Cyclodextrins as building blocks for new materials

• Miriana Kfoury and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2023, 19, 889–891, doi:10.3762/bjoc.19.66

• use of CDs and further stimulate their market. The exploration of the potential of inclusion complexation is not limited to the biomedical field. CDs are renewable and biodegradable materials that enable green and environmental biotechnologies for all applications [11]. The ability of CDs to act as

Light-responsive rotaxane-based materials: inducing motion in the solid state

• Adrian Saura-Sanmartin

Beilstein J. Org. Chem. 2023, 19, 873–880, doi:10.3762/bjoc.19.64

• direction, one potential strategy is the approach followed by Feringa and co-workers [72], in which palladium-porphyrin photosensitizer-based struts were employed within a metal-organic material, allowing the use of green light as irradiation source because of the effective energy transfer between these

Synthesis of substituted 8H-benzo[h]pyrano[2,3-f]quinazolin-8-ones via photochemical 6π-electrocyclization of pyrimidines containing an allomaltol fragment

• Constantine V. Milyutin,
• Andrey N. Komogortsev,
• Boris V. Lichitsky,
• Mikhail E. Minyaev and
• Valeriya G. Melekhina

Beilstein J. Org. Chem. 2023, 19, 778–788, doi:10.3762/bjoc.19.58

• systems which are unavailable by other methods. Wherein, usually UV-promoted reactions are environmentally friendly due to the absence of toxic reagents, which is especially perspective in context of green chemistry [9][10]. Thus, studies of the photochemical behavior of organic compounds play an

Sulfate radical anion-induced benzylic oxidation of N-(arylsulfonyl)benzylamines to N-arylsulfonylimines

• Joydev K. Laha,
• Pankaj Gupta and
• Amitava Hazra

Beilstein J. Org. Chem. 2023, 19, 771–777, doi:10.3762/bjoc.19.57

• with ortho-substituted anilines is also reported. The key features of the protocol include the use of a green oxidant, a short reaction time (30 min), chromatography-free isolation, scalability, and economical, delivering N-arylsulfonylimines in excellent yields of up to 96%. While the oxidation of N

• -substituted anilines. The key features including the use of a green oxidant, a short reaction time, chromatography-free isolation, and scalability mark a distinction from the contemporary methods. Although we propose a dual role for SO4·− involving both hydrogen atom abstraction (HAT) and single electron

Honeycomb reactor: a promising device for streamlining aerobic oxidation under continuous-flow conditions

• Masahiro Hosoya,
• Yusuke Saito and
• Yousuke Horiuchi

Beilstein J. Org. Chem. 2023, 19, 752–763, doi:10.3762/bjoc.19.55

• -oxyl (TEMPO) oxidation [8]. TEMPO oxidation, in particular, has been successfully applied on a manufacturing scale as a low-cost and green oxidation method [9]. However, these oxidation processes generally require stoichiometric oxidants, and reduced byproducts must be purged in a purification step

Palladium-catalyzed enantioselective three-component synthesis of α-arylglycine derivatives from glyoxylic acid, sulfonamides and aryltrifluoroborates

• Bastian Jakob,
• Nico Schneider,
• Luca Gengenbach and
• Georg Manolikakes

Beilstein J. Org. Chem. 2023, 19, 719–726, doi:10.3762/bjoc.19.52

• α-arylglycine motifs (highlighted in green and blue). The Petasis reaction – fundamental reactivities and recent developments. Observations from previous studies and mechanistic rationale. Initial experiments. Reaction scope – aryltrifluoroborates (yields and enantiomeric ratios in parentheses refer

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• (highlighted in green). In comparison to linearly conjugated materials, oligomeric and polymeric compounds with a fully cross-conjugated carbon backbone are relatively unexplored [17][18][19][20]. Molecules of this type serve not only as objects of fundamental research into the phenomena of cross-conjugation

• nitro group. There are two types of independent non-equivalent dications, marked in blue and green, and two types of BF4− anions, marked in red and yellow, in the crystal structure of salt 11c (Figure S68 in Supporting Information File 1). Monomer fragments in both are identical (Table 2, Figure 5). The

• directions of electron density transfer are possible (Figure 7): between two DMAN fragments through the butadiyne linker (highlighted in green) and between the DMAN and aryl rings through the acetylene bridge (highlighted in blue). Obviously, the “butadiyne path” includes a longer conjugation chain

pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene

• Nan Yang,
• Yi-Yan Zhu,
• Wei-Xiu Lin,
• Yi-Long Lu and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45

• powders of CS-TPE exhibit a pale-yellow appearance under normal daylight conditions and emit intense green-blue light when exposed to UV irradiation (365 nm). This phenomenon differs greatly from the fluorescence properties of conventional ACQ fluorophores, which are typically nonfluorescent under UV

C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

• Grédy Kiala Kinkutu,
• Catherine Louis,
• Myriam Roy,
• Juliette Blanchard and
• Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

• formation of the imine directing group and the C3-functionalization with some vinylsilanes and norbonene. Keywords: biomass; C–H activation; flow; furfural; homogeneous catalysis; Introduction The conversion of biomass derivatives into value-added products is one of the key branches of green chemistry and

Direct C2–H alkylation of indoles driven by the photochemical activity of halogen-bonded complexes

• Martina Mamone,
• Giuseppe Gentile,
• Jacopo Dosso,
• Maurizio Prato and
• Giacomo Filippini

Beilstein J. Org. Chem. 2023, 19, 575–581, doi:10.3762/bjoc.19.42

• both UV–vis and nuclear magnetic resonance (NMR) spectroscopy [29]. In particular, the optical absorption spectra of substrate 2a (green dotted line), DABCO (red dotted line), and the solution containing both 2a and DABCO (blue line) were recorded in acetonitrile (Figure 2). Specifically, it was

A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes

• Alena V. Dmitrieva,
• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41

• are presented in different colors: the hydrogen bonding are labeled in blue color of the reduced density gradient isosurface; green color corresponds to the dispersion interactions (van der Waals interactions, the π-stacking); red color represents steric clashes. The interplay of these through-space

• protons. Low-gradient isosurfaces with low densities (blue color of the isosurface corresponds to the hydrogen bonding; the dispersion interactions (van der Waals interactions, the π-stacking) are marked in green color; red color indicates steric clashes) obtained for the ʟ- (left image) and ᴅ-alanine

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

• catalysts, iron is bringing a renaissance to the idea of sustainable, green catalysis. In 2011, Ito et al. reported a diastereoselective Fe-catalyzed carbozincation of heterobicyclic alkenes 1 with diphenylzinc (74a) (Scheme 13) [47]. Using an ortho-phenylene diphosphine ligand L3, the authors were able to

Computational studies of Brønsted acid-catalyzed transannular cycloadditions of cycloalkenone hydrazones

• Manuel Pedrón,
• Jana Sendra,
• Irene Ginés,
• Tomás Tejero,
• Jose L. Vicario and
• Pedro Merino

Beilstein J. Org. Chem. 2023, 19, 477–486, doi:10.3762/bjoc.19.37

• cyclohexanes. The resulting system is given in square brackets. In parentheses the integration over the volumes of −λ2·ρ2 representing the total integration data corresponding to the weak noncovalent van der Waals interactions (represented in green). Higher forces like H-bonds are indicated as blue discs. In

Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview

• Louis Monsigny,
• Floriane Doche and
• Tatiana Besset

Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35

• direct dehydrogenative 2,2,2-trifluoroethoxylation of (hetero)arenes, often using 2,2,2-trifluoroethanol as a readily available, inexpensive, and green fluorination source [159][160], is still underexplored. In 2004, Sanford and co-workers reported the dehydrogenative 2,2,2-trifluoroethoxylation of benzo

Mechanochemical solid state synthesis of copper(I)/NHC complexes with K₃PO₄

• Ina Remy-Speckmann,
• Birte M. Zimmermann,
• Mahadeb Gorai,
• Martin Lerch and
• Johannes F. Teichert

Beilstein J. Org. Chem. 2023, 19, 440–447, doi:10.3762/bjoc.19.34

• been shown to be active in a variety of reduction/hydrogenation transformations employing dihydrogen as terminal reducing agent. Keywords: ball mill; bifunctional catalysis; catalytic hydrogenations; copper; mechanochemical synthesis; N-heterocyclic carbenes; Introduction Prominent goals of green

• challenge for syntheses is the development of green and environmentally friendly routes to access value-added products. One important way to more economical syntheses is the concept of catalysis to avoid stoichiometric amounts of reactants and to design reactions more atom efficient [1][2][3]. However, the

• of green chemistry. Syntheses via mechanochemical methods offer elegant and atom-economic alternatives to liquid state synthesis approaches [33][34][35][36][37][38][39][40][41][42][43]. In accordance with the in situ transmetallation route in liquid state synthesis, a one-pot two-step procedure in a

Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis

• Nicoleta G. Hădărugă,
• Gabriela Popescu,
• Dina Gligor (Pane),
• Cristina L. Mitroi,
• Sorin M. Stanciu and
• Daniel Ioan Hădărugă

Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30

• -cyclodextrin/Corylus avellana oil/hesperidin ternary complex at a 1:1:1 molar ratio (blue), β-cyclodextrin hydrate (red), C. avellana oil (pink), and hesperidin (green). Superposition of the FTIR spectra for the β-cyclodextrin/Corylus avellana oil/hesperidin ternary complex at a 3:1:1 molar ratio (blue), β

• -cyclodextrin hydrate (red), C. avellana oil (pink), and hesperidin (green). PC2 versus PC1 scores plot from the FTIR–PCA analysis of the flavonoid glycoside and flavonolignan antioxidants (codes: “H” – hesperidin, “N” – naringin, “R” – rutin and “S” – silymarin); only wavenumbers of the FTIR bands were used as

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• excellent yields using Zn(OAc)2 in a CHCl3/MeOH mixture. Their UV–vis titration study revealed that these host systems exhibit strong anion-binding affinities. Furthermore, with the help of kinetic studies, the absorption efficiency of malachite green dye was investigated by using free-base porphyrins 171a

Synthesis, α-mannosidase inhibition studies and molecular modeling of 1,4-imino-ᴅ-lyxitols and their C-5-altered N-arylalkyl derivatives

• Martin Kalník,
• Sergej Šesták,
• Juraj Kóňa,
• Maroš Bella and
• Monika Poláková

Beilstein J. Org. Chem. 2023, 19, 282–293, doi:10.3762/bjoc.19.24

• synthetic Golgi α-mannosidase II inhibitors with their activity profile toward the Golgi-type α-mannosidases. Superposition of the inhibitor 29 (green), docked into dGMII, with X-ray complexes of swainsonine (pink) with dGMII (PDB ID: 3BLB) [39]. The hydroxyethyl moiety at C-5 of 29 is placed at the same

• /MM optimized complexes 28:dGMII (top) and 31:dGMII (bottom) [22]. N-2-naphthylmethyl group (grey) and (R)-1-hydroxyethyl group (green) of 28 and the hydroxymethyl group (green) of 31 are visualized by van der Waals spheres to highlight the unfavorable interaction (marked with a black arrow) between

Investigation of cationic ring-opening polymerization of 2-oxazolines in the “green” solvent dihydrolevoglucosenone

• Solomiia Borova and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2023, 19, 217–230, doi:10.3762/bjoc.19.21

• of 2-ethyl-2-oxazoline and 2-butyl-2-oxazoline using a variety of initiators in the recently commercialized "green" solvent dihydrolevoglucosenone (DLG). Detailed 1H NMR spectroscopic analysis was performed to understand the influence of the temperature and concentration on the polymerization process

• ]. Therefore, choosing environmentally benign solvents becomes ever more relevant [27]. Accordingly, some research groups have been also looking for "green" and safer solvents suitable for CROP of 2-oxazolines. "Green" solvents are considered environmentally friendly, less hazardous solvents that make a

• bio-based solvent obtained from cellulose [36][37], commercially known as CyreneTM, and has been introduced as a new "green" solvent marketed specifically as an alternative to solvents such as DMF or NMP, which are particularly interesting for CROP of POx. It is reported that DLG is safe to handle

Total synthesis of insect sex pheromones: recent improvements based on iron-mediated cross-coupling chemistry

• Eric Gayon,
• Guillaume Lefèvre,
• Olivier Guerret,
• Adrien Tintar and
• Pablo Chourreu

Beilstein J. Org. Chem. 2023, 19, 158–166, doi:10.3762/bjoc.19.15

• industrial kilogram scales, leading to green, efficient and economically viable processes. Mechanistic considerations The improvements of the initial cross-coupling conditions developed by Kochi (Scheme 2a) discussed in this report have high potent synthetic applications since they do not require well

Insight into oral amphiphilic cyclodextrin nanoparticles for colorectal cancer: comprehensive mathematical model of drug release kinetic studies and antitumoral efficacy in 3D spheroid colon tumors

• Sedat Ünal,
• Gamze Varan,
• Juan M. Benito,
• Yeşim Aktaş and
• Erem Bilensoy

Beilstein J. Org. Chem. 2023, 19, 139–157, doi:10.3762/bjoc.19.14

• . As seen in Figure 6, cells were double-stained with calcein AM and ethidium homodimer-1 (EthD-1). The control group consisted of cells incubated only with the medium. Living cells were stained green with the membrane dye calcein AM, while dead cells were stained red with the nuclear dye EthD-1. Both

Organophosphorus chemistry: from model to application

• György Keglevich

Beilstein J. Org. Chem. 2023, 19, 89–90, doi:10.3762/bjoc.19.8

• newly prepared thiophosphorus acids were not efficient in the asymmetric transfer hydrogenation of 2-phenylquinoline. However, they may find application in other model reactions. These days, stereoselective syntheses incorporating “green" chemical considerations are of utmost importance in medicinal

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

• polysaccharides. Xanthan gum, locust bean gum or chitosan can be crosslinked using citric acid in the presence of β-cyclodextrin to produce insoluble matrices. In this work, polymeric foams based on those polysaccharides and saponin have been prepared using a green synthesis method to increase the porosity of the

• ; green synthesis; locust bean gum; saponin; sorption; xanthan gum; Introduction Saponins are a family of natural molecules consisting of a hydrophobic aglycone backbone grafted with hydrophilic sugar molecules, allowing the plant to be protected from illnesses [1] and from herbivores endangerment [2

• polysaccharide networks using cyclodextrin to prepare green adsorbents [37]. The use of saponins added into the reactive mixture in order to produce a foam allows us to prepare porous materials, in order to enhance their sorption capabilities when a low amount of the sorbate is present in the solution. The

Combining the best of both worlds: radical-based divergent total synthesis

• Kyriaki Gennaiou,
• Antonios Kelesidis,
• Maria Kourgiantaki and
• Alexandros L. Zografos

Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1

• complex natural structures and the practicality of delivering highly diverged lead compounds for biological screening, is the constant aim of the organic chemistry community. Delivering natural lead compounds became easier during the last two decades, with the evolution of green chemistry and the concepts

• of divergent synthesis, common synthetic scaffolds, which are regarded as the points of diversity of the synthetic plan, lie at the heart of retrosynthetic design. Radical disconnections on common scaffolds, in accordance to the trends of green chemistry [11] and the concepts of atom economy [12] and

Inline purification in continuous flow synthesis – opportunities and challenges

• Jorge García-Lacuna and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

• ]. Moreover, a high process mass intensity, good space time yield and high product purity were obtained, proving these inline separation techniques can be used as a green and effective purification tool. Previously, Jamison and co-workers performed a total synthesis of atropine in flow using a similar setup

• heterogeneous fashion. This oftentimes leads to improved green credentials, safety, and sometimes efficiency, especially when it is applied to the downstream process. Commercially available resins, activated charcoal, polymer-supported species that trap spent reagents or side-products as well as related

• can be observed in the flow syntheses of rufinamide [121] and diphenhydramine hydrochloride [122]. These protocols are notable for being green, atom efficient, and inexpensive due to the reduction in solvent use. Another similar scenario that is not fully explored relates to flow processes at elevated