Group 13 exchange and transborylation in catalysis

• Dominic R. Willcox and
• Stephen P. Thomas

Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28

• for catalysis, due to the generally higher abundance and lower toxicity of these elements. Group 13 elements have a rich catalogue of stoichiometric addition reactions to unsaturated bonds but cannot undergo the redox chemistry which underpins transition-metal catalysis. Group 13 exchange reactions

• after In‒N/B‒H exchange with HBpin gave a borylimine iron complex 110. A second hydroelementation and In‒N/B‒H exchange gave the bisborylamine 113 and regenerated the HInCl2 107 co-catalyst (Scheme 27). Conclusion Increasing concerns over the sustainability and toxicity of many transition-metal

Continuous flow synthesis of 6-monoamino-6-monodeoxy-β-cyclodextrin

• János Máté Orosz,
• Dóra Ujj,
• Petr Kasal,
• Gábor Benkovics and
• Erika Bálint

Beilstein J. Org. Chem. 2023, 19, 294–302, doi:10.3762/bjoc.19.25

• and non-toxicity. However, partial hydrolysis of the p-toluenesulfonyl group takes place, so the final product is always contaminated with native β-CD (1). Despite this, the product mixture after precipitation from acetone was used in the next reaction step and a proper purification of the targeted

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

• reasons [1]. Halogenated solvents such as chlorobenzene or dichloromethane are widely used in polymer production, but their toxicity and high energy consumption for synthesis make them unwanted for widespread commercial use. Many other dipolar solvents such as dimethyl sulfoxide (DMSO), N,N

• melting point, and difficulties during handling are challenges for a wider application [33] along with some residual toxicity. Alternatively, Vergaelen and co-workers investigated ethyl acetate as a solvent for the CROP of 2-ethyl-2-oxazoline (EtOx) [23]. However, ethyl acetate is not a suitable solvent

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

• carbon–carbon iron-catalyzed cross coupling as a key step were developed, capitalizing on the low toxicity and the cheap cost of this abundant metal [10]. For instance, in 1971, Kochi developed an iron-catalyzed alkyl–alkenyl cross-coupling reaction between aliphatic Grignard reagents and vinyl bromides

• NMP as a co-solvent. Indeed, NMP recently proved to be of very high concern due to its acute toxicity, since it was classified as a reprotoxic reagent [16][17]. In order to circumvent this matter and develop new non-toxic and sustainable iron-mediated coupling transformations, efforts were put in the

• , dialkyl phosphates used as leaving groups lead to overall transformations which display a poor atom economy. Moreover, diethyl chlorophosphate (DCP), used as a classic starting material in the dienol phosphates synthesis, is also registered under REACH regulation, and its use brings several toxicity

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

• hydrolyzed to the ineffective carboxylate form at basic pH, resulting in decreased clinical efficacy and increased drug-related toxicity. As only the lactone structure of CPT can be transferred through cellular membranes and inhibit topoisomerase I, it is the functional component of CPT lactone form that is

• cells. It is suggested that this difference is due to various reasons, such as decreased drug penetration, development of hypoxic nuclei, and decreased growth [65]. The findings are explained by the differences between conventional cell culture and 3D tumor spheroids. The predicted toxicity/efficacy is

• recent study, cellular cholesterol is directly involved in T cell-mediated cytotoxicity. Cancer cells with cholesterol-rich plasma membranes can evade the immune system by blocking toxicity caused by T cells, but as the amount of cholesterol in the tumor decreases, T cell-mediated cytotoxicity rises [72

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

• the perception that radicals cannot be selectively used took place with the introduction of tin hydrides in organic synthesis. Apart from the lower toxicity compared to organomercury reagents, the stability and longevity of tin-centered radicals allowed better propagation of radical chain reactions

Digyalipopeptide A, an antiparasitic cyclic peptide from the Ghanaian Bacillus sp. strain DE2B

• Adwoa P. Nartey,
• Aboagye K. Dofuor,
• Kofi B. A. Owusu,
• Anil S. Camas,
• Hai Deng,
• Marcel Jaspars and
• Kwaku Kyeremeh

Beilstein J. Org. Chem. 2022, 18, 1763–1771, doi:10.3762/bjoc.18.185

• IC50 0.96 µM) and 4.85 µM (amphotericin B IC50 4.87 µM), respectively. Furthermore, digyalipopeptide A (1) produced IC50 values of 10.07 µM (ampicillin IC50 0.18 µM) and 10.01 µM (ampicillin IC50 1.53 µM) for Staphylococcus aureus and Shigella sonnei, respectively. The selectivity and toxicity profile

• 10.01, 18.71, and 10.01 µM, respectively. The laboratory standard itself produced IC50 of 1.53 µM for Shigella sonnei, Shigella flexneri 1.76 µM, and Staphylococcus aureus 0.18 µM, respectively (Table 3). The selectivity and toxicity profile of compound 1 was also investigated using normal cell lines

Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements

• Alexios I. Vicatos,
• Zakiena Hoossen and
• Mino R. Caira

Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184

• relatively low cost of these CDs and in particular the low toxicity of γ-CD are advantageous for potential drug delivery. Furthermore, the amorphous nature of highly water-soluble CD derivatives (e.g., hydroxypropyl-CD and sulfobutyl ether CD) precludes their formation of crystalline inclusion complexes

Total synthesis of grayanane natural products

• Nicolas Fay,
• Rémi Blieck,
• Cyrille Kouklovsky and
• Aurélien de la Torre

Beilstein J. Org. Chem. 2022, 18, 1707–1719, doi:10.3762/bjoc.18.181

• of each strategy, as well as the challenges remaining to be tackled. Keywords: enantioselectivity; grayananes; oxidation; 1,2-shift; total synthesis; Introduction The Ericaceae are a large plant family, with over 4250 known species all around the world [1]. While Ericaceae’s toxicity has been known

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

• include their synthetic availability, wide opportunities for rational structure design, generally lower toxicity, air and water stability, metal-free nature, and the scalability of their production and use. These features have made organocatalysis a prospering area and an even more promising methodology

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

• hydrophobic cavity inside the molecule, while all hydrophilic hydroxy groups are arranged outside the cavity. This feature determines the main practical application of CDs as supramolecular hosts for host–guest interaction. Due to their low cost, low toxicity, and good complexation ability, they are

New triazole-substituted triterpene derivatives exhibiting anti-RSV activity: synthesis, biological evaluation, and molecular modeling

• Elenilson F. da Silva,
• Krist Helen Antunes Fernandes,
• Denise Diedrich,
• Jessica Gotardi,
• Marcia Silvana Freire Franco,
• Carlos Henrique Tomich de Paula da Silva,
• Ana Paula Duarte de Souza and
• Simone Cristina Baggio Gnoatto

Beilstein J. Org. Chem. 2022, 18, 1524–1531, doi:10.3762/bjoc.18.161

• VERO, HEP2, B16F10, and A549 non-infected cells. The therapeutic index (TI) is a comparison between the amount of a compound that causes a therapeutic effect and the amount that causes toxicity. Although all derivatives showed a reasonable cytotoxic effect in non-infected cells, compound 8 was the most

• antiviral activity against RSV. Molecular docking Therefore, owing to its excellent level of activity and lack of toxicity, evidenced by a high TI, we selected compound 8 for further studies, starting with the elucidation of the mechanism of action. Our hypothesis on the study of the mechanism of action

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

• whose physical and chemical properties and pharmacological activities could be improved by structural modifications are used as important antibacterial agents. The compounds are characterized by high efficiency, low toxicity, and low residue, and play an important role in pharmacy and medicine

On drug discovery against infectious diseases and academic medicinal chemistry contributions

• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 1355–1378, doi:10.3762/bjoc.18.141

• of work. Then, the necessary feedback from the assays along with quite a few controls and further evaluations (i.e., from ligand binding thermodynamics, if the target is known, to cellular toxicity and all the way to early ADME) will also take some time. In other words, organic synthesis remains one

B–N/B–H Transborylation: borane-catalysed nitrile hydroboration

• Filip Meger,
• Alexander C. W. Kwok,
• Franziska Gilch,
• Dominic R. Willcox,
• Alex J. Hendy,
• Kieran Nicholson,
• Andrew D. Bage,
• Thomas Langer,
• Thomas A. Hunt and
• Stephen P. Thomas

Beilstein J. Org. Chem. 2022, 18, 1332–1337, doi:10.3762/bjoc.18.138

• research into the development of new catalytic methodologies, specifically those that use Earth-abundant and low toxicity elements, as an alternative to transition-metal catalysis [9][10]. Using metal-free catalytic systems, including boron-based catalysts, circumvents some of the issues associated with

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• ]. This palladium-catalysed cross coupling is preferred over a Stille cross-coupling due to the high toxicity of organotin reagents [37]. Moreover, purification of compound 25 is facile since it can be used for further reactions after re-precipitation in petroleum ether. In a manner similar to [35], it is

A trustworthy mechanochemical route to isocyanides

• Francesco Basoccu,
• Federico Cuccu,
• Federico Casti,
• Rita Mocci,
• Claudia Fattuoni and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 732–737, doi:10.3762/bjoc.18.73

• synthetic pathways usually involve employing strong conditions and toxic reagents. The current paper intends to provide a conceptually innovative synthetic protocol for mechanochemical isocyanide preparation, simultaneously lowering the related reagents' toxicity and improving their purification in a

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• , they are less common due to their inherent toxicity and ease of oxidation. Another branch of research involving SPIONs focuses on developments in nanoscience, nanomedicine, and nanoparticle-assisted imaging, diagnosis, and drug delivery [4][5][6][7], an area that is not covered in this report. Review 1

The asymmetric Henry reaction as synthetic tool for the preparation of the drugs linezolid and rivaroxaban

• Martin Vrbický,
• Karel Macek,
• Jaroslav Pochobradský,
• Jan Svoboda,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2022, 18, 438–445, doi:10.3762/bjoc.18.46

• catalysts based on copper(II) complexes with chiral nitrogen ligands were chosen. Generally, chiral copper complexes possess many advantages valuable for the pharmaceutical industry. They exhibit low toxicity (compared to other metal-based complexes) and many of them exist in forms suitable for recycling

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• , this is a good synthetic path, since PIFA has a low toxicity and it is easily accessible. Subsequently, Wójtowicz and co-workers studied a series of experiments in order to test the oxidative action of tert-butyl hydroperoxide and the role of organoselenes as catalysts in the demethylation reaction of

Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions

• Surendran Amrutha,
• Sankaran Radhika and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31

• due to a reduced toxicity and low cost. In addition, multiwalled carbon nanotubes are also used as desirable polymers. However, nanoscale materials may pose a considerable health risk due to the gradual increase in surface area per mass unit. A novel type of environmentally benign, economical, and

Flow synthesis of oxadiazoles coupled with sequential in-line extraction and chromatography

• Kian Donnelly and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 232–239, doi:10.3762/bjoc.18.27

• oxadiazoles [33]. While this method provided the products in high yields, it required the use of super-stoichiometric quantities of iodine, which is potentially toxic and corrosive. This potential toxicity in combination with the requirement for the subsequent removal of excess iodine and potentially

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• permeability [1][2][3]. Hence, peptide-based drugs became of high interest because of their high selectivity combined with low toxicity. Cross-linking of side chain residues results in constrained conformations and can be used to stabilise α-helical secondary structures. This technique is called peptide

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• Togni’s reagent, is ideal because of its stability, low toxicity, and cost [148]. In terms of scope, the electronic nature of the benzoic acid had no effect on the reaction. On the other hand, only electron-rich styrene derivatives

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

• Nicolai Wippert,
• Martin Nieger,
• Claudine Herlan,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2021, 17, 2773–2780, doi:10.3762/bjoc.17.187

• standardized MTT assays [41] to evaluate if the newly accessible compounds of type 5 and their precursors could become interesting target molecules for biological investigations or if the compounds show high toxicity, which might prevent their use. We monitored cytotoxicity at six different concentrations

• , characterized by two aromatic moieties at both variable positions R1 and R2. In Table S3 (Supporting Information File 1), the results for compounds 5, 9, 12, and 13 are summarized allowing the direct comparison of the toxicity of the four compound classes with respect to 5 different residues R1. The full data

• of the toxicity studies for all obtained compounds are given in Supporting Information File 1, Tables S1–S3. Comparing the 20 derivatives depicted in Figure 3 reveals that compounds of the classes 5, 9, and 12 are in general less toxic than the respective compounds of class 13, at least with respect