pH- and concentration-dependent supramolecular self-assembly of a naturally occurring octapeptide

• Goutam Ghosh and
• Gustavo Fernández

Beilstein J. Org. Chem. 2020, 16, 2017–2025, doi:10.3762/bjoc.16.168

• + moieties. AFM studies at pH 5.5 showed the formation of nanoparticle assemblies, which is in agreement with the loss of the secondary structure (Figure 3b). Similarly, at pH 2.2, PEP-1 also exhibited a structureless CD spectrum and irregular nanostructures (Figure S4, Supporting Information File 1). In

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• subsequently cross-linked by oxidative homocoupling to form a highly cross-linked polymer [138]. Zhang and co-workers recently demonstrated that the dispersibility of polymer nanoparticle-supported benzothiadiazole photocatalysts could be improved in a range of different solvents by copolymerising classical

• solubility of the photocatalyst being poor in those solvents [139]. 2.4 Solid-supported semiconductors and metal nanoparticles For the same reasons outlined in the previous section, the immobilisation of thin films of semiconductors and the deposition of metal nanoparticle photocatalysts can improve the

• 2.1 and 2.2, and can be explored in detail in independent reviews [1][6][176][181][182]. Some examples are more unique, such as metal nanoparticle (NPs) photocatalysis. Despite having a conductor band structure,and therefore no band gap, the nanoscale of these materials produces visible light

The reaction of arylmethyl isocyanides and arylmethylamines with xanthate esters: a facile and unexpected synthesis of carbamothioates

• Narasimhamurthy Rajeev,
• Toreshettahally R. Swaroop,
• Ahmad I. Alrawashdeh,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Seegehalli M. Anil,
• Kuppalli R. Kiran,
• Chandra,
• Paris E. Georghiou,
• Kanchugarakoppal S. Rangappa and
• Maralinganadoddi P. Sadashiva

Beilstein J. Org. Chem. 2020, 16, 159–167, doi:10.3762/bjoc.16.18

• ], iron nanoparticle-catalyzed reactions of 2-naphthol with benzaldehyde and some of its derivatives with thiourea [22], isothiocyanato oxindoles with ketones [23], ammonium isothiocyanates with chalcones [24], and α-isothiocyanato esters with α-keto amides [25]. Among the synthetic methods available for

Synthesis of 3-alkenylindoles through regioselective C–H alkenylation of indoles by a ruthenium nanocatalyst

• Abhijit Paul,
• Debnath Chatterjee,
• Srirupa Banerjee and
• Somnath Yadav

Beilstein J. Org. Chem. 2020, 16, 140–148, doi:10.3762/bjoc.16.16

• explored, with some favourable results [35][36][37][38][39][40]. Other very important aspects of Ru catalysts are mechanistic aspects, which has also favoured their exploration for directing group-assisted C–H activation reactions [40]. With respect to non-directed Ru nanoparticle-catalysed reactions

• , there are few reports. For example, the supported Ru-catalysed regiospecific C(sp2)–H arylation of benzo[h]quinolines and the addition of vinylsilanes to the C–H bonds of α-tetralones were reported by Inoue and co-workers [41][42]. Pieters et al. reported the Ru nanoparticle-catalysed C–H deuteration

• reaction of aza compounds [43][44]. Again, a Ru nanoparticle-catalysed C–H selenylation of indoles was reported by Lin et al. [45]. Herein, we report the Ru-catalysed regioselective synthesis of C3 alkenylindoles using a near-naked, surfactant-free, and recyclable Ru nanocatalyst in a heterogeneous manner

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• electrohydrogenation of 12b that resulted in improved yield and enantiomeric purity as compared to previously reported methods (Scheme 11). In another report the same reaction was discovered to be catalyzed by applying copper nanoparticle (CuNP) as a cathode for elelctrohydrogenation of 12 [39]. The asymmetry was

• asymmetric electrocarboxylation of 4-methylpropiophenone. Enantioselective hydrogenation of methyl benzoylformate using an alkaloid entrapped silver cathode. Alkaloid-induced enantioselective hydrogenation using a Cu nanoparticle cathode. Alkaloid-induced enantioselective hydrogenation of aromatic ketones

A photochemical determination of luminescence efficiency of upconverting nanoparticles

• Baptiste Amouroux,
• Clément Roux,
• Jean-Claude Micheau,
• Fabienne Gauffre and
• Christophe Coudret

Beilstein J. Org. Chem. 2019, 15, 2671–2677, doi:10.3762/bjoc.15.260

• efficiency of these green-emitting “nanolamps”. The agreement of the collected data with the previous published results validates this approach. Keywords: actinometry; diarylethene; lanthanide; photochemistry; upconverting nanoparticle; Introduction The photophysical property of converting low-energy light

• knowing NYb the number of ytterbium per nanoparticle: NYb and NEr (NEr: number of erbium atom per particles) can be derived from the number of RE atoms per NP, itself computed from TEM and XRD measurements taking into account the nanoparticles size (volume ≈ 5400 ± 1000 nm3), unit cell volume (107.6 Å3

• energy of a 540 nm photon, to the emitting power of a single nanoparticle and the number of emitted photons per erbium atom J0/nEr in photon s−1. All of these numbers are gathered in Table 2, more detailed calculations are provided in Supporting Information File 1. The as-determined quantum yield is in

Reversible switching of arylazopyrazole within a metal–organic cage

• Anton I. Hanopolskyi,
• Soumen De,
• Michał J. Białek,
• Yael Diskin-Posner,
• Liat Avram,
• Moran Feller and
• Rafal Klajn

Beilstein J. Org. Chem. 2019, 15, 2398–2407, doi:10.3762/bjoc.15.232

• found to be stabilized in their zwitterionic form when confined to iron oxide nanoparticles [24]. Similarly, the ability of anthracenes to photodimerize greatly depends on the curvature of their “host” nanoparticle [25]. Despite these advances, we are still far from achieving the ease and elegance, with

Aggregation-induced emission effect on turn-off fluorescent switching of a photochromic diarylethene

• Luna Kono,
• Yuma Nakagawa,
• Ayako Fujimoto,
• Ryo Nishimura,
• Yohei Hattori,
• Toshiki Mutai,
• Nobuhiro Yasuda,
• Kenichi Koizumi,
• Satoshi Yokojima,
• Shinichiro Nakamura and
• Kingo Uchida

Beilstein J. Org. Chem. 2019, 15, 2204–2212, doi:10.3762/bjoc.15.217

• the crystalline state. The mechanism of the fast quenching is expected to be related to the amplification of photo-switching of a photochromic organic nanoparticle system as well as the crystalline system reported by Fukaminato and co-workers [29][30]. A detailed study of the amplification will be

Design, synthesis and biological evaluation of immunostimulating mannosylated desmuramyl peptides

• Rosana Ribić,
• Ranko Stojković,
• Lidija Milković,
• Mariastefania Antica,
• Marko Cigler and
• Srđanka Tomić

Beilstein J. Org. Chem. 2019, 15, 1805–1814, doi:10.3762/bjoc.15.174

• , a powerful supramolecular nanoparticle carrier for targeted drug delivery [38]. Previous research suggested a design of mannosylated desmuramyl peptides with adamantane at the C-terminus in order to facilitate the incorporation into the hydrophobic layer of the cavity because of the minor steric

Reversible end-to-end assembly of selectively functionalized gold nanorods by light-responsive arylazopyrazole–cyclodextrin interaction

• Maximilian Niehues,
• Patricia Tegeder and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2019, 15, 1407–1415, doi:10.3762/bjoc.15.140

• nanoparticle systems [18][19][20][21][22][23][24]. The host–guest interaction can be responsive to external stimuli such as redox, pH or light, with the latter being the most desirable for assembling nanoparticles by virtue of its noninvasive nature [25]. Prominent light-responsive guest molecules are

• nanoparticle systems [46]. This interpretation is also supported by TEM images (Figure 4a, see below) indicating significant interparticle repulsion and no aggregation-induced absorption maxima broadening. For further experiments the [tCD+tTEG]AuNR stock solution was diluted with ddH2O. For the photoresponsive

• uncontrolled aggregation would result in an additional shift of the TSPR band [15]. In the course of repeated photoswitching experiments, the spectra show a small but significant decrease of the overall nanoparticle absorbance which is most likely due to sedimentation of irreversible aggregates or size

Fabrication, characterization and adsorption properties of cucurbit[7]uril-functionalized polycaprolactone electrospun nanofibrous membranes

• Changzhong Chen,
• Fengbo Liu,
• Xiongzhi Zhang,
• Zhiyong Zhao and
• Simin Liu

Beilstein J. Org. Chem. 2019, 15, 992–999, doi:10.3762/bjoc.15.97

• isotherm model. Keywords: adsorption; cucurbit[7]uril; electrospinning; macrocycles; methylene blue; nanofiber; Introduction Electrospinning is recognized as the most simple and versatile method to fabricate multifunctional nanofibers from the solution or melt of polymers, polymer/nanoparticle mixtures

Application of olefin metathesis in the synthesis of functionalized polyhedral oligomeric silsesquioxanes (POSS) and POSS-containing polymeric materials

• Patrycja Żak and
• Cezary Pietraszuk

Beilstein J. Org. Chem. 2019, 15, 310–332, doi:10.3762/bjoc.15.28

• copolymers assemble into small, randomly oriented lamellae with lateral dimensions of approximately 50 nm and a thickness of ca 3–5 nm that corresponds to twice the diameter of a POSS nanoparticle. With increasing POSS concentration, the nanostructures extend to longer continuous lamellae having lateral

On the design principles of peptide–drug conjugates for targeted drug delivery to the malignant tumor site

• Eirinaios I. Vrettos,
• Gábor Mező and
• Andreas G. Tzakos

Beilstein J. Org. Chem. 2018, 14, 930–954, doi:10.3762/bjoc.14.80

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

• similar morphology [56][112]. The metal nanoparticle core is covered by polymeric brushes, the length and the grafting are important factors which can affect the reaction, as discussed in the following paragraph, and the easy manufacturing of metal nanoparticles makes the preparation of these core-brushes

Mannich base-connected syntheses mediated by ortho-quinone methides

• Petra Barta,
• Ferenc Fülöp and
• István Szatmári

Beilstein J. Org. Chem. 2018, 14, 560–575, doi:10.3762/bjoc.14.43

• acid nanoparticles (ASA NPs) proved to be efficient under neat conditions for the synthesis of 1-amidoalkyl-2-naphthols [19]. Zali et al. carried out this synthesis applying nano-sulfated zirconia [20], Borhade et al. used PbS nanoparticles [21], while Safari et al. applied magnetic-nanoparticle

An alternative to hydrogenation processes. Electrocatalytic hydrogenation of benzophenone

• Cristina Mozo Mulero,
• Alfonso Sáez,
• Jesús Iniesta and
• Vicente Montiel

Beilstein J. Org. Chem. 2018, 14, 537–546, doi:10.3762/bjoc.14.40

• bottlenecks or blockage of network across the electrocatalytic layer, or likely some of these Pd nanoparticles could be covered up each other so those ones would be hidden. Once Pd nanoparticle-based cathodes were manufactured and characterised, electrolytic hydrogenation of benzophenone in a cathodic process

Stimuli-responsive oligonucleotides in prodrug-based approaches for gene silencing

• Françoise Debart,
• Christelle Dupouy and
• Jean-Jacques Vasseur

Beilstein J. Org. Chem. 2018, 14, 436–469, doi:10.3762/bjoc.14.32

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

• Ranjana Aggarwal and
• Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

Recent applications of click chemistry for the functionalization of gold nanoparticles and their conversion to glyco-gold nanoparticles

• Vivek Poonthiyil,
• Thisbe K. Lindhorst,
• Vladimir B. Golovko and
• Antony J. Fairbanks

Beilstein J. Org. Chem. 2018, 14, 11–24, doi:10.3762/bjoc.14.2

• combination of a gold nanoparticle core and an outer-shell comprising multivalent presentation of carbohydrates. The combination of the distinctive physicochemical properties of the gold core and the biological function/activity of the carbohydrates makes glyco-gold nanoparticles a valuable tool in

New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions

• Daily Rodríguez-Padrón,
• Alina M. Balu,
• Antonio A. Romero and
• Rafael Luque

Beilstein J. Org. Chem. 2017, 13, 1982–1993, doi:10.3762/bjoc.13.194

• been an attractive option to imitate based on a fundamental and rational understanding [28][32]. In that sense, polysaccharides extracted from fungal organisms can be used both as nanoparticle carriers and sacrificial templates due to their highly functionalized structure. Although such carbohydrates

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• materials like stainless steel, tungsten carbide, zirconia, agate, etc. [24]. In the past decade, mechanochemical reactions were developed under the areas of chemistry like supramolecular chemistry [25][26], organic synthesis [27][28], nanoparticle synthesis, etc. [29][30]. The historical development of

Ni nanoparticles on RGO as reusable heterogeneous catalyst: effect of Ni particle size and intermediate composite structures in C–S cross-coupling reaction

• Debasish Sengupta,
• Koushik Bhowmik,
• Goutam De and
• Basudeb Basu

Beilstein J. Org. Chem. 2017, 13, 1796–1806, doi:10.3762/bjoc.13.174

• catalytic process has been established for the first time, and found to be best in the C–S cross-coupling reaction for Ni(0) and Ni(II) NPs of the average sizes 11–12 nm and 4 nm, respectively. Keywords: C–S cross-coupling; heterogeneous catalyst; Ni nanoparticle; reduced graphene oxide; thioether

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

• make this protocol a great option for stilbene syntheses by Mizoroki–Heck reaction. Keywords: aqueous reaction medium; MAOS; Mizoroki–Heck reaction; Pd nanoparticle; sustainable organic synthesis; Introduction Palladium-catalyzed reactions have emerged as an important tool for organic synthesis

• transmission electron microscope (TEM) images and the total content of Pd in the colloidal suspensions was determined by atomic absorption. Synthesis of Pd nanoparticle suspensions under MW irradiation In a 10 mL MW tube equipped with a magnetic stirring bar, 0.125 mL of H2PdCl4 2 mM (2.5 × 10−4 mmol), 16 g/L

Block copolymers from ionic liquids for the preparation of thin carbonaceous shells

• Sadaf Hanif,
• Bernd Oschmann,
• Dmitri Spetter,
• Muhammad Nawaz Tahir,
• Wolfgang Tremel and
• Rudolf Zentel

Beilstein J. Org. Chem. 2017, 13, 1693–1701, doi:10.3762/bjoc.13.163

• anchor group could bind to inorganic nanoparticle surfaces, where a second polymer block could be converted into a conductive carbon shell, improving the properties of nanoparticles like TiO2 or ZnO with respect to the reversible storage of lithium or sodium ions [22][23][24][25]. Using a block copolymer

• with an anchor group to bind on the nanoparticle surface allows the formation of a homogenous and thin coating. So far, polyacrylonitrile has been used as a carbonizable block, but polymeric ionic liquids are attractive as well. An approach to coat nanoparticles with either (i) a thin film of PILs or

• route to carbon-coated TiO2 nanoparticles using block copolymers is displayed in Figure 1a. The block copolymers containing an anchoring block and a carbonizable block should function – at first – as a ligand for the nanoparticle synthesis to produce polymer functionalized nanoparticles. The heat

Synthesis and metal binding properties of N-alkylcarboxyspiropyrans

• Alexis Perry and
• Christina J. Kousseff

Beilstein J. Org. Chem. 2017, 13, 1542–1550, doi:10.3762/bjoc.13.154

• nanoparticles has enabled photomodulation of nanoparticle fluorescence [10][11]. Similarly, tagged N-alkylcarboxyspiropyrans have provided the basis for photoactive biopolymers, e.g., polypeptides with photocontrolled folding [12], light-activated enzymes [13], light-enhanced affinity chromatography using