Electrochemical oxidation of cholesterol

• Jacek W. Morzycki and
• Andrzej Sobkowiak

Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45

• numeral, but the acetylated derivative is amended by the letter “a”, e.g., cholesterol (1) and cholesteryl acetate (1a). Indirect electrochemical oxidation of cholesterol The selective oxidation of saturated hydrocarbons by dioxygen and hydrogen peroxide remains a challenging problem in chemistry and

• . Many investigations on oxygenation reactions have been carried out by using a simple, readily available reagent system mimicking monooxygenase enzymes. An interesting system for the oxidation of aliphatic hydrocarbons, consisting of oxygen, powdered zinc, pyridine, acetic acid, and a catalytic amount

Attempts to prepare an all-carbon indigoid system

• Şeref Yildizhan,
• Henning Hopf and
• Peter G. Jones

Beilstein J. Org. Chem. 2015, 11, 363–372, doi:10.3762/bjoc.11.42

• ], the recent preparative accomplishments of the Sherburn group have changed the situation fundamentally [5][6]. These cross-conjugated hydrocarbons are now known up to [13]dendralene, and many of these potentially very valuable compounds are available in gram quantities, allowing, often for the first

• always in the form of mixtures also containing other isomers. As far as we are aware, the above route is the only one that provides isomerically pure 23, not surprising in view of its route of formation. These isomeric hydrocarbons are useful ligands for the preparation of bridged Ziegler–Natta catalysts

• tert-BuLi in THF and the presumably resulting bis-anion quenched with 1,2-dibromoethane, a complex product mixture consisting largely of polymeric material was formed. From this mixture, however, trace amounts of two hydrocarbons (total yield 5%) could be separated by thin layer chromatography. Further

Articulated rods – a novel class of molecular rods based on oligospiroketals (OSK)

• Pablo Wessig,
• Roswitha Merkel and
• Peter Müller

Beilstein J. Org. Chem. 2015, 11, 74–84, doi:10.3762/bjoc.11.11

• these types should therefore facilitate very interesting applications for ARs. As mentioned above, compound 32a can serve as a probe for this equilibrium owing to the pyrene moieties. As many polyaromatic hydrocarbons pyrene possess a marked tendency to form excimers in the excited state [23]. The broad

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

• affinity towards rocuronium [24][25]. Furthermore, hydrophilic γ-CD thioethers show high affinities to other guests such as polycyclic aromatic hydrocarbons [26], botulin [27][28], and fullerene C60 [29]. Hydrophilic β-CD thioethers also tightly complex volatile benzene derivatives leading to a significant

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

• properties, and its antimicrobial [19] biological effects. Moreover, the anticancer potential of basil components has been studied [24]. These sensory and pharmaceutical properties of basil are primarily due to the presence of essential oil components, which consist of monoterpene hydrocarbons (e.g., β

• -pinene), oxygenated monoterpenes (eucalyptol, linalool, α-terpineol, borneol and its acetate), phenolic derivatives (eugenol, methylchavicol (estragole)), sesquiterpene hydrocarbons (β-cubebene, β-caryophyllene, germacrene, etc.), and oxygenated sesquiterpenes (cadinol, spathulenol) [9][16][20][25

• for sesquiterpenes (hydrocarbons), in comparison with the corresponding oxygenated sesquiterpenes exists. The above mentioned α-cadinol (18) and spathulenol (16) were identified in the encapsulated essential oil at reduced concentrations of 34.5% and 84.5%, respectively. This reduction in

Self-assembled monolayers of shape-persistent macrocycles on graphite: interior design and conformational polymorphism

• Joscha Vollmeyer,
• Friederike Eberhagen,
• Sigurd Höger and
• Stefan-S. Jester

Beilstein J. Org. Chem. 2014, 10, 2774–2782, doi:10.3762/bjoc.10.294

• –HOPG and macrocycle–macrocycle interactions, the following key aspects must be considered: (i) how the extraannular alkyl side chains of the adsorbed macrocycles pack, and whether this can be compared to the packing of linear hydrocarbons on HOPG, (ii) how the specific attachment of the extraannular

Removal of volatile organic compounds using amphiphilic cyclodextrin-coated polypropylene

• Ludmilla Lumholdt,
• Sophie Fourmentin,
• Thorbjørn T. Nielsen and
• Kim L. Larsen

Beilstein J. Org. Chem. 2014, 10, 2743–2750, doi:10.3762/bjoc.10.290

• in order to improve the aquatic ecosystem [1]. Later in 2008, the EU elaborated on the Water Framework Directive defining several problematic compounds, including various pesticides, endocrine disruptors, and hydrocarbons such as benzene and benzene derivatives, as compounds requiring immediate and

• could provide a full removal of the tested compounds [3]. Biological treatment of wastewater shows a high efficiency towards the removal of hydrocarbons, however, some bacteria cannot tolerate the elevated concentrations of the chemicals, resulting in a low removal efficiency [4][5][6]. Consequently

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

• Véronique Nardello-Rataj and
• Loïc Leclercq

Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273

• complexes. Therefore, the essential oils were protected by the β-CD encapsulation. As a consequence, the essential oils remain effective as antimicrobial agents for longer time periods and under a wide variety of environmental conditions. On the other hand, the biodegradation of hydrocarbons is influenced

• by their bioavailability [52]. Indeed, hydrocarbons are very poorly soluble in water. Therefore, their metabolization by microorganisms is very difficult. To overcome this drawback, surfactants are used to improve their aqueous solubility and their bioavailability in order to accelerate the

Microsolvation and sp²-stereoinversion of monomeric α-(2,6-di-tert-butylphenyl)vinyllithium as measured by NMR

• Rudolf Knorr,
• Monika Knittl and
• Eva C. Rossmann

Beilstein J. Org. Chem. 2014, 10, 2521–2530, doi:10.3762/bjoc.10.263

• immediately from 5 with n-Bu6Li in the absence of TMEDA in a less clean (pale violet) THF/hydrocarbons mixture (47:53% by volume). These coincidences established that even considerable amounts of residual n-Bu6Li and the emerging tetrameric Me6Li did not form mixed aggregates with 4 in THF. The further

• , [15]), whereas the notoriously variable [19] 1H NMR data evaded a simple interpretation. Importantly, separate NMR signals were observed for free and coordinated TMEDA (1 equiv) at and below −44 °C. In TMEDA/hydrocarbons (64:36) as the solvent, the quick Sn/Li interchange reaction of 5 with n-Bu6Li at

• , [15]). The high concentration of (CH3Li)4 did not change during the slow decay of 4&TMEDA at rt through proton transfer from the solvent TMEDA [20][21] that formed olefin 8a, Me2N–CH=CH2, and LiNMe2. In Et2O/hydrocarbons (54:46) without TMEDA, the Sn/Li interchange reaction of 5 and n-Bu6Li was very

Electrocarboxylation: towards sustainable and efficient synthesis of valuable carboxylic acids

• Roman Matthessen,
• Jan Fransaer,
• Koen Binnemans and
• Dirk E. De Vos

Beilstein J. Org. Chem. 2014, 10, 2484–2500, doi:10.3762/bjoc.10.260

• process provides a feasible route to methoxymethane-1,1,1’-tricarboxylate salts, which are excellent detergent builders. The reaction should be carried out in strictly anhydrous conditions, since water is a stronger acid than the weakly acidic hydrocarbons employed herein. Electrogenerated bromine is used

• −, ClO4−, HSO4−, Cl−, Br− [147]. General scheme of carboxylation of weak acidic hydrocarbons with electrogenerated bases. RH: weakly acidic hydrocarbon; BP: base precursor; EGB−: electrogenerated base; EGBH: conjugate acid of electrogenerated base [151]. Electrocarboxylation of N-methyldiglycolimide to

Visible light photoredox-catalyzed deoxygenation of alcohols

• Daniel Rackl,
• Viktor Kais,
• Peter Kreitmeier and
• Oliver Reiser

Beilstein J. Org. Chem. 2014, 10, 2157–2165, doi:10.3762/bjoc.10.223

• supply of hydrocarbons from fossil resources calls for the usage of renewable resources for the synthesis of fine chemicals in the future [1]. This strategy suffers from the relative high degree of functionalization of feedstock materials, which is often not desired in fine chemicals and further leads to

Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing

• Bradley D. Rose,
• Peter J. Santa Maria,
• Aaron G. Fix,
• Chris L. Vonnegut,
• Lev N. Zakharov,
• Sean R. Parkin and
• Michael M. Haley

Beilstein J. Org. Chem. 2014, 10, 2122–2130, doi:10.3762/bjoc.10.219

• conjugated hydrocarbons; Introduction Polycyclic conjugated hydrocarbons (PCHs) have been studied extensively due to the wide variety of physical properties that can be accessed by appropriate manipulation or “tuning” of a molecular scaffold (e.g., installation of donor/acceptor groups, inclusion of

Building complex carbon skeletons with ethynyl[2.2]paracyclophanes

• Ina Dix,
• Lidija Bondarenko,
• Peter G. Jones,
• Thomas Oeser and
• Henning Hopf

Beilstein J. Org. Chem. 2014, 10, 2013–2020, doi:10.3762/bjoc.10.209

• - (1), 1,3- (3), and 1,4-diethynylbenzene (5) (Scheme 1). These simple, flat molecules have been used extensively for the deliberate construction of larger polyaromatic hydrocarbons employing classical (e.g., Glaser coupling and its variants) or modern acetylenic coupling reactions (e.g., the

• Sonogashira coupling) [7]. For the smaller oligomers (dimers, trimers) the ortho-isomer with its opening angle of 60° between the ethynyl functions leads preferentially to (mono)cyclic hydrocarbons. For the meta-compound 3 we can expect both cyclic and acyclic (linear) products, and when the two ethynyl

• , phane hydrocarbons 4 and 6 correspond to 3 and 5. Clearly, in all cases employing 2, 4, and 6 as building blocks, the final structures will be layered. We have already used the pseudo-ortho-isomer 4 in two cases describing the preparation and structural properties of the (chiral) tetraynes 7 and 8

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• [43][48]. Solubility Surfactants Surfactant tails – fluorinated surfactants: Fluorine has a high electron affinity and electronegativity, hence fluorocarbons with a carbon number (n) that is equal to or greater than 4 have lower boiling points and refractive indices than the corresponding hydrocarbons

• [57] (different behaviour is observed when n < 4). Additionally, fluorocarbons have a larger molecular volume in the liquid state in comparison to corresponding hydrocarbons; therefore the polarizability per volume (α/υ) and the Hildebrand solubility parameter (δ, Equations 1) are significantly

• smaller than the equivalent hydrocarbons. The Hildebrand solubility parameter δ can be used as an indication of solubility of a substance, as it provides a quantifiable estimate of the degree of interaction between materials. The parameters in Equation 1 are enthalpy change through vaporisation (ΔHv), gas

Influence of perylenediimide–pyrene supramolecular interactions on the stability of DNA-based hybrids: Importance of electrostatic complementarity

• Christian B. Winiger,
• Simon M. Langenegger,
• Oleg Khorev and
• Robert Häner

Beilstein J. Org. Chem. 2014, 10, 1589–1595, doi:10.3762/bjoc.10.164

• -to-face stacking arrangement. Face-centered, parallel aromatic π–π stacking interactions have been studied and reviewed in great detail [1][2][3][4][5]. These interactions are especially important for polycyclic aromatic hydrocarbons (PAHs) [6][7]. The interaction is the result of solvophobicity, as

• molecular scaffold for arranging various types of chromophores [39][40][41][42][43][44]. Recently, we reported that oligoarenotides (oligomers with an alternating phosphodiester-aromatic hydrocarbon motif) exhibit similar structural properties as nucleic acids, and although the aromatic hydrocarbons cannot

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

• obtained spectra were analyzed using the Casa XPS (version 2.3.15, Casa software Ltd, Teignmouth/UK) software and were referenced to the C(1s)-peak of the saturated hydrocarbons by setting it to 285 eV. All measurements were carried out on silicon substrates. Atomic force microscopy (AFM): AFM images were

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

• in diethyl aryl phosphate with the AT reaction (yields from 76 to 96%), and then these phosphates were reduced to the corresponding aromatic hydrocarbons with moderate to good yields (10 to 83%). The phosphoramidate group can also be used to enhance the reactivity of an amine. This activation role of

The Ugi four-component reaction as a concise modular synthetic tool for photo-induced electron transfer donor-anthraquinone dyads

• Sarah Bay,
• Gamall Makhloufi,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 1006–1016, doi:10.3762/bjoc.10.100

• ]. This photo-induced electron transfer (PET) [30][31][32][33][34] has been investigated with donors such as porphyrines, polycyclic aromatic hydrocarbons, perylenediimides and (oligo)thiophenes [35][36], tetrathiafulvalenes [37], as well as phenothiazine and its derivatives [22][38][39][40]. The latter

Site-selective covalent functionalization at interior carbon atoms and on the rim of circumtrindene, a C₃₆H₁₂ open geodesic polyarene

• Hee Yeon Cho,
• Ronald B. M. Ansems and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2014, 10, 956–968, doi:10.3762/bjoc.10.94

• -like reactivity at its interior carbon atoms, whereas its edge carbons react like those of planar polycyclic aromatic hydrocarbons (PAHs). The Bingel–Hirsch and Prato reactions – two traditional methods for fullerene functionalization – afford derivatives of circumtrindene with one of the interior 6:6

• ]. Whereas fullerenes comprising complete three-dimensional polyhedra can be classified as “closed” geodesic polyarenes, curved subunits of fullerenes are regarded as “open” geodesic polyarenes [4]. The fullerenes constitute one family of geodesic polyarenes, and bowl-shaped polycyclic aromatic hydrocarbons

• functionalization of circumtrindene Since the isolation and characterization of the first polycyclic aromatic hydrocarbons in the 1800s, a tremendous range of chemical reactions on such compounds has been developed [41][42]. Most of this chemistry involves chemical modifications on the edge carbons and has been

Columnar/herringbone dual crystal packing of pyrenylsumanene and its photophysical properties

• Binod Babu Shrestha,
• Shuhei Higashibayashi and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2014, 10, 841–847, doi:10.3762/bjoc.10.80

• aromatic hydrocarbons – possess unique physical properties due to their curved π-conjugated systems [1][2][3][4][5]. One of these characteristic features is a columnar packing structure in the crystal state. Many buckybowls, including sumanene [2], exhibit columnar packing in which the bowl-shaped

Continuous flow nitration in miniaturized devices

• Amol A. Kulkarni

Beilstein J. Org. Chem. 2014, 10, 405–424, doi:10.3762/bjoc.10.38

New developments in gold-catalyzed manipulation of inactivated alkenes

• Michel Chiarucci and
• Marco Bandini

Beilstein J. Org. Chem. 2013, 9, 2586–2614, doi:10.3762/bjoc.9.294

• challenging metal-assisted nucleophilic manipulation of inactivated unsaturated hydrocarbons. Relative inertness of C=C with respect to alkynes or allenes accounts for this trend. In this scenario [Au(I)] and [Au(III)] catalysis is playing a major role leading to tremendous developments spanning from C

Bis(benzylamine) monomers: One-pot preparation and application in dendrimer scaffolds for removing pyrene from aqueous environments

• Olivia N. Monaco,
• Sarah C. Tomas,
• Meghan K. Kirrane and
• Amy M. Balija

Beilstein J. Org. Chem. 2013, 9, 2320–2327, doi:10.3762/bjoc.9.266

• hydrocarbons (PAHs) [23][24][25]. The presence of PAHs in drinking water is a growing concern due to their carcinogenic properties and persistence in the environment [26][27]. Current methods to remove these hydrocarbons are becoming ineffective. To examine the ability of the hybrid dendrimers to remove small

• synthesized. One application for these novel structures is the removal of polycyclic aromatic hydrocarbons, such as pyrene, from water. Upon exposure of an aqueous solution of pyrene to the thin dendrimer film, no significant difference in the pyrene fluorescence intensity was observed after 30 min for the

Continuous flow photocyclization of stilbenes – scalable synthesis of functionalized phenanthrenes and helicenes

• Quentin Lefebvre,
• Marc Jentsch and
• Magnus Rueping

Beilstein J. Org. Chem. 2013, 9, 1883–1890, doi:10.3762/bjoc.9.221

• backbone functionalized phenanthrenes and helicenes of various sizes in good yields. Keywords: continuous-flow reactor; flow chemistry; helicenes; light-driven cyclization reaction; photocyclization; stilbenes; Introduction Phenanthrenes are versatile intermediates toward polycyclic aromatic hydrocarbons

Self-assembly of 2,3-dihydroxycholestane steroids into supramolecular organogels as a soft template for the in-situ generation of silicate nanomaterials

• Valeria C. Edelsztein,
• Andrea S. Mac Cormack,
• Matías Ciarlantini and
• Pablo H. Di Chenna

Beilstein J. Org. Chem. 2013, 9, 1826–1836, doi:10.3762/bjoc.9.213

• -organogelator for hydrocarbons. The scope of solvent gelation was analysed with regard to two solvent parameters, namely the Kamlet–Taft and the Hansen solubility parameters. The best correlation was observed with the Hansen approach that revealed the existence of two clear gelation zones. We propose a general

• scope and thermal stability To assess the scope of the gelation ability of steroids 1–4 in a simple way, the test tube method was first used with 28 selected organic solvents ranging from hydrocarbons to alcohols (Table 1, entries 1–28). While steroids 2–4 were unable to gelate any of these solvents

• a cylindrical, almost linear profile, involves solvents with zero or very low δH and δp parameters and a δd parameter between 14 and 18 (hydrocarbons). Gelation zone B includes polar, non-protic solvents with higher dispersive interaction parameters δd (from 17.5 to 20). In contrast to the results