Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• as “reaction modifiers”, or metal ions (Cu, Pb) [72], polymers/surfactants [73] defined “catalyst modifiers”, whose common purpose is to decrease the hyperactivity of the (Pd) metal. It is clear that, besides the use and consumption of toxic/expensive substances, drawbacks in terms of catalyst reuse

Diels–Alder reactions of myrcene using intensified continuous-flow reactors

• Christian H. Hornung,
• Miguel Á. Álvarez-Diéguez,
• Thomas M. Kohl and
• John Tsanaktsidis

Beilstein J. Org. Chem. 2017, 13, 120–126, doi:10.3762/bjoc.13.15

• –Alder adduct of myrcene and acrylonitrile for the use as an odorant in the perfume industry [12]. A series of Diels–Alder reactions of myrcene (1) and another sesquiterpene, farnesene, with various dienophiles have been reported by Tabor et al. [13] for the use as solvents and surfactants. The emergence

• particular, the reaction of myrcene (1) with acrylic acid (2b) was investigated in detail, through batch and continuous-flow methods. The intensified flow process presents a more compact and efficient alternative to classic batch manufacture for the production of Diels–Alder adduct surfactants from myrcene

Formose reaction accelerated in aerosol-OT reverse micelles

• Makoto Masaoka,
• Tomohiro Michitaka and
• Akihito Hashidzume

Beilstein J. Org. Chem. 2016, 12, 2663–2667, doi:10.3762/bjoc.12.262

• (AOT), nonionic triton X-100 (TX), and cationic hexadecyltrimethylammonium bromide (CTAB) (Scheme 1). Before investigating the formose reaction, the sizes of water pools of the reverse micelles formed from the surfactants were evaluated under several conditions (see Supporting Information File 1). In

• observations, AOT provides the most efficient medium for the formose reaction among the surfactants examined in this study. The formose reaction in water pools of AOT reverse micelles were investigated at varying w and temperatures. Figure 2 shows time–conversion plots for AOT reverse micelles of different w

• investigated. The formose reaction in reverse micelles did not show the induction period, which is shown in the conventional formose reaction, indicating that the formation of glycolaldehyde was accelerated in the reverse micelles. AOT was the most effective among the surfactants examined. The values of

Interactions between cyclodextrins and cellular components: Towards greener medical applications?

• Loïc Leclercq

Beilstein J. Org. Chem. 2016, 12, 2644–2662, doi:10.3762/bjoc.12.261

• complexation of cholesterol, and iv) desorption of CD/cholesterol in the aqueous solution [83]. However, whatever the molecular mechanism, the lipid efflux mediated by CDs is clearly different from those of surfactants. Indeed, at low concentrations, the mechanism involves the penetration of the detergent

Isosorbide and dimethyl carbonate: a green match

• Fabio Aricò and
• Pietro Tundo

Beilstein J. Org. Chem. 2016, 12, 2256–2266, doi:10.3762/bjoc.12.218

• DURABIO® and PLANEXT®. Furthermore dimethyl isosorbide (DMI; bp 235 °C) [19], has found applications as potential substitute of high-boiling solvents (DMSO, DMF) and long chain aliphatic ester derivatives of isosorbide (mono- and disubstituted) have been investigated as surfactants [20]. However, it

Solvent-free synthesis of novel para-menthane-3,8-diol ester derivatives from citronellal using a polymer-supported scandium triflate catalyst

• Lubabalo Mafu,
• Ben Zeelie and
• Paul Watts

Beilstein J. Org. Chem. 2016, 12, 2046–2054, doi:10.3762/bjoc.12.193

• [6], acyl imidazoles or acyl ureas [7]. Acylation of alcohols in particular, provides a cheap and effective method for the synthesis of esters with potential applications in pharmaceutical products such as fragrances, flavours, surfactants or solvents [8][9]. Generally, these reactions are done in

From N-vinylpyrrolidone anions to modified paraffin-like oligomers via double alkylation with 1,8-dibromooctane: access to covalent networks and oligomeric amines for dye attachment

• Daniela Obels,
• Melanie Lievenbrück and
• Helmut Ritter

Beilstein J. Org. Chem. 2016, 12, 1395–1400, doi:10.3762/bjoc.12.133

• term paraffin means parum affinis or poor reactivity and comprises acyclic alkanes. They are obtained as byproducts in petroleum industry [28][29]. Technical derivatives are chloro- and chlorosulfonated paraffins which are used, e.g., as surfactants [30][31][32][33]. In the current paper we wish to

Cationic Pd(II)-catalyzed C–H activation/cross-coupling reactions at room temperature: synthetic and mechanistic studies

• Takashi Nishikata,
• Alexander R. Abela,
• Shenlin Huang and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2016, 12, 1040–1064, doi:10.3762/bjoc.12.99

• organic solvent, here 2 wt % solutions of selected surfactants in water were found to be excellent reaction media, providing an additional environmentally appealing feature to this protocol. While good yields could be obtained using the first generation surfactant PTS (polyoxyethanyl α-tocopheryl sebacate

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

• the type or density of hydrophobic groups [36][37]. Alternatively, similar control may be effected through additives exemplified by a range of molecular species, salts and surfactants [38][39][40]. Among such additives are cyclodextrins which can disrupt the interactions between hydrophobic

• surfactants based on poly(ethylene glycol) to recover the hydrophobic associations in hydrophobically substituted alkali-soluble emulsion (HASE) polymers complexed by α-CD and β-CD [41]. (It should be noted that association occurs between hydrophobically substituted polymers in aqueous solution and that this

• may be decreased by the addition of surfactants as shown by Prud’homme et al. for hydrophobically substituted hydroxyethyl cellulose [51].) Guo et al. showed that the addition of sodium dodecyl sulfate (SDS) to 2 wt % aqueous PAAodn in which the α-CD:n-C18H37 mole ratio is 2:1 to make the mole ratios

Synthesis of bi- and bis-1,2,3-triazoles by copper-catalyzed Huisgen cycloaddition: A family of valuable products by click chemistry

• Zhan-Jiang Zheng,
• Ding Wang,
• Zheng Xu and
• Li-Wen Xu

Beilstein J. Org. Chem. 2015, 11, 2557–2576, doi:10.3762/bjoc.11.276

• mild conditions without the Cu(І). Notably, the CuAAC reaction between the terminal alkyne of 36 and various azides provided the desired bistriazoles 37 in good yield (Scheme 14). Bistriazoles have potential application in the synthesis of surfactants after introducing the carbohydrate moiety. In 2012

• optimized reaction conditions. This provided the desired bistriazoles 40 in good yield (Scheme 15). It should be noted that the deprotection of bistriazoles 40 gives the gemini surfactants 41 (with two hydrophobic arms and two hydrophilic heads) in high yield. In 2012, Kaushik and co-workers prepared a

Aggregation behaviour of amphiphilic cyclodextrins: the nucleation stage by atomistic molecular dynamics simulations

• Giuseppina Raffaini,
• Antonino Mazzaglia and
• Fabio Ganazzoli

Beilstein J. Org. Chem. 2015, 11, 2459–2473, doi:10.3762/bjoc.11.267

• building blocks may affect the structure and stability of the larger aggregates. Some papers already reported simulation studies of CD aggregates, or better dimers, in water in the presence of hydrophobic or at least amphiphilic moieties, such as ionic [31] and non-ionic [32][33][34] surfactants assuming a

Preparation of Pickering emulsions through interfacial adsorption by soft cyclodextrin nanogels

• Shintaro Kawano,
• Toshiyuki Kida,
• Mitsuru Akashi,
• Hirofumi Sato,
• Motohiro Shizuma and
• Daisuke Ono

Beilstein J. Org. Chem. 2015, 11, 2355–2364, doi:10.3762/bjoc.11.257

• emulsion; Introduction Pickering emulsions, which are emulsions stabilized by colloidal particles instead of conventional low-molecular-weight surfactants [1], are formed through the adsorption of colloidal particles at an oil–water interface to give stable emulsion droplets. Particle adsorption, which

N-Alkyl derivatives of diosgenyl 2-amino-2-deoxy-β-D-glucopyranoside; synthesis and antimicrobial activity

• Agata Walczewska,
• Daria Grzywacz,
• Dorota Bednarczyk,
• Małgorzata Dawgul,
• Andrzej Nowacki,
• Wojciech Kamysz,
• Beata Liberek and
• Henryk Myszka

Beilstein J. Org. Chem. 2015, 11, 869–874, doi:10.3762/bjoc.11.97

• used as detergents, surfactants and emulsifiers. Moreover, they display a wide range of pharmacological activities, including antifungal, antiparasitic, antiinflammatory, antibacterial, and antitumor activities [2][3][4][5]. No wonder, saponins have been evaluated as vaccine adjuvants [6]. Despite the

Organic chemistry on surfaces: Direct cyclopropanation by dihalocarbene addition to vinyl terminated self-assembled monolayers (SAMs)

• Malgorzata Adamkiewicz,
• David O’Hagan and
• Georg Hähner

Beilstein J. Org. Chem. 2014, 10, 2897–2902, doi:10.3762/bjoc.10.307

• good evidence that this is less straightforward with functionalised surfactants [32]. Conclusion In summary we have been able to demonstrate that vinyl-terminated SAMs can be chemically modified by a range of dihalocarbenes to generate surfaces carrying the corresponding dihalocyclopropane motifs. The

Cyclodextrin-grafted polymers functionalized with phosphanes: a new tool for aqueous organometallic catalysis

• Jonathan Potier,
• Stéphane Menuel,
• David Mathiron,
• Véronique Bonnet,
• Frédéric Hapiot and
• Eric Monflier

Beilstein J. Org. Chem. 2014, 10, 2642–2648, doi:10.3762/bjoc.10.276

• supercritical CO2, ionic liquids or fluorous phases have been used to immobilize the organometallic catalyst [3][4][5]. Co-solvents, surfactants, amphiphilic phosphanes, molecular receptors, polymers or dispersed particles have also been investigated to favour contacts between the aqueous and the organic

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

• . Moreover, the concentration used has also a considerable influence on the mechanism. As examples at relatively low concentrations, the amphiphilic agents (surfactants) are membrane permeabilisers whereas at high concentrations, the penetration of these compounds in the cytoplasmic leads to protein

• aggregation [15]. It is worth mentioning that the additives may also have an effect on the biocidal activity (pH, surfactants, antioxidants, chelating agents, etc.) [16][17]. Moreover, some formulations contain mixtures of biocides in order to obtain additive or synergistic effects [18][19][20][21]. iii

• 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

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

• far been managed through the addition of soluble and self-assembling additives, such as surfactants and polymers [11][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51]. Viscosity of CO2 has been shown to be modifiable through the addition of aggregation and self

• -assembly of polymers and surfactants; however before internal/aggregated structures can be considered, and therefore viscosity modifiers developed, it is essential to ‘crack’ the puzzle of solubility, solvophilicity and CO2-philicity. Review Solvent compatibility – solubility and solvophilicity Solubility

• the solubility of commercially available surfactants in scCO2 showed that the majority are insoluble, with a few non-ionic surfactants showing marginal solubility (out of the 130 or so surfactants tested). Following this discovery efforts have been directed towards the development of CO2-soluble

The search for new amphiphiles: synthesis of a modular, high-throughput library

• George C. Feast,
• Thomas Lepitre,
• Xavier Mulet,
• Charlotte E. Conn,
• Oliver E. Hutt,
• G. Paul Savage and
• Calum J. Drummond

Beilstein J. Org. Chem. 2014, 10, 1578–1588, doi:10.3762/bjoc.10.163

• drugs as amphiphilic assemblies, sugar recognition and subsequent excretion should be reduced [40][41][42]. Sugar-based amphiphiles are often termed glycolipids and are also of interest for their use as ‘green’ surfactants in household cleaning products [43]. Previous work in this field has been

Bis(β-lactosyl)-[60]fullerene as novel class of glycolipids useful for the detection and the decontamination of biological toxins of the Ricinus communis family

• Hirofumi Dohi,
• Takeru Kanazawa,
• Akihiro Saito,
• Keita Sato,
• Hirotaka Uzawa,
• Yasuo Seto and
• Yoshihiro Nishida

Beilstein J. Org. Chem. 2014, 10, 1504–1512, doi:10.3762/bjoc.10.155

• mono- and bis(α-D-mannopyranosyl)-[60]fullerenes in both AFM (atomic force microscopy) and DLS analyses. Probably, the smaller particles are bilayer vesicles that are stable in DMSO and pyridine while they can be destructed in parts by treatment with surfactants such as Triton-X [25]. These nano-sized

Efficient synthesis of phenylene-ethynylene rods and their use as rigid spacers in divalent inhibitors

• Francesca Pertici,
• Norbert Varga,
• Arnoud van Duijn,
• Matias Rey-Carrizo,
• Anna Bernardi and
• Roland J. Pieters

Beilstein J. Org. Chem. 2013, 9, 215–222, doi:10.3762/bjoc.9.25

• rigid linkages between functional units. Examples of these have been reported in areas such as nanoelectronics and nanooptics [1], surfactants [2][3][4], photoelectrochemical detection [5], catalysis [6], glycosylation reactions [7], and carbohydrate–protein interactions [8]. Many different strategies

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

• autoclaving at 121 °C and 2 bar for 15 minutes. FTIR and NMR analyses before and after sterilisation show their stability and the absence of degradation [13]. In addition, they do not act as surfactants and can be easily dispersed in water. Nanosponges also have colloidal sizes with a mean diameter of less

• 2 mg of paclitaxel, thus confirming their wetting and solubilising properties towards paclitaxel avoiding the use of surfactants. The paclitaxel-loaded nanosponges formed a stable colloidal system in water inhibiting the recrystallization of paclitaxel over time. Moreover, this study demonstrated

Molecular solubilization of fullerene C₆₀ in water by γ-cyclodextrin thioethers

• Hai Ming Wang and
• Gerhard Wenz

Beilstein J. Org. Chem. 2012, 8, 1644–1651, doi:10.3762/bjoc.8.188

• hampered by the toxicities of the employed organic solvents or surfactants. The most successful strategy to carry the extremely hydrophobic C60 molecule into water is the use of appropriate water-soluble carriers that can form host–guest complexes, such as calixarenes [19][20] and cyclodextrins (CDs) [21

Similarity analysis, synthesis, and bioassay of antibacterial cyclic peptidomimetics

• Workalemahu M. Berhanu,
• Mohamed A. Ibrahim,
• Girinath G. Pillai,
• Alexander A. Oliferenko,
• Levan Khelashvili,
• Farukh Jabeen,
• Bushra Mirza,
• Farzana Latif Ansari,
• Ihsan ul-Haq,
• Said A. El-Feky and
• Alan R. Katritzky

Beilstein J. Org. Chem. 2012, 8, 1146–1160, doi:10.3762/bjoc.8.128

• associated with zinc cations and/or surfactants [30][31][32]. Anionic peptides bind with lysozyme, an important cationic hydrolytic enzyme. It is believed that the lysozyme opens the cell wall, “allowing a small anionic peptide to penetrate”. Topical administration of such anionic peptides is possible, for

Continuous preparation of carbon-nanotube-supported platinum catalysts in a flow reactor directly heated by electric current

• Alicja Schlange,
• Antonio Rodolfo dos Santos,
• Ulrich Kunz and
• Thomas Turek

Beilstein J. Org. Chem. 2011, 7, 1412–1420, doi:10.3762/bjoc.7.165

• average cluster size resulting in lower electrocatalytic activity, as reported by [21]. The microemulsion method allows for better control of the nanoparticle size and distribution in comparison to the impregnation method. Disadvantages of this method are the high cost of the used surfactants and their

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

• , in water instead of organic solvents is an obvious challenge that has been actively pursued [54][55][56][57] with water-soluble ruthenium catalysts [54], surfactants [58] and sonochemistry [59][60][61][62]. Using a low amount (0.083 mol %) of dendrimer, we have induced efficient olefin metathesis