Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

• Pierre Boufflet,
• Sebastian Wood,
• Jessica Wade,
• Zhuping Fei,
• Ji-Seon Kim and
• Martin Heeney

Beilstein J. Org. Chem. 2016, 12, 2150–2163, doi:10.3762/bjoc.12.205

• likely indicates less inter- and intrachain coupling, and possibly a frustration of the crystallization and phase separation in the case of these block copolymers. Thermal behavior Differential scanning calorimetry Fluorination of P3OT has previously been shown to result in a 50–60 °C increase in the

• melting and crystallization temperatures, an effect that was predominantly attributed to the increased backbone planarity and rigidity in combination with the increased aggregation it engenders [42]. In order to probe the crystallization behavior of the block copolymers and blends in thin films, DSC was

• [42]), which could result in a masking of the P3OT melt in the baseline. However, the apparent suppression of the P3OT melt could also be explained by some degree of frustration of the P3OT crystallization, likely due to the earlier precipitation of the less soluble F-P3OT during the film formation

Synthesis and properties of fluorescent 4′-azulenyl-functionalized 2,2′:6′,2″-terpyridines

• Adrian E. Ion,
• Liliana Cristian,
• Mariana Voicescu,
• Masroor Bangesh,
• Augustin M. Madalan,
• Daniela Bala,
• Constantin Mihailciuc and
• Simona Nica

Beilstein J. Org. Chem. 2016, 12, 1812–1825, doi:10.3762/bjoc.12.171

• 4b. These substituents are also responsible for the upfield shift of the azulene proton resonances, the most affected being the azulene protons at the 2- and 3-positions (Table 2). Crystals suitable for X-ray diffraction could be isolated for both compounds by crystallization from methanol

Synthesis of ferrocenyl-substituted 1,3-dithiolanes via [3 + 2]-cycloadditions of ferrocenyl hetaryl thioketones with thiocarbonyl S-methanides

• Grzegorz Mlostoń,
• Róża Hamera-Fałdyga,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2016, 12, 1421–1427, doi:10.3762/bjoc.12.136

• crude products were purified by crystallization (hexane/CH2Cl2). Preparation of cycloaliphatic-substituted 1,3-dithiolanes (5h–l, 6h–m) – General procedure: To a solution of the corresponding ferrocenyl-substituted thioketone 1 (1 mmol) in THF (4 mL), 1,3,4-thiadiazoline 3c or 3d (1 mmol) was added. The

Biradical vs singlet oxygen photogeneration in suprofen–cholesterol systems

• Fabrizio Palumbo,
• Francisco Bosca,
• Isabel M. Morera,
• Inmaculada Andreu and
• Miguel A. Miranda

Beilstein J. Org. Chem. 2016, 12, 1196–1202, doi:10.3762/bjoc.12.115

• ]. They were purified and resolved into the pure diastereoisomers by fractional crystallization from hexane/ethyl acetate. Ester 1 was obtained as a pure solid, while its diastereoisomer 2 remained as a viscous oil after elimination of the solvent from the filtered solution. In order to make an

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

• these chiral sulfoxides needed to be explored, preferably one that did not rely on crystallization. In 2005, the Senanayake group described a process in which (+)-norephedrine-derived oxathiazolidine 2-oxides are used as sulfinyl transfer agents in the synthesis of optically pure sulfoxides and

Synthesis and in vitro cytotoxicity of acetylated 3-fluoro, 4-fluoro and 3,4-difluoro analogs of D-glucosamine and D-galactosamine

• Štěpán Horník,
• Lucie Červenková Šťastná,
• Petra Cuřínová,
• Jan Sýkora,
• Kateřina Káňová,
• Roman Hrstka,
• Ivana Císařová,
• Martin Dračínský and
• Jindřich Karban

Beilstein J. Org. Chem. 2016, 12, 750–759, doi:10.3762/bjoc.12.75

• in ca. 8% was observed in NMR spectra. The desired D-galacto-configured 2-azido derivative 31 was separated from 32 by crystallization in 74% yield. The D-galacto configuration of 31 is evidenced by the vicinal coupling values 3JH4,H3/5 = 4.5 Hz and the long range coupling between equatorial protons

Creating molecular macrocycles for anion recognition

• Amar H. Flood

Beilstein J. Org. Chem. 2016, 12, 611–627, doi:10.3762/bjoc.12.60

• their propensity to stack. This can be seen in the crystalline phase with dimer formation either around anionic guests like perchlorate [36] (Figure 14a) or, in the absence of an anion, around adventitious solvents of crystallization, like diglyme (Figure 14b) [37] . The π-surface was enhanced by

Biosynthesis of α-pyrones

• Till F. Schäberle

Beilstein J. Org. Chem. 2016, 12, 571–588, doi:10.3762/bjoc.12.56

• cysteine as a result of substrate incubation prior to crystallization. This was only possible with a very short substrate mimic which renders more similarity to the eastern chain. Using the longer western chain mimic no suitable crystals for structure determination could be produced (neither for CorB, nor

My maize and blue brick road to physical organic chemistry in materials

• Anne J. McNeil

Beilstein J. Org. Chem. 2016, 12, 229–238, doi:10.3762/bjoc.12.24

• different example, we hypothesized that polymeric additives, commonly utilized to alter crystallization processes, might be useful for lowering the cgc in gel formation. Graduate student Yash Adhia, working with undergraduates Tracy Schloemer and Maria Perez, screened a series of commercially available

Thermal and oxidative stability of Atlantic salmon oil (Salmo salar L.) and complexation with β-cyclodextrin

• Daniel I. Hădărugă,
• Mustafa Ünlüsayin,
• Alexandra T. Gruia,
• Cristina Birău (Mitroi),
• Gerlinde Rusu and
• Nicoleta G. Hădărugă

Beilstein J. Org. Chem. 2016, 12, 179–191, doi:10.3762/bjoc.12.20

• saturated fatty acids remained constant or slightly increased by a few percent after degradation (e.g., from 10.7% to 12.9% for palmitic acid). Co-crystallization of ASO with β-CD at a host–guest ratio of 1:1 and 3:1 from an ethanol–water mixture and kneading methods has been used for the preparation of β

• and microencapsulation of fish oil is also used [43][44]. However, no CD complexation studies on ASO have been published up to now. The goal of this study was to evaluate the thermal and oxidative stability of ASO (Salmo salar L.) and the β-CD complexation by using co-crystallization and kneading

• degradation of ASO at low and high temperature degradation conditions. Preparation and analysis of β-CD/ASO complexes β-CD/ASO complexes were obtained by using two different methods: co-crystallization from an ethanol–water mixture and by kneading techniques. No literature data on β-CD/ASO complexes have been

Diastereoselective Ugi reaction of chiral 1,3-aminoalcohols derived from an organocatalytic Mannich reaction

• Samantha Caputo,
• Andrea Basso,
• Lisa Moni,
• Renata Riva,
• Valeria Rocca and
• Luca Banfi

Beilstein J. Org. Chem. 2016, 12, 139–143, doi:10.3762/bjoc.12.15

• , by additional crystallization, affording these key intermediates in high ee and de (syn relative configuration, see Supporting Information File 1). The tert-butyl urethane was then deblocked with trifluoroacetic acid. Neutralization and extraction afforded crude aminoalcohols 5a–e, that were directly

Synthesis and reactivity of aliphatic sulfur pentafluorides from substituted (pentafluorosulfanyl)benzenes

• Norbert Vida,
• Jiří Václavík and
• Petr Beier

Beilstein J. Org. Chem. 2016, 12, 110–116, doi:10.3762/bjoc.12.12

• . Maleic acid 4 was identified in the mixture (25% 19F NMR yield, Scheme 4) but chromatographic separation, crystallization or derivatization (CH2N2) attempts were not successful. Nevertheless, these results show that SF5-substituted para-benzoquinones are most likely intermediates in the formation of 4 by

Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation

• Jie Wang,
• Zhiqiang Qiu,
• Yiming Wang,
• Li Li,
• Xuhong Guo,
• Duc-Truc Pham,
• Stephen F. Lincoln and
• Robert K. Prud’homme

Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7

• form hydrogels [84][85]. In particular, hydrogels formed by PEG and cyclodextrins have been investigated intensively because of the biocompatibility of their components. Interestingly, local crystallization of the polyrotaxane threaded cyclodextrins, sometimes called molecular necklaces [86], may form

• studies were also consistent with the localized crystallization of α-CD/PEG pseudo-polyrotaxanes forming interchain cross-links in the hydrogel. Low molecular weight <2 kDa PEG forms crystalline precipitates in aqueous solutions in the presence of α-CD largely because multiple α-CD thread onto the PEG

New metathesis catalyst bearing chromanyl moieties at the N-heterocyclic carbene ligand

• Agnieszka Hryniewicka,
• Szymon Suchodolski,
• Agnieszka Wojtkielewicz,
• Jacek W. Morzycki and
• Stanisław Witkowski

Beilstein J. Org. Chem. 2015, 11, 2795–2804, doi:10.3762/bjoc.11.300

• were washed with brine and water, dried over Na2SO4 and evaporated to dryness. After crystallization from ethanol a white solid was obtained (480 mg, 90%). Mp 182–183 °C; IR (KBr) ν: 3369, 2968, 2925, 2779, 1450, 1420, 1265 cm−1; 1H NMR (400 MHz, CDCl3) δ 3.04 (s, 4H, -NCH2CH2N-), 2.64 (t, J = 6.8 Hz

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

• analysis (TGA). All copolymers showed only glass-transitions (Tg) and not any exothermal crystallization peak characteristic of polymers containing 9,9-dioctyl-2,7-fluorene units (PFO) [49], Figure 2. The non-rotaxane copolymer 3 has a Tg at 88 °C. The Tg value increases for 3·TM-γCD and 3·TM-βCD to 96 °C

Bifunctional phase-transfer catalysis in the asymmetric synthesis of biologically active isoindolinones

• Antonia Di Mola,
• Maximilian Tiffner,
• Francesco Scorzelli,
• Laura Palombi,
• Rosanna Filosa,
• Paolo De Caprariis,
• Mario Waser and
• Antonio Massa

Beilstein J. Org. Chem. 2015, 11, 2591–2599, doi:10.3762/bjoc.11.279

• reaction time (72 h) [21][22]. Readily available chiral ammonium salts (e.g., cinchona alkaloid-based or commercially available Maruoka catalysts) were also investigated, but the enantioselectivity was lower, reaching a maximum of 46% ee [23]. Gratifyingly, a very efficient heterochiral crystallization

• successfully scaled up to a practical 2 mmol scale with unchanged efficiency. After crystallization, we were able to obtain reasonable quantities of (S)-7 with 95% ee and an overall yield of 77%. The availability of both the enantiomers of the catalysts is another important advantage because of the possibility

• after crystallization overnight at −20 °C, the solid was filtered off and the solution containing the enantioenriched compound was evaporated and analyzed by chiral HPLC. The resulting enantioenriched product was obtained as a colourless oil in 77% overall yield (400 mg, 1.51 mmol, 95% ee). The

Stereoselective synthesis of hernandulcin, peroxylippidulcine A, lippidulcines A, B and C and taste evaluation

• Marco G. Rigamonti and
• Francesco G. Gatti

Beilstein J. Org. Chem. 2015, 11, 2117–2124, doi:10.3762/bjoc.11.228

• ]. Indeed, the treatment of (–)-isopulegol with diisopropyl azodicarboxylate (DIAD) and p-nitrobenzoic acid in the presence of triphenylphosphine gave the corresponding ester in an almost quantitative yield. The latter was easily purified by crystallization from n-hexane, and then transesterificated with

• epoxidation of 5 with tert-butylhydroperoxide (TBHP) in toluene gave 6 ([α]D +34.2° (c 1.3, CHCl3)) in 95% yield [9][22]. Then, the diol 7 was obtained in 85% yield from the reduction of epoxide 6 with LiAlH4 in THF at 0 °C. The diol 7 was easily purified by crystallization (85% yield, n-hexane at −50 °C up

Effective ascorbate-free and photolatent click reactions in water using a photoreducible copper(II)-ethylenediamine precatalyst

• Redouane Beniazza,
• Natalia Bayo,
• Florian Molton,
• Carole Duboc,
• Stéphane Massip,
• Nathan McClenaghan,
• Dominique Lastécouères and
• Jean-Marc Vincent

Beilstein J. Org. Chem. 2015, 11, 1950–1959, doi:10.3762/bjoc.11.211

• vapour into the THF solution led to the crystallization of 1 as blue needles, which were recovered by filtration (71% yield). The proposed dinuclear and mononuclear structures of 4 and 1 were confirmed by single crystal X-ray diffraction (Figure 1). The crystal structure of 4 displays the typical “paddle

Cross-metathesis of polynorbornene with polyoctenamer: a kinetic study

• Yulia I. Denisova,
• Maria L. Gringolts,
• Alexander S. Peregudov,
• Liya B. Krentsel,
• Ekaterina A. Litmanovich,
• Arkadiy D. Litmanovich,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2015, 11, 1796–1808, doi:10.3762/bjoc.11.195

• measurements with PCOE are impossible since the solution is not filterable through a 220 nm porosity membrane. Taking into account that the melting temperature of PCOE is about 45 °C, we can relate aggregation in the PCOE solutions at 25 °C to the onset of crystallization. In any case, it makes no sense to

Synthesis and structures of ruthenium–NHC complexes and their catalysis in hydrogen transfer reaction

• Chao Chen,
• Chunxin Lu,
• Qing Zheng,
• Shengliang Ni,
• Min Zhang and
• Wanzhi Chen

Beilstein J. Org. Chem. 2015, 11, 1786–1795, doi:10.3762/bjoc.11.194

• -phenanthroline in heat acetonitrile solution afforded 4 and 5, respectively. Even excess triphenylphosphine and 1,10-phenanthroline were used, only one and two coordinated acetonitrile ligands were substituted in complexes 4 and 5. Crystallization by slow diffusion of diethyl ether into their acetonitrile

• crystallization by slow diffusion of Et2O into the CH3CN solution gave 4 as yellow solid. Yield: 75 mg, 40%. Anal. calcd for C32H32F12N7P3Ru: C, 41.04; H, 3.44; N, 10.47; found: C, 41.10; H, 3.40; N, 10.58; 1H NMR (DMSO-d6) δ 8.99 (s, 1H), 8.46 (s, 1H), 8.38 (s, 1H), 7.87 (s, 1H), 7.57(s, 13H), 7.42 (s, 2H), 7.25

• ). A mixture of 2 (142 mg, 0.2 mmol) and 1,10-phenanthroline·1H2O (198 mg, 1.0 mmol) in 5 mL CH3CN was stirred at 80 °C for 6 h. Then the mixture was filtered through Celite to afford a yellow solution. Crystallization by slow diffusion of Et2O into the CH3CN solution gave 5 as an orange yellow solid

Towards inhibitors of glycosyltransferases: A novel approach to the synthesis of 3-acetamido-3-deoxy-D-psicofuranose derivatives

• Maroš Bella,
• Miroslav Koóš and
• Chun-Hung Lin

Beilstein J. Org. Chem. 2015, 11, 1547–1552, doi:10.3762/bjoc.11.170

• single-crystal X-ray analysis. However, removal of the pivaloyl group from derivative 10 afforded 3-acetamido-3-deoxy-1,2-O-isopropylidene-α-D-psicofuranose (12) which, after crystallization (EtOAc/hexane 1:2), afforded crystals suitable for X-ray analysis. This unambiguously confirmed the α

• -psicofuranoside derivative 15. X-ray analysis Single crystals (stable at ambient temperature) that were suitable for X-ray diffraction measurements were obtained by slow crystallization of 12 from EtOAc/hexane 1:2 with cooling in a refrigerator. The preliminary orientation matrices and final cell parameters were

The enantioselective synthesis of (S)-(+)-mianserin and (S)-(+)-epinastine

• Piotr Roszkowski,
• Jan. K. Maurin and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2015, 11, 1509–1513, doi:10.3762/bjoc.11.164

• recrystallization was applied. The values of specific rotation were [α]D23 +68.1 (c 1, CHCl3) and [α]D23 −68.3 (c 1, CHCl3), which could not be changed by repeated crystallization steps. Confirmation of the optical purity of compound 7 by HPLC (Daicel OD-H) could not be obtained because of its insufficient

Synthesis of a tricyclic lactam via Beckmann rearrangement and ring-rearrangement metathesis as key steps

• Sambasivarao Kotha,
• Ongolu Ravikumar and
• Jadab Majhi

Beilstein J. Org. Chem. 2015, 11, 1503–1508, doi:10.3762/bjoc.11.163

• = 2:1) (Scheme 2) but the products were inseparable by column chromatography. Next, we attempted to separate the mixture of these isomers (9a and 9b) by selective crystallization using different solvent systems. Finally, one of the lactam derivative 9a (δ = 3.86, dd, J = 5.8, 2.9 Hz, 1H) was isolated

• same Rf value of the individual compounds. Finally, isolation of the required lactam 9a from the mixture was accomplished by using crystallization. Since this method is cumbersome, an alternate method was attempted. To this end, we changed our synthetic route and tried to use the unsaturated ketone 4

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

• candidates for the formation of metal complexes. We have therefore investigated the complexation of L1 and L2 with various metal cations and we succeeded in the crystallization of a neutral rhenium metal complex with ligand L2. Thus, the equimolar reaction between L2 and the [Re(CO)5Cl] precursor performed

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

• nitrogen atoms to form a planar palladium ring system (Scheme 2). Crystallization by slow diffusion of pentane into a solution of 8 in dichloromethane gave suitable crystals for an X-ray diffraction study. The molecular structure is presented in Figure 2 (see Supporting Information File 1 for the cif of