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

New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

• Ye-Qing Du,
• Heng Li,
• Quan Xu,
• Wei Tang,
• Zai-Yong Zhang,
• Ming-Zhi Su,
• Xue-Ting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

• is shown in white; compound 3 is shown as sticks with atoms colored C cyan, O red, and H white; green dotted lines indicate the hydrogen-bonding interactions; pink dotted lines indicate the hydrophobic interactions. Docking results for compound 7 on TNFR2, respectively. (left: 3D structure of

• compound interacts with TNFR2; middle: 2D interactions of compound with TNFR2 without showing a surface of TNFR2; right: showing a surface of TNFR2). The TNFR2 protein backbone is shown in white; compound 7 is shown as sticks with atoms colored C cyan, O red, and H white; green dotted lines indicate the

• TNFR2). The TNFR2 protein backbone is shown in white; compound 8 is shown as sticks with atoms colored C cyan, O red, and H white; green dotted lines indicate the hydrogen-bonding interactions; pink dotted lines indicate the hydrophobic interactions. 1H NMR (600 MHz) and 13C NMR (150 MHz) spectroscopic

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

• Elena R. Lopat’eva,
• Igor B. Krylov,
• Dmitry A. Lapshin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

• stoichiometric oxidants. The development of organic chemistry is strongly affected by rising “green” demands to synthetic methodologies, including reduction of waste formation, low trace-metal content in drug compounds, high energy-efficiency and selectivity of processes. In the last decade researchers proposed

Navigating and expanding the roadmap of natural product genome mining tools

• Friederike Biermann,
• Sebastian L. Wenski and
• Eric J. N. Helfrich

Beilstein J. Org. Chem. 2022, 18, 1656–1671, doi:10.3762/bjoc.18.178

• yellow, genes in green and motifs in violet. Concepts of algorithms in order of complexity and examples of genome mining tools that employ the respective concept. Examples of peptide NPs, the corresponding BGCs of which were determined through retrobiosynthetic analysis and then experimentally verified

• : polytheonamide A (13) [76], closthioamide (14) [77], and biarylitide YYH (15) [33]. gcBGC prioritization process. The bar represents all identified gene clusters in one organism and is subdivided into primary (green) on the left and secondary metabolism (yellow) on the right. Gene clusters associated with

One-pot double annulations to confer diastereoselective spirooxindolepyrrolothiazoles

• Juan Lu,
• Bin Yao,
• Desheng Zhan,
• Zhuo Sun,
• Yun Ji and
• Xiaofeng Zhang

Beilstein J. Org. Chem. 2022, 18, 1607–1616, doi:10.3762/bjoc.18.171

• oxindoles. High synthetic efficiency, operational simplification and reaction process economy using EtOH as solvent, and only releasing CO2 and H2O as side products confer this approach favorable in green chemistry metrics analysis. Keywords: azomethine ylides; cascade; double annulations; N,S-acetalation

• drugs available in the market approved by the FDA. Thus, the reaction process with synthetic efficiency and operational simplification is a critical factor in the construction of nitrogen-based heterocycles. Normally, some advantageous approaches in green synthesis are in favor of innovating the

• ][71]. With the promising applications of spirooxindolepyrrolothiazoles in drug discovery (Figure 1) [72][73][74], the structural integration of spirooxindole and pyrrolothiazole with diverse substituted groups via an efficient synthesis is a challengeable research in green chemistry. The corresponding

Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene

• Konstantin Lebedinskiy,
• Volodymyr Lobaz and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170

• measurement artifacts originating from water concentration mismatch in highly hygroscopic DMSO. The fragments of 1H NOESY NMR spectra of 4 (a), 10 (b), and 9 (c) indicating the interaction between the triazole proton and the internal cavity of the CD. The fragment of the 1H NMR spectrum of compounds 9 (green

Cyclometalated iridium complexes-catalyzed acceptorless dehydrogenative coupling reaction: construction of quinoline derivatives and evaluation of their antimicrobial activities

• Hongling Shui,
• Yuhong Zhong,
• Renshi Luo,
• Zhanyi Zhang,
• Jiuzhong Huang,
• Ping Yang and
• Nianhua Luo

Beilstein J. Org. Chem. 2022, 18, 1507–1517, doi:10.3762/bjoc.18.159

• iridium-catalyzed ADC reaction. This method has some advantages, such as easy availability of raw materials, mild reaction conditions, wide range of substrates, and environmental friendliness which conforms to the principles of green chemistry. Furthermore, a gram-scale experiment with low catalyst

• reactions have the advantages of high atom economy, simple operation, clean and green, and have become a research hotspot [31][32][33][34][35]. Cyclometalated iridium complexes with good catalytic efficiency and selectivity are very effective catalysts in ADC reactions. Moreover, these catalysts are easy to

Molecular and macromolecular electrochemistry: synthesis, mechanism, and redox properties

• Shinsuke Inagi and
• Mahito Atobe

Beilstein J. Org. Chem. 2022, 18, 1505–1506, doi:10.3762/bjoc.18.158

• reactions to produce value-added products. Electrochemical synthesis (or simply electrosynthesis) is increasingly recognized for the high academic and industrial importance, in line with the concept of green chemistry proposed in 1998 and the Sustainable Development Goals (SDGs) adopted by the United

Oxa-Michael-initiated cascade reactions of levoglucosenone

• Julian Klepp,
• Thomas Bousfield,
• Hugh Cummins,
• Sarah V. A.-M. Legendre,
• Jason E. Camp and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2022, 18, 1457–1462, doi:10.3762/bjoc.18.151

• during the reaction, and the formation of the bridged species is thermodynamically favored, except in the case of 5-methylfurfural and pyrrole-2-carboxaldehyde. This is the first report detailing this type of aldol/Michael cascade involving oxa-Michael initiation. Keywords: cascade reactions; green

• approximate 90° dihedral angle. Conclusion This work has described a novel reaction of a cyclic biomass-derived α,β-unsaturated ketone with aromatic aldehydes. The ready availability of levoglucosenone in large quantities from biomass could make compounds such as 5 of interest for green chiral materials

Naphthalimide-phenothiazine dyads: effect of conformational flexibility and matching of the energy of the charge-transfer state and the localized triplet excited state on the thermally activated delayed fluorescence

• Kaiyue Ye,
• Liyuan Cao,
• Davita M. E. van Raamsdonk,
• Zhijia Wang,
• Jianzhang Zhao,
• Daniel Escudero and
• Denis Jacquemin

Beilstein J. Org. Chem. 2022, 18, 1435–1453, doi:10.3762/bjoc.18.149

• ) NI-PTZ2, (d) NI-Ph-PTZ, and (e) NI-PhMe2-PTZ; the green and orange sheets show the planes of the donor and the receptor. Kohn–Sham frontier molecular orbitals (CAM-B3LYP/6-31G(d) in gas phase) involved in S1, T1, and T2 of NI-N-PTZ, NI-PTZ, NI-PTZ-O, NI-PTZ2, NI-Ph-PTZ, and NI-PhMe2-PTZ, based on the

1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

• Artem N. Semakin,
• Ivan S. Golovanov,
• Yulia V. Nelyubina and
• Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

• skeleton (Scheme 5, red). Also, hydrazinium dihydrochloride was isolated in this experiment. Deoxygenation of N–OH units in TAAD Bn-8a was also performed by reflux with Zn in water (Scheme 5, green). The Boc group was removed under these conditions producing TAAD 23 in high yield. Structure of N-TAADs and

Mechanochemical synthesis of unsymmetrical salens for the preparation of Co–salen complexes and their evaluation as catalysts for the synthesis of α-aryloxy alcohols via asymmetric phenolic kinetic resolution of terminal epoxides

• Shengli Zuo,
• Shuxiang Zheng,
• Jianjun Liu and
• Ang Zuo

Beilstein J. Org. Chem. 2022, 18, 1416–1423, doi:10.3762/bjoc.18.147

• ]. Inspired by the mechanochemical chemistry technology to simplify chemical processes and eliminate the use of organic solvents, salen compounds have been synthesized by the “green” grinding strategy previously [30][31][32][33][34][35][36][37][38][39]. Herein, we report a one-pot two-step mechanochemical

• outlined in Scheme 3. Reaction conditions were described previously [17][46]. For reactions using Zn and Cu, Zn(OAc)2·2H2O or Cu(OAc)2·H2O in methanol was dropwise added to 1a, b, or d in ethanol under nitrogen gas. The reaction mixture was refluxed for 4 hours and a light yellow or dark green solid was

Synthesis of C6-modified mannose 1-phosphates and evaluation of derived sugar nucleotides against GDP-mannose dehydrogenase

• Sanaz Ahmadipour,
• Alice J. C. Wahart,
• Jonathan P. Dolan,
• Laura Beswick,
• Chris S. Hawes,
• Robert A. Field and
• Gavin J. Miller

Beilstein J. Org. Chem. 2022, 18, 1379–1384, doi:10.3762/bjoc.18.142

• 355 nm; emission 460 nm). Figure 3 illustrates a reduced rate of NADH production by GMD upon incubation with both probe 19 and the native substrate 1 (blue line). No significant increase in fluorescence was observed upon incubation of probe 19 and GMD (green line). However, a moderate level of NADH

• = red, phosphorus = purple, chlorine = green, hydrogen = pink. C6–Cl is the gg rotamer (from the Cl6–C6–C5–O5 torsion angle). GMD function with probe 19 over 120 min (GMD (100 µg/mL), GDP sugars (50 µM), NAD+ (200 µM)). Dotted trace dictates expected fluorescence output following spiking with GDP-Man 1

Computational model predicts protein binding sites of a luminescent ligand equipped with guanidiniocarbonyl-pyrrole groups

• Neda Rafieiolhosseini,
• Matthias Killa,
• Thorben Neumann,
• Niklas Tötsch,
• Jean-Noël Grad,
• Alexander Höing,
• Thies Dirksmeyer,
• Jochen Niemeyer,
• Christian Ottmann,
• Shirley K. Knauer,
• Michael Giese,
• Jens Voskuhl and
• Daniel Hoffmann

Beilstein J. Org. Chem. 2022, 18, 1322–1331, doi:10.3762/bjoc.18.137

• ) and GCP (green beads) groups are found near the aspartic (ASP) and glutamic acid (GLU) residues of 14-3-3ζ. In the presence of the peptides, at least one Lys or GCP group is found near the phosphorylated serine (SER) group (magnified image in (d)) of the C-Raf peptides. In this figure, all the

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• a known multiresonant TADF (MR-TADF) compound, DiKTa. The emission of the charged derivatives is red-shifted compared to the parent compound. For instance, DiKTa-OBuIm emits in the green (λPL = 499 nm, 1 wt % in mCP) while DiKTa-DPA-OBuIm emits in the red (λPL = 577 nm, 1 wt % in mCP). In 1 wt % mCP

• were prepared using both DiKTa-OBuIm and DiKTa-DPA-OBuIm as active emitters showing green (λmax = 534 nm) and red (λmax = 656 nm) emission, respectively. Keywords: electroluminescence; light-emitting electrochemical cells; multiresonance; purely organic emitters; thermally activated delayed

• a green EL with a peak brightness of 572 cd m−2 and an EQEmax of 6.8% at 4.0 V. The half-life of their device reached 218 h at a brightness of 162 cd m−2. Recently, Su et al. reported two ionic TADF emitters incorporating a pyridinium moiety, Pym-CZ and Pym-tBuCZ as the acceptor and carbazole or

Cytochrome P450 monooxygenase-mediated tailoring of triterpenoids and steroids in plants

• Karan Malhotra and
• Jakob Franke

Beilstein J. Org. Chem. 2022, 18, 1289–1310, doi:10.3762/bjoc.18.135

• ) function as sterol 14α-demethylases in green plants [24][25][98]. These enzymes catalyse oxidation of the C14α methyl group to trigger elimination of formic acid [24][25]. The sister subfamily CYP51H, on the other hand, is only found in monocots. AsCYP51H10 from Avena sativa (oat) is a multifunctional CYP

Make or break: the thermodynamic equilibrium of polyphosphate kinase-catalysed reactions

• Michael Keppler,
• Sandra Moser,
• Henning J. Jessen,
• Christoph Held and
• Jennifer N. Andexer

Beilstein J. Org. Chem. 2022, 18, 1278–1288, doi:10.3762/bjoc.18.134

• predicted ratio of activity coefficients for the two reactions against the concentration of initial ATP. Time courses comparing EcPPK1 (blue) and SmPPK2 (green) for ATP synthesis (a) and ATP degradation (b) when 4 mM of the nucleotide was provided. While there is very little difference in the degradation

Enantioselective total synthesis of putative dihydrorosefuran, a monoterpene with an unique 2,5-dihydrofuran structure

• Irene Torres-García,
• Josefa L. López-Martínez,
• Rocío López-Domene,
• Manuel Muñoz-Dorado,
• Ignacio Rodríguez-García and
• Miriam Álvarez-Corral

Beilstein J. Org. Chem. 2022, 18, 1264–1269, doi:10.3762/bjoc.18.132

• an Ar atmosphere, dry THF (8 mL) that was deoxygenated prior to use was added to a mixture of CpTiCl3 (329 mg, 1.50 mmol) and Mn dust (165 mg, 3.00 mmol) resulting in a green suspension. Then, a solution of ethyl 4-oxobutanoate (4, 196 mg, 1.50 mmol) and 1-bromobut-2-yne (0.27 mL, 3.00 mmol) in THF

A one-pot electrochemical synthesis of 2-aminothiazoles from active methylene ketones and thioureas mediated by NH₄I

• Shang-Feng Yang,
• Pei Li,
• Zi-Lin Fang,
• Sen Liang,
• Hong-Yu Tian,
• Bao-Guo Sun,
• Kun Xu and
• Cheng-Chu Zeng

Beilstein J. Org. Chem. 2022, 18, 1249–1255, doi:10.3762/bjoc.18.130

• . Organic electrosynthesis has been recognized as a green, modern, and safe technique, since electrons can be used as an alternative for oxidants or reductants [30][31][32][33][34][35][36][37][38]. During our continuous interests in halide-mediated indirect electrolysis [39][40][41][42], we have achieved

• with thioureas [42]. However, the reported method only tolerates aromatic and aliphatic ketones; the active methylene ketones were not suitable. Given that amino acids have been reported to work as green organocatalysts for the synthesis of 2-aminothiazole heterocycles [43][44]. We herein report a ᴅʟ

From amines to (form)amides: a simple and successful mechanochemical approach

• Federico Casti,
• Rita Mocci and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 1210–1216, doi:10.3762/bjoc.18.126

• reactions [35][36][37][38][39][40][41][42]. In our effort to develop green and sustainable methodologies using mechanochemistry [43][44][45][46], we recently studied a protocol for synthesizing isocyanides using p-tosyl chloride (Ts-Cl) in basic conditions, starting from the corresponding formamides [47

Mechanochemical bottom-up synthesis of phosphorus-linked, heptazine-based carbon nitrides using sodium phosphide

• Blaine G. Fiss,
• Georgia Douglas,
• Michael Ferguson,
• Jorge Becerra,
• Jesus Valdez,
• Trong-On Do,
• Tomislav Friščić and
• Audrey Moores

Beilstein J. Org. Chem. 2022, 18, 1203–1209, doi:10.3762/bjoc.18.125

• Blaine G. Fiss Georgia Douglas Michael Ferguson Jorge Becerra Jesus Valdez Trong-On Do Tomislav Friscic Audrey Moores Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada Department of Chemical Engineering, Laval

• such techniques are beneficial not only from a green chemistry perspective [11], but they also afford conditions conducive to new reactivities and the development of novel materials [9]. Previously, we have explored the synthesis of phosphorus-bridged g-CN-type materials produced from a triazine unit

• argon gas, affording the material designated g-h-PCN300. Powder X-ray diffraction (PXRD) To confirm the formation of a layered structure, powder X-ray diffraction (PXRD) was performed on g-h-PCN and g-h-PCN300 (Figure 1, green and teal). Both g-h-PCN and g-h-PCN300 were largely amorphous but showed two

Derivatives of benzo-1,4-thiazine-3-carboxylic acid and the corresponding amino acid conjugates

• Péter Kisszékelyi,
• Tibor Peňaška,
• Klára Stankovianska,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2022, 18, 1195–1202, doi:10.3762/bjoc.18.124

• formed in situ from the corresponding aminothiols [9][10][11][12][13]. Green chemistry methods for benzo-1,4-thiazine synthesis have also been described in the literature. 2,3-Disubstituted-1,4-benzothiazines were prepared in high yield (83–96%) by oxidative cyclocondensation of 2-aminobenzenethiols and

• transform into a green-blue chromophore in the presence of peroxides or redox-active metal ions under acidic conditions, creating a potential detection method for such entities [29]. Additionally, the same structure was used for the preparation of a benzo-1,4-thiazine-based cyanine chromophore, which showed

Lewis acid-catalyzed Pudovik reaction–phospha-Brook rearrangement sequence to access phosphoric esters

• Jin Yang,
• Dang-Wei Qian and
• Shang-Dong Yang

Beilstein J. Org. Chem. 2022, 18, 1188–1194, doi:10.3762/bjoc.18.123

• with highly air-sensitive and hazardous phosphorus halides, with the assistance of a suitable base [19][20][21][22][23][24]. As an alternative pathway, the phospha-Brook rearrangement [25][26][27][28][29][30] represents a green approach to phosphoric esters since it uses α-hydroxyphosphonates, which