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

The preparation of several 1,2,3,4,5-functionalized cyclopentane derivatives

• André S. Kelch,
• Peter G. Jones,
• Ina Dix and
• Henning Hopf

Beilstein J. Org. Chem. 2013, 9, 1705–1712, doi:10.3762/bjoc.9.195

• Braunschweig, Germany Novartis Pharma AG, CH-4056 Basel, Switzerland 10.3762/bjoc.9.195 Abstract With the goal of eventually synthesizing [5]radialene (3), the still missing member of the parent radialene hydrocarbons, we have prepared the pentaacetates 21 and 31, the pentabromide 29 and the hexabromide 32

• . In principle these should be convertible by elimination reactions to the desired target molecule. Keywords: bromination; cyclopentanes; esterification; permethylcyclopentadiene; polyfunctional compounds; radialenes; Introduction Radialenes are cyclic cross-conjugated hydrocarbons that consist

• derivatives bearing alkyl and aryl and also functionalized substituents, beginning with 1 and ending with [6]radialene (4, Scheme 1) are known for the whole series [2][3][4][5], among the parent hydrocarbons one representative is still missing: [5]radialene (3). One reason for this absence is certainly the

Bromination of hydrocarbons with CBr₄, initiated by light-emitting diode irradiation

• Yuta Nishina,
• Bunsho Ohtani and
• Kotaro Kikushima

Beilstein J. Org. Chem. 2013, 9, 1663–1667, doi:10.3762/bjoc.9.190

• Yuta Nishina Bunsho Ohtani Kotaro Kikushima Research Core for Interdisciplinary Science, Okayama University, Tsushimanaka, Kita-ku, Okayama 700-8530, Japan Catalysis Research Center, Hokkaido University, Sapporo 001-0021, Japan 10.3762/bjoc.9.190 Abstract The bromination of hydrocarbons with CBr4

• hydrocarbons proceeds through radical abstraction of hydrogen atoms and trapping with bromide, whereas the bromination reactions of aromatic and unsaturated hydrocarbons are induced by electrophilic addition of bromine and/or a cationic bromide. Combinations of N-bromosuccinimide (NBS) with

• reported to serve as bromine sources for the bromination of saturated hydrocarbons, these reactions exhibit low selectivity or reactivity. Efficient bromination using Br2 as a bromine source combined with a stoichiometric base [24], an excess of MnO2 [25], or a catalytic amount of Li2MnO3 [26] has been

True and masked three-coordinate T-shaped platinum(II) intermediates

• Manuel A. Ortuño,
• Salvador Conejero and
• Agustí Lledós

Beilstein J. Org. Chem. 2013, 9, 1352–1382, doi:10.3762/bjoc.9.153

• (pyrazolyl)borate; n = 0, 1) produces a transient three-coordinate Pt(II) complex [Pt(R)(η2-N3)]n+ 10 (Scheme 10), which is able to activate C–H bonds of hydrocarbons or form solvent adducts [103][104][105]. Solution behavior In masked three-coordinate d8 complexes, the fourth coordination site is occupied

Metal-free aerobic oxidations mediated by N-hydroxyphthalimide. A concise review

• Lucio Melone and
• Carlo Punta

Beilstein J. Org. Chem. 2013, 9, 1296–1310, doi:10.3762/bjoc.9.146

• complexes. However, eco-friendly standards, including the demand for highly selective transformations, impose the development of metal-free processes, especially for large-scale productions, as in the case of the oxygenation of hydrocarbons. For this reason, many efforts have been devoted in the past decade

• processes, especially in the field of the selective oxygenation of hydrocarbons. Review Radical initiation by thermal decomposition Thermal decomposition of peroxides and azo-compounds is a well-known technique generally used to generate radicals in solution. Ishii and co-workers widely investigated the key

• zeolite, for the oxygenation of a wider range of hydrocarbons [34]. Moreover, the electronic effect of substituents on quinones and on the aromatic ring of NHPI was also investigated. Quinones bearing halogen groups were used in the selective oxidation of alkylarenes, alkenes and alkanes [35], revealing

3D-printed devices for continuous-flow organic chemistry

• Vincenza Dragone,
• Victor Sans,
• Mali H. Rosnes,
• Philip J. Kitson and
• Leroy Cronin

Beilstein J. Org. Chem. 2013, 9, 951–959, doi:10.3762/bjoc.9.109

• chemical properties; however their chemical compatibility is low. In fact they are not generally recommended for exposure to alcohol, glycols, alkalis, brake fluids, or to chlorinated or aromatic hydrocarbons [20]. Therefore, PP was the plastic of choice for the device fabrication. The shape of the 3D

Intramolecular carbolithiation cascades as a route to a highly strained carbocyclic framework: competition between 5-exo-trig ring closure and proton transfer

• William F. Bailey and
• Justin D. Fair

Beilstein J. Org. Chem. 2013, 9, 537–543, doi:10.3762/bjoc.9.59

• temperature. Keywords: carbolithiation cascade; carbometallation; intramolecular carbolithiation; intermolecular proton transfer; lithium–halogen exchange; strained hydrocarbons; Introduction The first publication describing an intramolecular carbolithiation appeared in 1968: Drozd and co-workers reported

A new intermediate in the Prins reaction

• Shinichi Yamabe,
• Takeshi Fukuda and
• Shoko Yamazaki

Beilstein J. Org. Chem. 2013, 9, 476–485, doi:10.3762/bjoc.9.51

• produced when pinene (a bicyclic monoterpene) was heated with paraformaldehyde. However, Prins performed the first rather comprehensive study of the reactions between formaldehyde and hydrocarbons with C=C double bonds [2][3]. These were styrene, pinene, camphene and anethole. As a catalyst, sulfuric acid

Polar reactions of acyclic conjugated bisallenes

• Reiner Stamm and
• Henning Hopf

Beilstein J. Org. Chem. 2013, 9, 36–48, doi:10.3762/bjoc.9.5

• the reaction products. Although this goal was accomplished, the overall process is considerably more complex (Scheme 3). Treatment of 2 or 4 in THF at −35 °C with 13 resulted in the formation of four hydrocarbons: two monoallylated products, 14 and 17, and two bisallylated ones, 19 and 20, with the

• pure form by preparative gas chromatography. All hydrocarbons are colorless oils that, even at −15 °C (deep freeze), are stable for a limited time only. A simple rationalization of the product formation, in which 14 and 17 are the primary products, is given in Scheme 3. Hydrocarbon 14 is the direct

• , and co-workers [21][22][23][24] are particular noteworthy in the present context. The French authors demonstrated that vinylallenes, hydrocarbons rather similar to the systems studied here, provide cyclopentenone derivatives in a process mimicking the Nazarov cyclization [25]. The first conjugated

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

• steps (high step economy). Keywords: alicyclic; bisallenes; cyclic; cycloadditions; cycloisomerization; isomerization; molecular complexity; step economy; Table of Contents Introduction Review Acyclic conjugated bisallenes 1.1 Synthesis of hydrocarbons 1.2 Synthesis of functionalized systems 1.3

• heteroaromatic moieties may take over the role of the aromatic core. Review 1 Acyclic conjugated bisallenes 1.1 Synthesis of hydrocarbons Bisallenes of type 2 or 6 have been prepared by many different routes and strategies from which, however, three stand out: i) The C6-carbon framework may be constructed by

• ’-reactions, but detailed mechanistic experiments have not been undertaken for this particular reaction so far [21]. The two C6H6-isomers 2 and 21 are produced in ca. 2:3 ratio and the total yield varies from 40–70%, depending primarily on the workup conditions. The separation of the two hydrocarbons by

Volatile organic compounds produced by the phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria 85-10

• Teresa Weise,
• Marco Kai,
• Anja Gummesson,
• Armin Troeger,
• Stephan von Reuß,
• Silvia Piepenborn,
• Francine Kosterka,
• Martin Sklorz,
• Ralf Zimmermann,
• Wittko Francke and
• Birgit Piechulla

Beilstein J. Org. Chem. 2012, 8, 579–596, doi:10.3762/bjoc.8.65

• (38) (small amounts of which were found to be present among the natural volatiles), retention indices with methylketones as reference standards were calculated. Corresponding data published for methyl-branched hydrocarbons and increment calculations strongly suggested iso-branching for the main