Cyclodextrin-based nanosponges as drug carriers

• Francesco Trotta,
• Marco Zanetti and
• Roberta Cavalli

Beilstein J. Org. Chem. 2012, 8, 2091–2099, doi:10.3762/bjoc.8.235

• nanosponges have shown an ability to store large amounts of carbon dioxide, 1-methylcyclopropene and oxygen [8]. Three different cyclodextrin nanosponges were synthesised cross-linking α-, β- or γ-cyclodextrin with carbonyldiimidazole as oxygen-encapsulating formulations [50]. The nanosponges were able to

Flow photochemistry: Old light through new windows

• Jonathan P. Knowles,
• Luke D. Elliott and
• Kevin I. Booker-Milburn

Beilstein J. Org. Chem. 2012, 8, 2025–2052, doi:10.3762/bjoc.8.229

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

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

• 1.2) [74][75][76] can probably also be exploited to introduce other substituents than TMS. Thus the quenching of the corresponding carbanions with, e.g., carbon dioxide to produce carboxylic acid derivatives of conjugated bisallenes could be tried [83][138][144]. 2. Acyclic nonconjugated bisallenes

Metal–ligand multiple bonds as frustrated Lewis pairs for C–H functionalization

• Matthew T. Whited

Beilstein J. Org. Chem. 2012, 8, 1554–1563, doi:10.3762/bjoc.8.177

• were observed when carbon dioxide, carbonyl sulfide, and isocyanates were utilized, cleanly generating the Ir(I) carbonyl as a byproduct (Scheme 11) [71]. The nucleophilicity of the iridium center was demonstrated through a series of experiments. First, it was noted that the carbene complex does not

• ]. Single-crystal X-ray structure of a silver(I) triflate adduct of (PNP)Ir═C(H)Ot-Bu with most H atoms and phosphine substituents (except ipso carbon atoms) omitted for clarity. Heterolytic cleavage of H2 by a phosphine/borane FLP by H2 polarization in the P–B cavity [5][11]. Insertion of carbon dioxide

Photoreactions of cyclic sulfite esters: Evidence for diradical intermediates

• Rick C. White,
• Benny E. Arney Jr. and
• Heiko Ihmels

Beilstein J. Org. Chem. 2012, 8, 1208–1212, doi:10.3762/bjoc.8.134

• in the photochemistry of vicinal diaryloxiranes based on the photochemical formation of methyl ethers in methanol solution [8]. Mechanistically, stereoselective oxygen scrambling was found in the photoextrusion of carbon dioxide from benzyl benzoate esters [9]. Furthermore, photodecarboxylation

Chiral multifunctional thiourea-phosphine catalyzed asymmetric [3 + 2] annulation of Morita–Baylis–Hillman carbonates with maleimides

• Hong-Ping Deng,
• De Wang,
• Yin Wei and
• Min Shi

Beilstein J. Org. Chem. 2012, 8, 1098–1104, doi:10.3762/bjoc.8.121

• : phosphines attack the middle carbon atom of allenes to produce the 1,3-dipolar synthon (Scheme 1, reaction 1), and phosphines add to the β-position of MBH carbonate to remove carbon dioxide and tert-butanol, affording the 1,3-dipolar synthon (Scheme 1, reaction 2). Concerning the asymmetric [3 + 2

Functionalization of heterocyclic compounds using polyfunctional magnesium and zinc reagents

• Paul Knochel,
• Matthias A. Schade,
• Sebastian Bernhardt,
• Georg Manolikakes,
• Albrecht Metzger,
• Fabian M. Piller,
• Christoph J. Rohbogner and
• Marc Mosrin

Beilstein J. Org. Chem. 2011, 7, 1261–1277, doi:10.3762/bjoc.7.147

• has been shown to be of radical nature, and it affords the cross-coupling products in very short reaction times, often less than 5 min. 4 MgCl2-Enhanced reactivity of functionalized organozincs towards their addition to aldehydes, ketones and carbon dioxide The addition reactions of organometallic

• reagents to ketones, aldehydes and carbon dioxide are essential transformations in organic synthesis as they provide a convenient access to various types of alcohols or carboxylic acids. Usually, organozinc reagents only react with these types of electrophiles in the presence of catalytic amounts of

• transition metal salts and in a very limited scope. Recently, we showed that the cheap and non-toxic main group Lewis acid MgCl2 allows smooth addition reactions of different aromatic, heteroaromatic, alkyl and benzylic zinc reagents to various carbonyl derivatives and carbon dioxide without the use of polar

A practical microreactor for electrochemistry in flow

• Kevin Watts,
• William Gattrell and
• Thomas Wirth

Beilstein J. Org. Chem. 2011, 7, 1108–1114, doi:10.3762/bjoc.7.127

• 1,2-diphenylethane (7a) were obtained with the device depicted in Figure 1; the reactions are shown in Scheme 3. The Kolbe reaction did not seem to be a very suitable reaction for a flow reactor due to the large amount of carbon dioxide and hydrogen that is formed at the anode during the

• decarboxylation reaction. This was partially overcome by neutralising the solution with triethylamine as base, hence carbon dioxide gas was not liberated during the reaction [18]. The reactions were carried out in acetonitrile instead of methanol to reduce the amount of side-products that could be formed due to

Kinetic evaluation of the solvolysis of isobutyl chloro- and chlorothioformate esters

• Malcolm J. D’Souza,
• Matthew J. McAneny,
• Dennis N. Kevill,
• Jin Burm Kyong and
• Song Hee Choi

Beilstein J. Org. Chem. 2011, 7, 543–552, doi:10.3762/bjoc.7.62

• included a unimolecular fragmentation–ionization process with loss of carbon dioxide [5][6][11][12]. For 5, in nine of the more nucleophilic solvents the l/m ratio of 3.38 (Table 3) was a typical value for an addition–elimination (association–dissociation) mechanism [12]. We have proposed that neopentyl

Olefin metathesis in nano-sized systems

• Didier Astruc,
• Abdou K. Diallo,
• Sylvain Gatard,
• Liyuan Liang,
• Cátia Ornelas,
• Victor Martinez,
• Denise Méry and
• Jaime Ruiz

Beilstein J. Org. Chem. 2011, 7, 94–103, doi:10.3762/bjoc.7.13

• as possible and that polluting classic organic solvents be replaced by “greener” solvents such as water or super-critical carbon dioxide. Therefore during the last decade, we have attempted to make progress in this field with dendrimers using nano-organometallic chemistry [10]. There are several ways

Intramolecular hydroxycarbene C–H-insertion: The curious case of (o-methoxyphenyl)hydroxycarbene

• Dennis Gerbig,
• David Ley,
• Hans Peter Reisenauer and
• Peter R. Schreiner

Beilstein J. Org. Chem. 2010, 6, 1061–1069, doi:10.3762/bjoc.6.121

• regarding the nature of the fascinating [1,2]H-tunneling mechanism in phenylhydroxycarbenes (with parent 3, Scheme 1), we sought to study the behavior of derivatives of 3 in Ar matrices at temperatures as low as 11 K. We attempted to generate novel o-methoxy-substituted carbene 5 by extrusion of carbon

• dioxide from (o-methoxyphenyl)glyoxylic acid (6) by HVFP and subsequent condensation and isolation of the pyrolysis products in an excess of Ar (Scheme 3). However, neither 5 nor its tunneling product, o-anisaldehyde (7), could be detected: Comparison with an authentic spectrum of matrix-isolated 7 showed

Kinetics and mechanism of vanadium catalysed asymmetric cyanohydrin synthesis in propylene carbonate

• Michael North and
• Marta Omedes-Pujol

Beilstein J. Org. Chem. 2010, 6, 1043–1055, doi:10.3762/bjoc.6.119

• synthesis of hydrogen peroxide [71], and by the combination of these processes into a one-pot synthesis of propylene oxide from propene, hydrogen and oxygen [72][73]. In addition, it has been shown that in the presence of an appropriate catalyst, the reaction between epoxides and carbon dioxide can be

• achieved at atmospheric pressure and room temperature [74][75][76][77], or in a gas-phase continuous flow reactor [78], thus facilitating the use of waste carbon dioxide in this process [79]. In this paper we give full details of the use of catalyst 2 in propylene carbonate, and describe kinetic studies

Insights into the mechanical properties of a silicone oil gel with a ‘latent’ gelator, 1-octadecylamine, and CO₂ as an ‘activator’

• Emiliano Carretti,
• Mathew George and
• Richard G. Weiss

Beilstein J. Org. Chem. 2010, 6, 984–991, doi:10.3762/bjoc.6.111

• , DE 19711, USA 10.3762/bjoc.6.111 Abstract A detailed study of the rheological properties of silicone oil gels, made from a low-molecular-mass organic gelator, a combination of 1-octadecylamine (a latent gelator) and carbon dioxide (an ‘activating’ molecule), is reported. Information gleaned from the

• triatomic gas [8][9], especially carbon dioxide [10][11], is added). Although the structures of SAFINs and rheological properties of their gels made with ‘normal’ LMOGs have been extensively investigated [2][12], the mechanical properties of gels made from latent LMOGs have not received much attention

• LMOG, 1-octadecylamine (ODA), and a triatomic molecular ‘activator’, carbon dioxide, with silicone oil, tetramethyltetraphenyltrisiloxane, as the liquid component [10][11]. This liquid has been selected because its very low vapor pressure avoids a potential complication, i.e., evaporation of a portion

Functionalized copolyimide membranes for the separation of gaseous and liquid mixtures

• Nadine Schmeling,
• Roman Konietzny,
• Daniel Sieffert,
• Patrick Rölling and
• Claudia Staudt

Beilstein J. Org. Chem. 2010, 6, 789–800, doi:10.3762/bjoc.6.86

• market currently has a steady growth of approximately 10–15% each year [3]. Membrane based separations of gaseous mixtures have been well established for natural gas treatments (removal of carbon dioxide), for hydrogen removal (e.g. in cracking processes) for oxygen enrichment from air (medical devices

• new, economic and reliable membrane materials. In the following section, three examples of new applications, namely, the separation of gaseous olefin/paraffin mixtures, aromatic/aliphatic separation and the removal of carbon dioxide from natural gas a with high CO2 content, are discussed in detail

Pd-catalyzed decarboxylative Heck vinylation of 2-nitrobenzoates in the presence of CuF₂

• Lukas J. Gooßen,
• Bettina Zimmermann and
• Thomas Knauber

Beilstein J. Org. Chem. 2010, 6, No. 43, doi:10.3762/bjoc.6.43

• acids is disclosed. In the presence of a catalyst system generated in situ from Pd(OAc)2 (2 mol %), CuF2 (2 equiv), and benzoquinone (0.5 equiv) in NMP, a wide range of olefins were coupled with various 2-nitrobenzoates at 130 °C with the release of carbon dioxide to afford the corresponding vinyl

Asymmetric reactions in continuous flow

• Xiao Yin Mak,
• Paola Laurino and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19

• conditions as well as in supercritical carbon dioxide (scCO2), as means of creating a more ‘environmentally-friendly’ process [45]. Under the solventless or scCO2 flow conditions, the productivity of the catalyst was observed to be much higher. The use of supercritical fluids, in particular scCO2, as an

• was reduced using a cinchonidine-modified Pt/Al2O3 catalyst in a fixed bed reactor in both supercritical carbon dioxide and ethane [47]. Poliakoff and co-workers have investigated the continuous asymmetric hydrogenation of dimethyl itaconate in scCO2 [48][49]. By using the catalyst [Rh(COD)2(nbd