Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

• Periklis X. Kolagkis,
• Eirini M. Galathri and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

• surfactants with SiO2, thus, eliminating the drawback of poor recyclability exhibited by the surfactants [118]. Various different Lewis acid surfactants were screened for their catalytic activity in the synthesis of BIMs with the combination of AlCl3∙6H2O as the Lewis acid, sodium dodecyl sulfate (SDS) as the

• greatly diminished the conversion rates of BIMs, while replacing SDS with different surfactants had no effect on the reaction profile. Even though a large amount of 0.5 g of the LASSC nanocatalyst was employed, it displayed impressive stability, since it could be retrieved and reused upwards of 11 times

• research group [126]. Kaur et al. synthesized various CdS nanostructures with differences in their morphology and screened them for their catalytic potential, while avoiding the use of surfactants, which were too difficult to remove from the reaction mixture (Scheme 24). CdS_3a which was a porous and

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• of surfactants, which are also called emulsifiers within the first few minutes [26]. Emulsifiers such as sodium lauryl sulfate, sodium or potassium salts of fatty acids (soaps), salts of alkylbenzene sulfonates, and O-polyoxyethyleneated long-chain alcohols are used to change the two incompatible

• product can be used as is and does not generally need to be altered or processed. Drawbacks of emulsion polymerization include residual surfactants, significant chain transfer to polymer, and difficulty to dry polymers. 1.3 Reversible deactivation radical polymerization A key drawback of conventional

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

• Naoya Oku,
• Saki Hayashi,
• Yuji Yamaguchi,
• Hiroyuki Takenaka and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2023, 19, 133–138, doi:10.3762/bjoc.19.13

• , phylum Pteridophyta) [29]. Monoacylglycerols are non-ionic surfactants derivable by hydrolysis of fat, and exhibit antibacterial [30], antifungal [30], antiviral [31], and antiprotozoal [32] activities. Due to these useful properties, they have found a wide range of industrial applications as emulsifiers

Preparation of β-cyclodextrin/polysaccharide foams using saponin

• Max Petitjean and
• José Ramón Isasi

Beilstein J. Org. Chem. 2023, 19, 78–88, doi:10.3762/bjoc.19.7

• ]. Saponins, because of their amphiphilic nature, are known as natural surfactants [9]. They have been used as natural detergents, foaming agents, stabilizers, emulsifiers and wetting agents, for example [10]. The micelles produced will be different in size and shape as a function of the type of saponin

• , their aglycone forms but also the number of sugar molecules involved [11]. They can be found in beverage emulsions [12], and as food surfactants [13], because they are useful also to prevent the development of virus or bacteria in food or beverages [14][15]. As for medical purposes, it has been reported

Synthesis of new bile acid-fused tetrazoles using the Schmidt reaction

• Dušan Đ. Škorić,
• Olivera R. Klisurić,
• Dimitar S. Jakimov,
• Marija N. Sakač and
• János J. Csanádi

Beilstein J. Org. Chem. 2021, 17, 2611–2620, doi:10.3762/bjoc.17.174

• selective activity towards certain tumor cell lines. Keywords: antiproliferative activity; Schmidt reaction; steroids; tetrazoles; trimethylsilyl azide; Introduction Bile acids are naturally occurring steroidal surfactants that play various biological roles. Besides the well-known role as lipid

Synthesis and physicochemical evaluation of fluorinated lipopeptide precursors of ligands for microbubble targeting

• Masayori Hagimori,
• Estefanía E. Mendoza-Ortega and
• Marie Pierre Krafft

Beilstein J. Org. Chem. 2021, 17, 511–518, doi:10.3762/bjoc.17.45

• -surfactants to the phospholipid molecules of the MB shell and strongly reduce its interfacial tension [35][36]. Recent studies have reported that the fluorine–fluorine interactions that develop between the FC and the MB shell component (e.g., fluorinated biomarkers [37] and fluorinated nanoparticles

• that of 3, and not intermediate, as it could have been expected. It may possibly be that this comportment can be ascribed to odd/even effects, which are known to impact on the adsorption process of surfactants [43]. For example, surfactants with an odd number of carbon atoms in their alkyl chain were

Dirhamnolipid ester – formation of reverse wormlike micelles in a binary (primerless) system

• David Liese,
• Hans Henning Wenk,
• Xin Lu,
• Jochen Kleinen and
• Gebhard Haberhauer

Beilstein J. Org. Chem. 2020, 16, 2820–2830, doi:10.3762/bjoc.16.232

• interaction of the alkyl chains. Keywords: dirhamnolipid ester; gemini surfactant; rheology; reverse wormlike micelle (RWLM); Introduction Surfactants have both hydrophilic and hydrophobic groups and are therefore amphiphilic molecules. Due to their unique molecular structure, surfactants are essential

• environmentally friendly biosurfactants because they are 100% biodegradable and are more compatible with water organisms than traditional surfactants. In solution, surfactants self-assemble into micelles with different shapes (spherical, cylindrical, double layer, etc.). In aqueous solution, the surfactant

• hydrophobic groups are oriented towards the solvent. One structure which can be formed by surfactants are so-called wormlike micelles, that are characterized by a high anisotropic structure. These micelles can, if the concentration and dynamics of the surfactant micelles is right, build viscosity since the

Easy access to a carbohydrate-based template for stimuli-responsive surfactants

• Thomas Holmstrøm,
• Daniel Raydan and
• Christian Marcus Pedersen

Beilstein J. Org. Chem. 2020, 16, 2788–2794, doi:10.3762/bjoc.16.229

• anomeric mixture of the building block was used for the synthesis of a molecule that could act as an emulsifier only in the presence of Zn2+ ions. Keywords: carbohydrates; emulsifiers; stimuli-responsive; surfactants; synthesis; Introduction Surfactants (surface-active agents) are molecules with both a

• hydrophilic and a lipophilic domain, thereby rendering them amphiphilic. This dual functionality gives surfactants unique properties such as being able to stabilize emulsions (emulsifiers) or forming large self-assembled aggregates that can take the shape of, for example, micelles or liposomes [1]. The latter

• surfactants: amphiphilic molecules that can alter their properties upon an external stimulus [6]. The intelligent surfactants are not passive but designed to undergo a molecular change when it is triggered with either a change in the pH value [7][8], upon light irradiation [9] or in the presence of metal ions

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Host–guest interactions between p-sulfonatocalix[4]arene and p-sulfonatothiacalix[4]arene and group IA, IIA and f-block metal cations: a DFT/SMD study

• Valya K. Nikolova,
• Cristina V. Kirkova,
• Silvia E. Angelova and
• Todor M. Dudev

Beilstein J. Org. Chem. 2019, 15, 1321–1330, doi:10.3762/bjoc.15.131

• ligands with novel features. They have found various applications in chemical [5], analytical [6][7][8][9], and engineering materials fields (self-assembling monolayers, surfactants, sensors [10][11]), in polymer synthesis [12][13], controlled drug-delivery systems [14], and so on, besides the biochemical

Towards the preparation of synthetic outer membrane vesicle models with micromolar affinity to wheat germ agglutinin using a dialkyl thioglycoside

• Dimitri Fayolle,
• Nathalie Berthet,
• Bastien Doumeche,
• Olivier Renaudet,
• Peter Strazewski and
• Michele Fiore

Beilstein J. Org. Chem. 2019, 15, 937–946, doi:10.3762/bjoc.15.90

• Fisher reaction between pyranoses and fatty alcohols of different lengths [8][9]. Alkyl thioglycosides are known for their properties as co-surfactants [10] and present interesting antimicrobial activities [11], acting as glycosidase inhibitors and being resistant towards glycoside hydrolases [12][13

Easy, efficient and versatile one-pot synthesis of Janus-type-substituted fullerenols

• Marius Kunkel and
• Sebastian Polarz

Beilstein J. Org. Chem. 2019, 15, 901–905, doi:10.3762/bjoc.15.87

• with ESIMS, TGA and MAS NMR. These compounds can serve as precursors for further modified fullerenols or as true surfactants. Characterization of fullerenol amphiphile with substituent 1. a) ESIMS in positive mode, molecular ion peak marked with circle, b) TGA under nitrogen with 5 K/min, c) MAS-NMR

Ammonium-tagged ruthenium-based catalysts for olefin metathesis in aqueous media under ultrasound and microwave irradiation

• Łukasz Gułajski,
• Andrzej Tracz,
• Katarzyna Urbaniak,
• Stefan J. Czarnocki,
• Michał Bieniek and
• Tomasz K. Olszewski

Beilstein J. Org. Chem. 2019, 15, 160–166, doi:10.3762/bjoc.15.16

• in the flourishing field of micellar catalysis and the use of surfactants that self-aggregate in water into micelles in which the hydrophobic core provides an environment for effecting homogeneous reactions between organic molecules has been reviewed by Scarso et al. [40] and very recently by

Fabrication of supramolecular cyclodextrin–fullerene nonwovens by electrospinning

• Hiroaki Yoshida,
• Ken Kikuta and
• Toshiyuki Kida

Beilstein J. Org. Chem. 2019, 15, 89–95, doi:10.3762/bjoc.15.10

• gemini surfactants [7], diphenylalanine [8], cyclodextrin (CD)/CD derivatives [9][10][11][12], heteroditopic monomers [13], and self-assembling oligopeptides [14] have been successfully electrospun to produce continuous fibers. Among these molecules, CD is a unique compound that can form fibers despite

• abilities for free radical scavengers and solar cell applications [18][19][20]. A serious issue for practical applications of fullerenes is the poor solubility in most solvents. Various methods to improve the solubility have been demonstrated by coating the surface with surfactants or host molecules and

Green synthesis of new chiral 1-(arylamino)imidazo[2,1-a]isoindole-2,5-diones from the corresponding α-amino acid arylhydrazides in aqueous medium

• Nadia Bouzayani,
• Jamil Kraїem,
• Sylvain Marque,
• Yakdhane Kacem,
• Abel Carlin-Sinclair,
• Jérôme Marrot and
• Béchir Ben Hassine

Beilstein J. Org. Chem. 2018, 14, 2923–2930, doi:10.3762/bjoc.14.271

• surfactants that can form micelles with a hydrophobic core and a hydrophilic corona. (iii) This clean method afforded compounds 5a–m without the need of additional purification such as column chromatography or recrystallization. (iv) The use of a sealed tube [36][37][38][39][40][41][42][43] obeys to four out

Synthesis of a tyrosinase inhibitor by consecutive ethenolysis and cross-metathesis of crude cashew nutshell liquid

• Jacqueline Pollini,
• Valentina Bragoni and
• Lukas J. Gooßen

Beilstein J. Org. Chem. 2018, 14, 2737–2744, doi:10.3762/bjoc.14.252

• properties and industrial applications, for instance in surfactants, plasticizers, resins, soft materials and diverse medical applications [7]. Isolated via cold-press or solvent extraction processes, it contains predominantly anacardic acid (1). Upon distillation or any other thermal treatment, anacardic

• ][10]. These include aromatic amines as polymers [11][12], cardanol-based phosphates as modifiers for epoxy resins [13], cardanol grafted natural rubber as rubber plasticizers [14], amine-based surfactants [15] and phenol/cardanol-formaldehyde based adhesives [16]. The chemical valorization of

Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

• Vladimir A. Burilov,
• Guzaliya A. Fatikhova,
• Mariya N. Dokuchaeva,
• Ramil I. Nugmanov,
• Diana A. Mironova,
• Pavel V. Dorovatovskii,
• Victor N. Khrustalev,
• Svetlana E. Solovieva and
• Igor S. Antipin

Beilstein J. Org. Chem. 2018, 14, 1980–1993, doi:10.3762/bjoc.14.173

• surfactants having a host–guest recognition site [23]. So, they are able to form nanoaggregates in aqueous solutions, thus providing the concentration of the active binding sites into nanoaggregate for multivalent binding with the substrate [24]. We recently synthesized a series of cationic receptors based on

• are assigned to the different natures of the used dyes. In the case of EY, which is a dianion at pH 7, the interaction with the dicationic calixarenes 10a,b results in the formation of a non-charged complex, which can be referred to a non-ionic surfactant. Generally, non-ionic surfactants possess

• compared with the less hydrophobic 10a,b. A similar trend (decrease of about two orders) was observed for the CAC of gemini surfactants possessing two hydrophobic alkyl tails in comparison with ordinary ones having one alkyl tail [44]. Additionally, the aggregation properties were investigated by dynamic

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• section we will discuss the utility of some of the well-established catalytic nanoreactors towards green(er) chemistry [62]. 2.1. Micelles Micelles are supramolecular architectures that are assembled of amphiphilic molecules [41]. Above the critical micellar concentration (CMC), surfactants with the

• stabilized by colloidal particles that adsorb at the water–oil interface. They are more stable than classical emulsions and do not require the usage of small molecule surfactants. This is a big advantage in downstream processing and product and catalyst recovery. The enzyme Candida antarctica lipase B (CalB

Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry

• Katharina Hiebler,
• Georg J. Lichtenegger,
• Manuel C. Maier,
• Eun Sung Park,
• Renie Gonzales-Groom,
• Bernard P. Binks and
• Heidrun Gruber-Woelfler

Beilstein J. Org. Chem. 2018, 14, 648–658, doi:10.3762/bjoc.14.52

• . Traditionally, emulsions have been kinetically stabilised by molecular species including surfactants, polymers or proteins all of which possess water-liking groups and oil-liking groups enabling them to adsorb to freshly created oil–water interfaces preventing to some extent coalescence between neighbouring

• surfactants as emulsifier. Densely packed catalyst particles around oil drops can be seen in Figure 10 enabling high stability. Similar trends in behaviour are also found in toluene-in-water emulsions, Figure 11. Conclusion In this work we present a set of heterogeneous Ce–Sn–Pd oxide catalysts that can be

Electrophilic trifluoromethylselenolation of terminal alkynes with Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate

• Clément Ghiazza,
• Anis Tlili and
• Thierry Billard

Beilstein J. Org. Chem. 2017, 13, 2626–2630, doi:10.3762/bjoc.13.260

• (Scheme 3). The expected products were obtained with good yields. The tridecafluorohexylselenyl group in product 5a makes this compound interesting because it opens the way to applications in the design of fluorinated polymers or surfactants. Conclusion To conclude, Se-(trifluoromethyl) 4

An efficient synthesis of a C₁₂-higher sugar aminoalditol

• Łukasz Szyszka,
• Anna Osuch-Kwiatkowska,
• Mykhaylo A. Potopnyk and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2017, 13, 2146–2152, doi:10.3762/bjoc.13.213

• which could eventually be used in the synthesis of macrocyclic derivatives. Sucrose, undoubtedly the most common disaccharide, has found applications in the synthesis of polymers [17] or surfactants [18]. There is also an increasing interest in the application of sucrose as a ‘normal’ chemical [16][19

An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation

• Carolina S. García,
• Paula M. Uberman and
• Sandra E. Martín

Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166

• to the limited solubility of the reactants, leading to less efficient reactions. To solve this problem several systems have been developed by using co-solvents, surfactants, pressure reactors or heating the reaction mixture by MW irradiation [44]. Under MW irradiation conditions, not only the rate of

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• -surfactants, if available via prebiotic syntheses [20][60][61][62], could have also contributed to the formation of primitive amphiphile-based structures, by allowing structure stabilization under prebiotic conditions, e.g., high ionic strength or temperature or stringent pH values. Selective association of

• composed of several types of “prebiotic” fatty acids and co-surfactants. That is, the vesicles could have retained the primer/template system while activated monomers crossed the vesicle bilayers by passive diffusion. Similarly, amino acids could be dimerized within vesicles [86]. In related experiments

Mechanochemistry-assisted synthesis of hierarchical porous carbons applied as supercapacitors

• Desirée Leistenschneider,
• Nicolas Jäckel,
• Felix Hippauf,
• Volker Presser and
• Lars Borchardt

Beilstein J. Org. Chem. 2017, 13, 1332–1341, doi:10.3762/bjoc.13.130

• designing the porosity of carbon materials involves hard or soft templates [22][23][24]. Hard-templating utilizes metal oxide nanoparticles [25] and salts [26][27][28], which have to be synthesized in advance. Soft-templating employs surfactants or other structure-directing molecules, which self-assemble to

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• average particle size, distribution and shape. Different kinds of samples beside soluble proteins can be studied by this technique including nucleic acids, protein-based complexes, lipids, membrane proteins and surfactants, glycoproteins, virus, polymers and colloids [78][79]. Proteins: SAXS applied to