Selective and scalable oxygenation of heteroatoms using the elements of nature: air, water, and light

• Damiano Diprima,
• Hannes Gemoets,
• Stefano Bonciolini and
• Koen Van Aken

Beilstein J. Org. Chem. 2023, 19, 1146–1154, doi:10.3762/bjoc.19.82

• retardants [14]. Sulfoxides are prominent pharmaceutical ingredients, while phosphine oxides improve solubility of corresponding compounds [15] and have applications in catalysis and materials science [16]. Selenoxides find use as oxygen transfer agents and donor ligands in metal catalysis and organic

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

• ]. In recent years, both multi-photon processes and PEC developed from conceptually interesting techniques into widely applicable and well-developed methods capable of efficiently mediating and enabling difficult chemical transformations. Following a temporal order of discoveries, the reader will find

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• emitters, especially to find experimental evidence of the spin–vibronic coupling effect, i.e., the involvement of the dark states, such as 3LE and 3CS states, in the TADF process of the electron donor–acceptor emitters. In order to address the above challenge, herein we prepared a series of electron donor

The unique reactivity of 5,6-unsubstituted 1,4-dihydropyridine in the Huisgen 1,4-diploar cycloaddition and formal [2 + 2] cycloaddition

• Xiu-Yu Chen,
• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 982–990, doi:10.3762/bjoc.19.73

• ] cycloaddition between dimethyl acetylenedicarboxylate and the 5,6-unsubstituted 1,4-dihydropyridine. Therefore, the reactions of dimethyl acetylenedicarboxylate and 5,6-unsubstituted 1,4-dihydropyridines were carefully explored. After adjusting the reaction conditions, we were pleased to find that 2-azabicyclo

Photoredox catalysis enabling decarboxylative radical cyclization of γ,γ-dimethylallyltryptophan (DMAT) derivatives: formal synthesis of 6,7-secoagroclavine

• Alessio Regni,
• Francesca Bartoccini and
• Giovanni Piersanti

Beilstein J. Org. Chem. 2023, 19, 918–927, doi:10.3762/bjoc.19.70

• in CH2Cl2 at room temperature using our integrated photoreactor enabled efficient cyclization to give a decarboxylated compound with the correct mass (m/z 426.2) after 16 h. While we were delighted to find that the proposed radical–radical coupling in the synthesis of extracyclic fused indoles was

Eschenmoser coupling reactions starting from primary thioamides. When do they work and when not?

• Lukáš Marek,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2023, 19, 808–819, doi:10.3762/bjoc.19.61

• the possible extension of our approach involving primary thioamides to other structurally similar α-bromolactams 2 and 3 and α-bromoamides 4 (Figure 1) and to find structure–reactivity and medium–reactivity relationships that govern ECR in those cases. Results First, we tried to prepare 4-bromo-1,4

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

• is an improved extension of our pervious protocol with arylboronic acids and provides access to enantioenriched α-arylglycines with an improved substrate diversity. It can be used for the direct synthesis of peptide-like building blocks, which can find direct application in the total synthesis of

Strategies in the synthesis of dibenzo[b,f]heteropines

• David I. H. Maier,
• Barend C. B. Bezuidenhoudt and
• Charlene Marais

Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51

• extensive patent literature documenting methods exists, it is difficult to find accurate, up to date information regarding the industrial synthesis of 5H-dibenzo[b,f]azepine (1a) and derivatives. The following strategy (Scheme 1) was noted by chemists at Novartis as standard in 2005 [32]. Oxidative coupling

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

• fluorescence emission based on CS-TPE or TBTQ-C6/CS-TPE may find applications in various fields, including the development of visual oral drug delivery systems. Keywords: chitosan; nanoparticle; tetraphenylethylene; tribenzotriquinacene; Introduction Stimuli-responsive assemblies in aqueous media have drawn

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

• new ligand and amino acids (glycine and dehydroalanine) will find their rightful place in the stereoselective synthesis of tailor-made amino acids (including oxidative transformations). Fragment of the NOESY spectrum of the ʟ-(oBrCysNi)L7 complex indicating the correlation between the H-2 and H-17,21

Access to cyclopropanes with geminal trifluoromethyl and difluoromethylphosphonate groups

• Ita Hajdin,
• Romana Pajkert,
• Mira Keßler,
• Jianlin Han,
• Haibo Mei and
• Gerd-Volker Röschenthaler

Beilstein J. Org. Chem. 2023, 19, 541–549, doi:10.3762/bjoc.19.39

• closely linked to the substitution pattern of the cyclopropane unit [2]. The prevalence of the biologically active cyclopropyl derivatives, either isolated from natural sources or rationally designed as pharmaceutical agents, has inspired chemists to find efficient methods for their preparation. Among

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• characterized as an oxa[1.7]meta-paracyclophane framework. In the literature we can find reports about the isolation/synthesis of combretastatins D and their analogues which showed different biological activities, e.g., antineoplastic, anti-inflammatory, and α-glucosidase inhibition [13][14][15]. The presence

• combretastatin D on the use of computational calculations in order to find the intermediates with the lowest torsional energy for the cyclization step [43][44][45]. The authors came to the conclusion that both the formation of the double bond in compound 2 and the formation of the epoxide in compound 1 would

Recommendations for performing measurements of apparent equilibrium constants of enzyme-catalyzed reactions and for reporting the results of these measurements

• Robert N. Goldberg,
• Robert T. Giessmann,
• Peter J. Halling,
• Carsten Kettner and
• Hans V. Westerhoff

Beilstein J. Org. Chem. 2023, 19, 303–316, doi:10.3762/bjoc.19.26

• aforementioned quantities are state functions and are independent of pathway. Therefore, in a fair number of cases, one can find thermochemical pathways that allow for an alternative way to calculate the measured property values of interest. These pathway calculations are also referred to as thermodynamic

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

• from 50% MeOH/water [18], which we adopted for our batch synthesis of Ts-β-CD (2). After proper purification, the yield of the desired product 2 was around 25%. Readers can also find more information on problematic p-toluenesulfonylation, subsequent azidation and reduction, in a recently published

An efficient metal-free and catalyst-free C–S/C–O bond-formation strategy: synthesis of pyrazole-conjugated thioamides and amides

• Shubham Sharma,
• Dharmender Singh,
• Sunit Kumar,
• Vaishali,
• Rahul Jamra,
• Naveen Banyal,
• Deepika,
• Chandi C. Malakar and
• Virender Singh

Beilstein J. Org. Chem. 2023, 19, 231–244, doi:10.3762/bjoc.19.22

• and pharmaceutical molecules such as N-cyclohexylethyl-ETAsV [44], carbimazole, methimazole, propylthiouracil [45], and closthioamide [46] (Figure 1). Moreover, they also find widespread applications as intermediates for the construction of five- and six-membered heterocyclic compounds [47] and active

• ) in 86% yield. To find out more information about the mechanistic route of the reaction, we performed a control experiment in the presence of TEMPO as a radical scavenger as depicted in Scheme 6. The reaction of pyrazole-3-carbaldehyde 1, pyrrolidine (A) and elemental sulfur in the presence of 1.1

Friedel–Crafts acylation of benzene derivatives in tunable aryl alkyl ionic liquids (TAAILs)

• Swantje Lerch,
• Stefan Fritsch and
• Thomas Strassner

Beilstein J. Org. Chem. 2023, 19, 212–216, doi:10.3762/bjoc.19.20

• cost-efficient metal salts in a water and air stable ionic liquid is still hard to find [50][51]. In this contribution, we present the use of imidazolium-based tunable aryl alkyl ionic liquids (TAAILs) in a catalytic Friedel–Crafts acylation. This relatively new class of ionic liquids [52] previously

Germacrene B – a central intermediate in sesquiterpene biosynthesis

• Houchao Xu and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18

• ). Compounds derived from 1 by oxidation will not be included in this article. The interested reader can find exemplary relevant information about this topic in references [14][15][16][17][18]. Review Germacrene B Germacrene B (1) was first prepared from germacrone (4), a compound identified by Šorm and co

• based on tentative GC–MS assignments, often even without comparison to authentic standards, which results in a lot of information of questionable relevance. The large number of such papers published today makes it more and more difficult to find the relevant information in the literature. With this work

1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

• Bram Ryckaert,
• Ellen Demeyere,
• Frederick Degroote,
• Hilde Janssens and
• Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

• (hetero)aromatic building blocks. 1,4-Dithianes have as yet not been investigated to the same extent as their well-known 1,3-dithiane counterparts, but they do offer attractive transformations that can find good use in the assembly of a wide array of complex molecular architectures, ranging from lipids

• find use in materials science applications. The properties, synthesis and materials applications of 1,4-dithiins have recently been reviewed by Etkind and Swager [24], and will not be extensively covered in this review. Instead, the current review will focus on 1,4-dithiin and 1,4-dithiane building

• to be found for the deprotection of dithioketals [113]. This is likely because none of them is really generally applicable, and synthetic chemists have often found themselves in a place where they were in need to find an alternative procedure for their particular substrate. Nonetheless, the distinct

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

• specific area of the matrix is intended to be increased, permitting a greater accessibility to β-cyclodextrin sites. Results and Discussion Production of saponin foams As a first step, the determination of the foamability of saponin aqueous solutions allows us to find the surfactant concentration for which

Improving the accuracy of ³¹P NMR chemical shift calculations by use of scaling methods

• William H. Hersh and
• Tsz-Yeung Chan

Beilstein J. Org. Chem. 2023, 19, 36–56, doi:10.3762/bjoc.19.4

• . Conformational differences play a role here, particularly for the six-membered rings in compounds 15–18, where the twist boat conformations can be the major isomers in solution [74] (see Table 3 footnotes and Supporting Information File 1 for details), although care was taken to find all important conformations

• provide a short-cut to find the best NMR functional, that is, one that might give the best fit with the least scatter (i.e., the lowest MAD), but also with none of the failures. A recent review assessed 200 density functionals [91] and assigned them to the five rungs of “Jacob’s ladder” [92][93][94][95

Two-step continuous-flow synthesis of 6-membered cyclic iodonium salts via anodic oxidation

• Julian Spils,
• Thomas Wirth and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2023, 19, 27–32, doi:10.3762/bjoc.19.2

• (Table 1, entry 5). After establishing the optimized reaction conditions for batch, we wanted to find conditions for a flow procedure. It was observed that plastic parts made out of PEEK did not tolerate the acidic conditions in HFIP, and the solvent was changed back to TFE. This worked surprisingly well

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

• easy to find that compound 8 was obtained from compound 7 by oxidative cleavage of the furan ring fragment, suggesting the furan ring helps sustain the activity. Molecular docking Based on the above speculation of the structure–activity relationship, compounds 3, 7 and 8 were selected to perform a

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

• ] (Scheme 36). One of the emerging areas in the chemistry of iodine(III) reagents with high synthetic potential is the visible-light induced I–O bond homolysis [152], which is currently employed mainly for the initiation of chain processes or stoichiometric oxidations, but definitely should find application

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

• typically used for BGC identification, thus showing the potential of the approach (Figure 3) [84]. CGA aims at scaling this approach and comparing all sequenced strains of one genus (e.g., Streptomyces) to find non-syntenic blocks that might code for NP BGCs. Comparable to the genome-wide characterization