Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

• Barry M. Trost,
• Michael C. Ryan and
• Meera Rao

Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110

• (CpRu) complexes containing tethered chiral sulfoxides were synthesized via an oxidative [3 + 2] cycloaddition reaction between an alkyne and an allylruthenium complex. Sulfoxide complex 1 containing a p-anisole moiety on its sulfoxide proved to be the most efficient and selective catalyst for the

• alcohols revealed a matched/mismatched effect that was strongly dependent on the nature of the solvent. Keywords: asymmetric catalysis; [3.1.0] bicycles; [4.1.0] bicycles; cycloisomerization; 1,6-enyne; 1,7-enyne; ruthenium catalysis; sulfoxide; Introduction Due to their prevalence in natural products [1

• ] cycloaddition to form a ruthenacyclobutane, and reductively eliminates to generate the bicyclic product. Intrigued by the possibility of rendering this reaction asymmetric, we wondered if an appropriate choice of catalyst, namely the chiral CpRu-sulfoxide catalysts 1 our group developed for asymmetric allylic

Interactions of cyclodextrins and their derivatives with toxic organophosphorus compounds

• Sophie Letort,
• Sébastien Balieu,
• William Erb,
• Géraldine Gouhier and
• François Estour

Beilstein J. Org. Chem. 2016, 12, 204–228, doi:10.3762/bjoc.12.23

• (versus equivalents of CD and the halogenated derivative) were evaluated in dimethyl sulfoxide. As expected, halogenobenzylic derivatives 25a–d gave the best yields compared to those obtained with methyl bromopropyliodobenzoates 25e–f. The hydroxy groups of compounds 25b–d were also methylated (compounds

Physical properties and biological activities of hesperetin and naringenin in complex with methylated β-cyclodextrin

• Waratchada Sangpheak,
• Jintawee Kicuntod,
• Roswitha Schuster,
• Thanyada Rungrotmongkol,
• Peter Wolschann,
• Nawee Kungwan,
• Helmut Viernstein,
• Monika Mueller and
• Piamsook Pongsawasdi

Beilstein J. Org. Chem. 2015, 11, 2763–2773, doi:10.3762/bjoc.11.297

• lines. Complexation mostly leads to a slightly increased effect. Experimental Materials Hesperetin was purchased from Cayman Chemicals (Ann Arbor, MI, USA) and β-CD and RAMEB were purchased from Wako Pure Chemical Industries (Osaka, Japan), respectively. Naringenin, DM-β-CD, dimethyl sulfoxide (DMSO

Synthesis and photophysical characteristics of polyfluorene polyrotaxanes

• Aurica Farcas,
• Giulia Tregnago,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert and
• Franco Cacialli

Beilstein J. Org. Chem. 2015, 11, 2677–2688, doi:10.3762/bjoc.11.288

• the generation of active layers in organic electronic devices. Experimental Materials and methods 1, 2, tetrakis(triphenylphosphine)palladium(0) [Pd(PPh3)4], β- and γCD, bromobenzene (Br–Ph), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and quinine sulfate dehydrate in 0.5 M sulfuric acid were

Assembly of synthetic Aβ miniamyloids on polyol templates

• Sebastian Nils Fischer and
• Armin Geyer

Beilstein J. Org. Chem. 2015, 11, 2646–2653, doi:10.3762/bjoc.11.284

• meso-erythritol with a peptide boronic acid is complete in dimethyl sulfoxide, but a nearly equimolar mixture of the regioisomeric 5- and 6-membered ester is obtained. The CH and CH2 protons of the polyol and the CHα overlap between 4 and 5 ppm in the 1H NMR, however, they are well separated in a CH

Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

• Tatjana Huber,
• Lara Weisheit and
• Thomas Magauer

Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273

• for the key intramolecular acyl transfer reaction to form the cyclononene motif. After sodium periodate oxidation of sulfide 56 to the corresponding sulfoxide, addition of lithium diisopropylamide initiated the intramolecular acyl transfer and led to formation of cyclononene 57 in quantitative yield

Cholesterol lowering effects of mono-lactose-appended β-cyclodextrin in Niemann–Pick type C disease-like HepG2 cells

• Keiichi Motoyama,
• Yumi Hirai,
• Rena Nishiyama,
• Yuki Maeda,
• Taishi Higashi,
• Yoichi Ishitsuka,
• Yuki Kondo,
• Tetsumi Irie,
• Takumi Era and
• Hidetoshi Arima

Beilstein J. Org. Chem. 2015, 11, 2079–2086, doi:10.3762/bjoc.11.224

• , lactose was modified to NH2-β-CyD using the reducing agent cyanotrihydroborate in dimethyl sulfoxide (DMSO) at room temperature for 24 h. No unreacted free lactose was confirmed by thin-layer chromatography (TLC). The MALDI–TOF MS spectrum of Lac-β-CyD showed a peak at m/z 1483 derived from lactose mono

A comprehensive study of olefin metathesis catalyzed by Ru-based catalysts

• Albert Poater and
• Luigi Cavallo

Beilstein J. Org. Chem. 2015, 11, 1767–1780, doi:10.3762/bjoc.11.192

• formed by chelation of the sulfoxide ligand in 12 allows for a trans O–Ru–O geometry with little steric strain. 12 presents three cis isomers, denoted as C(S1), C(S2), and C(O) in Table 2, which correspond to have the phenolic or the sulfonic O atom trans to the NHC ligand (see Figure 1). Our

Qualitative evaluation of regioselectivity in the formation of di- and tri-6-O-tritylates of α-cyclodextrin

• Keisuke Yoshikiyo,
• Yoshihisa Matsui and
• Tatsuyuki Yamamoto

Beilstein J. Org. Chem. 2015, 11, 1530–1540, doi:10.3762/bjoc.11.168

• 13C NMR spectra (Figure 3a, b, and c, respectively) in dimethyl sulfoxide-d6 (DMSO-d6) at 50 °C. Tanimoto, et al. [13], have already reported the 13C NMR spectra of the isomers measured in C5D5N. On the basis of a comparison of their spectra with ours, we assigned that the isomers which gave the first

Tetrathiafulvalene-based azine ligands for anion and metal cation coordination

• Awatef Ayadi,
• Aziz El Alamy,
• Olivier Alévêque,
• Magali Allain,
• Nabil Zouari,
• Mohammed Bouachrine and
• Abdelkrim El-Ghayoury

Beilstein J. Org. Chem. 2015, 11, 1379–1391, doi:10.3762/bjoc.11.149

• contribution corresponding to dimethyl sulfoxide solvent from the intensity data. The assumed solvent composition (3 DMSO per asymmetric unit) was used in the calculation of the empirical formula, formula weight, density, linear absorption coefficient and F(000). For complex 3, the largest difference peak and

Regioselective synthesis of chiral dimethyl-bis(ethylenedithio)tetrathiafulvalene sulfones

• Flavia Pop and
• Narcis Avarvari

Beilstein J. Org. Chem. 2015, 11, 1105–1111, doi:10.3762/bjoc.11.124

• , characterization and solid-state structures of the (S,S) and (R,R) enantiomers of DM-BEDT-TTF monosulfones 1 (Scheme 1). Results and Discussion In our previous studies dealing with the sulfoxidation of the BEDT-TTF donor we could selectively obtain the inner BEDT-TTF sulfoxide (Scheme 1) by using chiral sulfonyl

• -oxaziridines as oxidizing agent [27][28]. However, the inner BEDT-TTF sulfoxide was shown to be of only limited interest as precursor for molecular conductors, since it does not reversibly oxidize into a radical cation. This behavior is due to the moderate kinetic stability of the latter, which releases oxygen

• that the oxidation of the outer sulfur atoms into sulfoxide or sulfone should only moderately influence the oxidation potential and thus provide more stable radical cation species. In order to access chiral precursors with controlled stereochemistry we decided to investigate the sulfoxidation of the DM

Quarternization of 3-azido-1-propyne oligomers obtained by copper(I)-catalyzed azide–alkyne cycloaddition polymerization

• Shun Nakano,
• Akihito Hashidzume and
• Takahiro Sato

Beilstein J. Org. Chem. 2015, 11, 1037–1042, doi:10.3762/bjoc.11.116

• 1H and 13C NMR spectra measured in dimethyl sulfoxide-d6 (DMSO-d6) for the oligomer quarternized (oligoAPMe, run 1 in Table 1). As can be seen in Figure 1a, the 1H NMR spectrum exhibits signals ascribable to the methine proton in 1,2,3-triazole and methylene protons in the polymer backbone in the

Radical-mediated dehydrative preparation of cyclic imides using (NH₄)₂S₂O₈–DMSO: application to the synthesis of vernakalant

• Dnyaneshwar N. Garad,
• Subhash D. Tanpure and
• Santosh B. Mhaske

Beilstein J. Org. Chem. 2015, 11, 1008–1016, doi:10.3762/bjoc.11.113

• Dnyaneshwar N. Garad Subhash D. Tanpure Santosh B. Mhaske CSIR-National Chemical Laboratory, Division of Organic Chemistry, Pune 411 008, India 10.3762/bjoc.11.113 Abstract Ammonium persulfate–dimethyl sulfoxide (APS–DMSO) has been developed as an efficient and new dehydrating reagent for a

Synthesis of 1,2-cis-2-C-branched aryl-C-glucosides via desulfurization of carbohydrate based hemithioacetals

• Henok H. Kinfe,
• Fanuel M. Mebrahtu,
• Mandlenkosi M. Manana,
• Kagiso Madumo and
• Mokela S. Sokamisa

Beilstein J. Org. Chem. 2015, 11, 583–588, doi:10.3762/bjoc.11.64

• hemithioketals are well documented, the desulfurization of the related hemithioacetals (RCH(OH)SR) are less explored [20][21]. In achieving our goals, sulfoxide 2a synthesized from a controlled oxidation of thiochroman 1a was subjected to Pummerer rearrangement followed by Zemplén deacetylation to provide

Hetero-Diels–Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles

• Grzegorz Mlostoń,
• Paulina Grzelak,
• Maciej Mikina,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2015, 11, 576–582, doi:10.3762/bjoc.11.63

• sulfoxide. No attempts were made to isolate this product. The same oxidation protocol was applied to convert thiopyranes 5a, 4b, and 5b into the corresponding sulfones 6b–6d in 94, 70, and 80% yield, respectively. The structure of 6d was established by X-ray single crystal structure determination (Figure 2

• treatment with mCPBA at room temperature to give the corresponding sulfones. In this reaction, even when using equimolar amounts of mCPBA, selective formation of the sulfoxide could not be achieved. The obtained sulfones are promising substrates for thermal SO2 extrusion reactions aimed at the contraction

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

• ions generated by the reaction of electrogenerated Br+ and I+ ions stabilized by dimethyl sulfoxide (DMSO) reacted with sodium hydroxide and sodium methoxide to give the corresponding halohydrins and epoxides, respectively, whereas the treatment with triethylamine gave α-halocarbonyl compounds

• . Recently, we reported that dimethyl sulfoxide (DMSO) can also be used to effectively stabilize halogen cations (Scheme 1) [22]. The pools of stabilized halogen cations enable alkene difunctionalization. We previously reported that the reaction of alkenes with DMSO-stabilized halogen cations such as Br+ and

• . Conclusion In conclusion, we found that the reaction pathways of β-haloalkoxysulfonium ions generated by the reaction of electrogenerated Br+ and I+ stabilized by dimethyl sulfoxide (DMSO) can be switched by changing the nature of the base. The present transformation serves as stereospecific route to

Formulation development, stability and anticancer efficacy of core-shell cyclodextrin nanocapsules for oral chemotherapy with camptothecin

• Hale Ünal,
• Naile Öztürk and
• Erem Bilensoy

Beilstein J. Org. Chem. 2015, 11, 204–212, doi:10.3762/bjoc.11.22

• inactive carboxylate form in physiological or alkaline pH causing the effectiveness of chemotherapy to be reduced or even inhibited [20]. In addition to its stability problem, CPT has a very poor water solubility which is less than 1 µg/mL and is only soluble in dimethyl sulfoxide (DMSO) and mixtures of

Formation of nanoparticles by cooperative inclusion between (S)-camptothecin-modified dextrans and β-cyclodextrin polymers

• Thorbjørn Terndrup Nielsen,
• Catherine Amiel,
• Laurent Duroux,
• Kim Lambertsen Larsen,
• Lars Wagner Städe,
• Reinhard Wimmer and
• Véronique Wintgens

Beilstein J. Org. Chem. 2015, 11, 147–154, doi:10.3762/bjoc.11.14

• -(dimethylamino)pyridine (DMAP) ≥98%, anhydrous dimethyl sulfoxide (DMSO) ≥99.5%, sodium L-ascorbate (NaAsc) ≥98%, tetrakis(acetonitrile)copper(I) hexafluorophosphate (Cu(CH3CN)4PF6) 97% were all from Sigma-Aldrich and were used as received. A β-CD-dextran polymer (D70HPβ-CD) was obtained by grafting 6-azido-O

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

• , vinyl phenyl sulfoxide ligand 234, and Pd(OAc)2 resulted in the selective formation of branched allyl esters 235 [217]. This reaction afforded linear esters 236 as byproducts. Apparently, ligand 234 serves for the formation of the π-allyl–palladium intermediate, and benzoquinone mediates the subsequent

Effects of RAMEA-complexed polyunsaturated fatty acids on the response of human dendritic cells to inflammatory signals

• Éva Rajnavölgyi,
• Renáta Laczik,
• Viktor Kun,
• Lajos Szente and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2014, 10, 3152–3160, doi:10.3762/bjoc.10.332

• study we monitored the effects of α-linoleic acid, eicosapentaenoic acid and docosahexaenoic acid solubilized in a dimethyl sulfoxide (DMSO)/ethanol 1:1 mixture or as complexed by randomly methylated α-cyclodextrin (RAMEA) on the inflammatory response of human monocyte-derived dendritic cells (moDC

• and decreased level of inflammation. Furthermore, the secretion of the T-cell polarizing cytokines IL-10 and IL-12 was also modulated in a concentration-dependent manner [10][11][12][13][14]. In these studies PUFAs were solubilized in organic solvents, such as dimethyl sulfoxide (DMSO) with or without

Synthesis of uniform cyclodextrin thioethers to transport hydrophobic drugs

• Lisa F. Becker,
• Dennis H. Schwarz and
• Gerhard Wenz

Beilstein J. Org. Chem. 2014, 10, 2920–2927, doi:10.3762/bjoc.10.310

• enter a bilayer membrane to support the API to overcome cellular barriers, such as the intestinal barrier [39] or the blood-brain barrier (BBB) [40]. Long alkyl chains (C4–C12) have already been attached via thioether or sulfoxide linkages to all primary positions by Kawabata and Ling et al. to form

(2R,1'S,2'R)- and (2S,1'S,2'R)-3-[2-Mono(di,tri)fluoromethylcyclopropyl]alanines and their incorporation into hormaomycin analogues

• Armin de Meijere,
• Sergei I. Kozhushkov,
• Dmitrii S. Yufit,
• Christian Grosse,
• Marcel Kaiser and
• Vitaly A. Raev

Beilstein J. Org. Chem. 2014, 10, 2844–2857, doi:10.3762/bjoc.10.302

• , the conversion of 20 was quantitative, and the yield of 21 was excellent (98%). In the final step, the attempted 1,3-dehydrotosylation of 22 with potassium tert-butoxide, when carried out in dimethyl sulfoxide as reported [26][27], compound 23 as an intermolecular condensation product of the expected

Synthesis of a resin monomer-soluble polyrotaxane crosslinker containing cleavable end groups

• Ji-Hun Seo,
• Shino Nakagawa,
• Koichiro Hirata and
• Nobuhiko Yui

Beilstein J. Org. Chem. 2014, 10, 2623–2629, doi:10.3762/bjoc.10.274

• synthesized. A PRX containing ca. 50 CDs with disulfide end groups was synthesized as previously reported [11]. The prepared PRX was only soluble in dimethyl sulfoxide (DMSO), and it showed poor miscibility with liquid resin monomers such as HEMA or UDMA. In order to increase the miscibility with the resin

Specific DNA duplex formation at an artificial lipid bilayer: fluorescence microscopy after Sybr Green I staining

• Emma Werz and
• Helmut Rosemeyer

Beilstein J. Org. Chem. 2014, 10, 2307–2321, doi:10.3762/bjoc.10.240

• Cy5 dye at 635 nm (Figure 2). Then, a Sybr Green I (3) solution in dimethyl sulfoxide (≈1 µg/mL) was added to the cis compartment of the slide. In the first experiment (A) laser irradiation of the intercalated dye was performed at 470 nm. In orienting experiments Sybr Green I was irradiated at 470 nm

• -phosphoethanolamine (POPE) and 1-palmitoyl-2-oleyl-sn-glycero-3-phosphocholine (POPC) were purchased from Avanti Polar Lipids (Alabaster, Al), n-decane from Alfa Aesar (Karlsruhe, Germany), dimethyl sulfoxide (DMSO), potassium chloride (KCl), 3-morpholinopropane-1-sulfonic acid (MOPS) and 2-amino-2

The effect of permodified cyclodextrins encapsulation on the photophysical properties of a polyfluorene with randomly distributed electron-donor and rotaxane electron-acceptor units

• Aurica Farcas,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert,
• Flavian Farcas,
• Iuliana Stoica and
• Anton Airinei

Beilstein J. Org. Chem. 2014, 10, 2145–2156, doi:10.3762/bjoc.10.222

• )4], β-CD and γ-CD, bromobenzene (Br–Ph), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO) were purchased from (Sigma-Aldrich) and used as received. Malononitrile (Merck), tetrabutylammonium perchlorate (TBAP) for electrochemical analysis (99.0%) (Fluka) were used without further purification