyl sulfides and sulfoxides by an SEAr reaction

• range of disubstituted derivatives [33]. The basis of the strategy is the stereospecific introduction of a sulfoxide to [2.2]paracyclophane to give readily separable diastereoisomers, thus resolving the planar chirality [34]. The sulfoxide moiety is used to direct further elaboration of the [2.2

Reduction of arenediazonium salts by tetrakis(dimethylamino)ethylene (TDAE): Efficient formation of products derived from aryl radicals

• Mohan Mahesh,
• John A. Murphy,
• Franck LeStrat and
• Hans Peter Wessel

Beilstein J. Org. Chem. 2009, 5, No. 1, doi:10.3762/bjoc.5.1

• the radical chemistry. One way to achieve clean termination of the radical process would be by providing a radical leaving group adjacent to the cyclised radical 19. Appropriate groups might be sulfide, sulfoxide and sulfonyl groups [64][65]. Accordingly, arenediazonium salts 31a–d were prepared

• like a sulfide, sulfoxide or sulfone is necessary for the self-termination of the 5-exo-trig radical cyclization reactions to avoid competing intermolecular radical side-reactions. The TDAE-mediated radical-based addition-elimination route for the construction of indole ring systems warranted anhydrous