Synthesis and surface grafting of a β-cyclodextrin dimer facilitating cooperative inclusion of 2,6-ANS

• Lars W. Städe,
• Thorbjørn T. Nielsen,
• Laurent Duroux,
• Reinhard Wimmer,
• Kyoko Shimizu and
• Kim L. Larsen

Beilstein J. Org. Chem. 2015, 11, 514–523, doi:10.3762/bjoc.11.58

• interactions with the silane linker. The change in chemical composition after silanization with GPTMS and grafting of the β-CD dimer by CuAAC was verified by X-ray photoelectron spectroscopy (XPS). Table 1 displays the chemical surface composition of an unmodified, an epoxy-activated, and a β-CD-dimer-grafted

• unmodified, epoxy-activated and β-CD-dimer-grafted quartz.a Supporting Information Supporting Information File 138: 1H NMR and 13C HSQC spectra of β-CD dimer, 13C HSQC spectra of β-CD dimer in complex with 2,6-ANS and TIRF 2,6-ANS titration on bare quartz. Acknowledgements FeF Chemicals, Køge, Denmark and

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

• the previously discussed strained epoxy-derivatives could be detected. Transformation of 1,4-dienols via electro-generated iodonium cations In a similar approach we investigated the cyclisation of the 1,4-dienols 2 with in situ electrochemically generated iodonium ions for the desired synthesis of

Thermal and oxidative stability of the Ocimum basilicum L. essential oil/β-cyclodextrin supramolecular system

• Daniel I. Hădărugă,
• Nicoleta G. Hădărugă,
• Corina I. Costescu,
• Ioan David and
• Alexandra T. Gruia

Beilstein J. Org. Chem. 2014, 10, 2809–2820, doi:10.3762/bjoc.10.298

• highest degradation temperature) and for an unidentified sesquiterpene oxide (with an increase of 244%, from 0.1% to 0.3%, Table 2). Other epoxy derivatives appear upon degradation, such as ionone oxide (20). This compound was found increasingly concentrated in degraded samples (and not identified in the

Regio- and stereoselective synthesis of new diaminocyclopentanols

• Evgeni A. Larin,
• Valeri S. Kochubei and
• Yuri M. Atroshchenko

Beilstein J. Org. Chem. 2014, 10, 2513–2520, doi:10.3762/bjoc.10.262

• .10.262 Abstract The optimal conditions for regio- and stereoselective epoxide ring opening of N,N-disubstituted 1,2-epoxy-3-aminocyclopentanes by different nucleophilic reagents have been developed. The substituents on the nitrogen atom in the epoxide precursor and the orientation of the oxirane ring are

• crucial for the reaction outcome. Thus, treatment of (1RS,2SR,3SR)-1,2-epoxy-3-(N,N-dibenzylamino)cyclopentane (3b) with amines gave a mixture of C1 and C2 regioadducts, while the use of (1RS,2SR,3SR)-1,2-epoxy-3-(N-benzyl-N-methylamino)cyclopentane (3a) led ultimately to C1 adducts. Base-catalyzed

• outcome, epoxides 3c and 3d were additionally synthesized, and the results are summarized in Table 3. It has been proposed earlier that the coordination of the Lewis acid to both oxygen atoms in 2,3-epoxy alcohols and acids leads to the formation of the intermediate complex, for which nucleophiles attack

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

• silicon oxide surfaces can be obtained in only one step from an epoxy-terminated trimethoxysilane. The most common approaches to fabricate epoxide SAMs is by dip-coating or vapor condensation. However, this leads to the formation of thick films of aggregated molecular layers with undefined surface

Heronapyrrole D: A case of co-inspiration of natural product biosynthesis, total synthesis and biodiscovery

• Jens Schmidt,
• Zeinab Khalil,
• Robert J. Capon and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2014, 10, 1228–1232, doi:10.3762/bjoc.10.121

• the farnesyl residue (for atom numbering see Scheme 1), followed by regio- and stereoselective nucleophilic addition of water (and methylation) would deliver heronapyrroles A and B. Similarly, regio- and stereoselective nucleophilic addition of water to a tris-epoxy farnesyl intermediate 4 could

• produce an alternative bis-epoxy intermediate 3 that can deliver a hitherto undetected mono-tetrahydrofuran heronapyrrole (e.g., heronapyrrole D, Scheme 1). To test this hypothesis we completed an asymmetric synthesis of the putative natural product heronapyrrole D, and used this material to probe

Atherton–Todd reaction: mechanism, scope and applications

• Stéphanie S. Le Corre,
• Mathieu Berchel,
• Hélène Couthon-Gourvès,
• Jean-Pierre Haelters and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2014, 10, 1166–1196, doi:10.3762/bjoc.10.117

Metal and metal-free photocatalysts: mechanistic approach and application as photoinitiators of photopolymerization

• Jacques Lalevée,
• Sofia Telitel,
• Pu Xiao,
• Marc Lepeltier,
• Frédéric Dumur,
• Fabrice Morlet-Savary,
• Didier Gigmes and
• Jean-Pierre Fouassier

Beilstein J. Org. Chem. 2014, 10, 863–876, doi:10.3762/bjoc.10.83

• , respectively, is quite easy; polymerization of sustainable monomers can also be achieved (e.g., epoxidized soybean oil). A possible dual behavior (simultaneous generation of radicals and cations that ensure the formation of, e.g., an epoxy/acrylate interpenetrated network IPN) is achieved. Examples of PICs

• (JASCO FTIR 4100) at about 1630 cm−1 as in [15]. iv) The ring opening polymerization of epoxides: The photosensitive formulations were deposited (25 µm thick) on a BaF2 pellet under air. The evolution of the epoxy group content was continuously followed by real time FTIR spectroscopy (JASCO FTIR 4100) at

Plakilactones G and H from a marine sponge. Stereochemical determination of highly flexible systems by quantitative NMR-derived interproton distances combined with quantum mechanical calculations of ¹³C chemical shifts

• Simone Di Micco,
• Angela Zampella,
• Maria Valeria D’Auria,
• Carmen Festa,
• Simona De Marino,
• Raffaele Riccio,
• Craig P. Butts and
• Giuseppe Bifulco

Beilstein J. Org. Chem. 2013, 9, 2940–2949, doi:10.3762/bjoc.9.331

• = 2.0 and 8.0 Hz) and 2.69 (ddd, J = 2.0, 5.6, 7.5 Hz), observed in the 1H NMR spectrum, were found to correlate in the HSQC spectrum with two oxygenated carbons at δC 63.3 and 61.6, respectively, and were assigned to an epoxy ring. The localization of the epoxy functionality at C-7 and the structure

N,N'-(Hexane-1,6-diyl)bis(4-methyl-N-(oxiran-2-ylmethyl)benzenesulfonamide): Synthesis via cyclodextrin mediated N-alkylation in aqueous solution and further Prilezhaev epoxidation

• Julian Fischer,
• Simon Millan and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 2834–2840, doi:10.3762/bjoc.9.318

• adequate phase transfer catalysts and the cyclodextrin–guest complexes were characterized by 1H NMR and 2D NMR ROESY spectroscopy. Finally, the curing properties of the diepoxide with lysine-based α-amino-ε-caprolactam were analyzed by rheological measurements. Keywords: alkylation; cyclodextrins; epoxy

• Hz, 2H, O–CH2, trans), 2.40 (s, 6H, Ar-CH3), 1.55 (m, 4H, -CH2-), 1.27 (m, 4H, -CH2-); 13C NMR (75 MHz, CDCl3, δ) 143.6 (2C, Ar(C)-CH3), 136.8 (2C, RO2S-(C)Ar), 130.0 (4C, Ar(C)), 127.3 (4C, Ar(C)), 51.2 (2C, epoxy), 51.0 (2C, N-CH2-CH2R), 49.4 (2C, N-CH2-epoxy), 45.4 (2C, epoxy), 28.5 (2C, -CH2

Oligomeric epoxide–amine adducts based on 2-amino-N-isopropylacetamide and α-amino-ε-caprolactam: Solubility in presence of cyclodextrin and curing properties

• Julian Fischer and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 2803–2811, doi:10.3762/bjoc.9.315

• with hydrophobic guest molecules is widely used in drug, food, cosmetics, textile, adhesives, plastics and more industries [11][12][13]. Interestingly, recently it was confirmed that α- and β-CD cannot interact with PNIPAM. Only γ-CD has a tendency to include the PNIPAM main chain [14]. Normally, epoxy

• resins exhibit poor solubility in water [15][16][17]. Accordingly, epoxide–amine polymers are not yet deeply investigated in respect to LCST behavior [18][19]. At present, most available bio-based and water soluble epoxy resins are expensive and use petroleum-based curing agents [20]. Thus, in the

• present paper we wish to describe our results about preparation and solubility of novel bio-based amine–epoxy oligoadducts. Also, we present some effects of CD on the solubility of these oligomers. Results and Discussion Generally, primary amins are bifunctional towards diepoxides and are thus monomers

Silica sulfuric acid: a reusable solid catalyst for one pot synthesis of densely substituted pyrrole-fused isocoumarins under solvent-free conditions

• Sudipta Pathak,
• Kamalesh Debnath and
• Animesh Pramanik

Beilstein J. Org. Chem. 2013, 9, 2344–2353, doi:10.3762/bjoc.9.269

• sulfonic group of SSA generates dehydrated cationic intermediate 9. This reactive intermediate 9 provokes a nucleophilic attack of primary amines to form bicyclo[3.3.0]octanamino compound 10. Then the α-hydroxy group of 10 attacks the adjacent carbonyl carbon to generate epoxy intermediate 11. This

• unstable epoxy intermediate 11 produces a six-membered lactone intermediate 12 through the breaking of a C–C bond. Subsequently, intermediate 12 tautomerizes to 13 under formation of the isocoumarin skeleton. The dihydropyrrole-fused isocoumarin intermediate 14 is formed through the intramolecular

• nucleophilic attack of the secondary amine group to the carbonyl carbon of 13. Finally, intermediate 14 loses water to furnish pyrrole-fused isocoumarins 5 or 8. It is worth mentioning that in the previous method instead of the formation of epoxy intermediate like 11 a transannular rearrangement was proposed

Flow synthesis of phenylserine using threonine aldolase immobilized on Eupergit support

• Jagdish D. Tibhe,
• Hui Fu,
• Timothy Noël,
• Qi Wang,
• Jan Meuldijk and
• Volker Hessel

Beilstein J. Org. Chem. 2013, 9, 2168–2179, doi:10.3762/bjoc.9.254

• acrylic beads provide a rapid and simple support for immobilization and have been used to immobilize various enzymes for a number of reactions [46]. Immobilization on Eupergit (a porous material) can be achieved without the need for any additional reagents, as the epoxy groups on Eupergit can react

• directly with the nucleophilic groups of the enzyme by forming strong covalent linkages like amino, hydroxy or mercapto functional groups. Eupergit has a high density of epoxy groups on the surface (oxirane density 300 μmol/g dry beads [47]), increasing the possibility of multipoint attachment of the

• each other which resulted in higher values for enzyme retention. For the indirect method, however, the epoxy groups were converted into aldehyde groups. These groups can only react with nucleophiles such as amino groups. During treatment of Eupergit with ethylenediamine, a coupling of two adjacent

A concise enantioselective synthesis of the guaiane sesquiterpene (−)-oxyphyllol

• Martin Zahel and
• Peter Metz

Beilstein J. Org. Chem. 2013, 9, 2028–2032, doi:10.3762/bjoc.9.239

• Martin Zahel Peter Metz Fachrichtung Chemie und Lebensmittelchemie, Organische Chemie I, Technische Universität Dresden, Bergstrasse 66, 01069 Dresden, Germany 10.3762/bjoc.9.239 Abstract (−)-Oxyphyllol was prepared in only 4 steps from an epoxy enone that already served as an intermediate for

• 3 can be utilized to generate the isopropyl group, and a regioselective transannular epoxide opening would construct the oxygen-bridged bicyclic hydroazulene framework. Alcohol 3 was traced back to the known epoxy enone 4 that already served as an intermediate for the total synthesis of 5 [6]. As

Exploration of an epoxidation–ring-opening strategy for the synthesis of lyconadin A and discovery of an unexpected Payne rearrangement

• Brad M. Loertscher,
• Yu Zhang and
• Steven L. Castle

Beilstein J. Org. Chem. 2013, 9, 1179–1184, doi:10.3762/bjoc.9.132

• complex [29] at the less-hindered carbon of the epoxide would provide 26. Acid- and Lewis acid promoted Payne rearrangements of epoxy alcohols [33][34] and epoxy methyl ethers [35] have been described, but we are unaware of any prior reports of Payne rearrangements of the bulkier epoxy trityl ethers

Efficient regio- and stereoselective access to novel fluorinated β-aminocyclohexanecarboxylates

• Loránd Kiss,
• Melinda Nonn,
• Reijo Sillanpää,
• Santos Fustero and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2013, 9, 1164–1169, doi:10.3762/bjoc.9.130

• bond oxidation with 3-chloroperbenzoic acid (MCPBA) to afford epoxy amino ester 6 cis-diastereoselectively [57] (Scheme 1). Opening of the oxirane ring in 6 with NaBH4 in EtOH at 70 °C proceeded regioselectively, providing exclusively amino ester 5 with the hydroxy function on position 4 (for analogous

Facile synthesis of functionalized spiro[indoline-3,2'-oxiran]-2-ones by Darzens reaction

• Qin Fu and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 918–924, doi:10.3762/bjoc.9.105

• . The 1H NMR spectra of compounds 3a–h and 4a–e usually show one set of characteristic peaks for each group, especially one singlet at about 5.10 ppm for one proton of the epoxy unit, which clearly indicates that only one isomer exists in each sample. However, 1H NMR spectra of compounds 3a and 3f

• ratios. It is known that the closure of the epoxy ring would form cis/trans isomers in the Darzens reaction process. Here the N-benzyl and the N-butyl group in the oxindole moiety may decrease the steric effect of formation of the epoxy ring and lead to the easier formation of the relatively unstable cis

New core-pyrene π structure organophotocatalysts usable as highly efficient photoinitiators

• Sofia Telitel,
• Frédéric Dumur,
• Thomas Faury,
• Bernadette Graff,
• Mohamad-Ali Tehfe,
• Didier Gigmes,
• Jean-Pierre Fouassier and
• Jacques Lalevée

Beilstein J. Org. Chem. 2013, 9, 877–890, doi:10.3762/bjoc.9.101

• of the epoxy content was also continuously followed by real-time FTIR spectroscopy (FTIR NEXUS 870). A Xe–Hg lamp (Hamamatsu, L8252, 150 W, filtered light at λ > 340 nm; intensity ~ 30 mW/cm²) and a halogen lamp (intensity ~10 mW/cm²; the emission spectrum is given in [43]) were used as the

Asymmetric total synthesis of smyrindiol employing an organocatalytic aldol key step

• Dieter Enders,
• Jeanne Fronert,
• Tom Bisschops and
• Florian Boeck

Beilstein J. Org. Chem. 2012, 8, 1112–1117, doi:10.3762/bjoc.8.123

• ). A few years later Snider et al. described the, up to now, sole total synthesis of smyrindiol using an enantiomerically pure epoxy aldehyde [9]. The two possible diastereoisomers resulting from the addition of the epoxy aldehyde to the coumaryl Grignard intermediate, occurred with low

Synthesis of a library of tricyclic azepinoisoindolinones

• Bettina Miller,
• Shuli Mao,
• Kara M. George Rosenker,
• Joshua G. Pierce and
• Peter Wipf

Beilstein J. Org. Chem. 2012, 8, 1091–1097, doi:10.3762/bjoc.8.120

• . When the RCM reaction of 7 was conducted on larger scale in the absence of Ti(OiPr)4, and the crude intermediate was subjected to m-CPBA oxidation, epoxy alcohol 6 was isolated in 11% overall yield. LC–MS as well as NMR analyses suggested a 5:1 ratio of epimers at the hemiacetal carbon. Hydroxylation

Unprecedented deoxygenation at C-7 of the ansamitocin core during mutasynthetic biotransformations

• Tobias Knobloch,
• Gerald Dräger,
• Wera Collisi,
• Florenz Sasse and
• Andreas Kirschning

Beilstein J. Org. Chem. 2012, 8, 861–869, doi:10.3762/bjoc.8.96

• produces the expected ansamitocin derivative 14 in good yield (Scheme 4) [28]. Besides the ester side chain, compound 14 also lacks the epoxy functionality and the N-methyl group. These two tailoring steps finalize the biosynthesis of ansamitocin P-3 (AP-3, 4) and occur only after acylation has taken place

An easy α-glycosylation methodology for the synthesis and stereochemistry of mycoplasma α-glycolipid antigens

• Yoshihiro Nishida,
• Yuko Shingu,
• Yuan Mengfei,
• Kazuo Fukuda,
• Hirofumi Dohi,
• Sachie Matsuda and
• Kazuhiro Matsuda

Beilstein J. Org. Chem. 2012, 8, 629–639, doi:10.3762/bjoc.8.70

• -glycosyl bromide species [32]. In the pathway using DMF, the α-glycosylation is routed via α-glycosyl cationic imidate 3, which was predicted in former studies [33] and evidenced in our preceding NMR and MS study [25][26]. The reaction between 1 and (S)-glycidol in CH2Cl2 (+ TMU) gave a mixture of epoxy

Intramolecular carbenoid ylide forming reactions of 2-diazo-3-keto-4-phthalimidocarboxylic esters derived from methionine and cysteine

• Marc Enßle,
• Stefan Buck,
• Roland Werz and
• Gerhard Maas

Beilstein J. Org. Chem. 2012, 8, 433–440, doi:10.3762/bjoc.8.49

• . Characteristics are the signals for the NCH proton (13a: δ = 4.60 ppm; 13b: δ = 4.67 ppm) and the two bridgehead carbons of the epoxy bridge (13a: δ = 86.60 and 94.13 ppm; 13b: δ = 86.75 and 94.04 ppm). While a CI mass spectrum of 13b showed a weak molecular-ion peak for the dimer (the base peak representing the

• monomer unit), in the case of 13a, even under these mild conditions of chemical ionisation, the spectrum showed no peak at m/z greater than that for the monomer, which was again the base peak. The relative stereochemistry shown in Scheme 4, with the two epoxy bridges in syn relationship and the

Improved syntheses of high hole mobility phthalocyanines: A case of steric assistance in the cyclo-oligomerisation of phthalonitriles

• Daniel J. Tate,
• Rémi Anémian,
• Richard J. Bushby,
• Suwat Nanan,
• Stuart L. Warriner and
• and Benjamin J. Whitaker

Beilstein J. Org. Chem. 2012, 8, 120–128, doi:10.3762/bjoc.8.14

• calibrated with indium (mp 156.60, ΔH = 28.53 J·g−1) and a heating/cooling rate of 10 °C·min−1. Time-of-flight photoconductivity studies The cells were assembled in a laminar-flow hood to avoid contamination by dust or grease. Each ITO-coated glass slide was connected to a copper wire by epoxy resin (Aradite

• ) and the tip of the wire was bonded to the ITO surface with silver paint (RS 186-3600). The two halves were separated by a PET spacer (Goodfellow Cambridge Limited) with a thickness of 23 μm, held in position with clips and secured with epoxy resin. The thickness of the cell (d) was accurately

Imidazole as a parent π-conjugated backbone in charge-transfer chromophores

• Jiří Kulhánek and
• Filip Bureš

Beilstein J. Org. Chem. 2012, 8, 25–49, doi:10.3762/bjoc.8.4

• and co-workers reported the synthesis of epoxy-based nonlinear optical polymers 144 functionalized by post-azo coupling (Figure 23; [130]). The parent polymer backbone was synthesized from diglycidyl ether of bisphenol A and aniline and was further functionalized by diazotized amine 83 (Figure 15

• -functionalized chromophores incorporated into a polymer backbone Rpol [18][50][51][52][53][122][123][124]. Structure of polyphosphazene polymers bearing NLO-phores [125][126][127] and some other recent examples of nonlinear optical polymers [19][128]. Epoxy- and silica-based polymers functionalized with 4,5