Facile one-pot reduction of β-nitrostyrenes to phenethylamines using sodium borohydride and copper(II) chloride

• Laura D’Andrea and
• Simon Jademyr

Beilstein J. Org. Chem. 2025, 21, 39–46, doi:10.3762/bjoc.21.4

• substituted β-nitrostyrenes. This one-pot procedure allows the quick isolation of substituted β-nitrostyrene scaffolds with 62–83% yield under mild conditions, without the need for special precautions, inert atmosphere, and time-consuming purification techniques. Keywords: 2C-X; CuCl2; NaBH4; β-nitrostyrene

• suspensions and precipitation of the starting materials, make these solvents unsuitable for this reaction and the isolation of the products troublesome. The use of 2-propanol/water (2:1), together with the application of heat, ensures optimal solubility of the species involved. Moreover, the workup procedure

Emerging trends in the optimization of organic synthesis through high-throughput tools and machine learning

• Pablo Quijano Velasco,
• Kedar Hippalgaonkar and
• Balamurugan Ramalingam

Beilstein J. Org. Chem. 2025, 21, 10–38, doi:10.3762/bjoc.21.3

• , differing from established isolation and separation techniques, holds the promise of not only enhancing the efficiency of HTE flow synthesis but also paving the way for more sustainable growth in this research area. Autonomous self-optimizing flow reactors Autonomous self-optimizing flow reactors (ASFRs

Reactivity of hypervalent iodine(III) reagents bearing a benzylamine with sulfenate salts

• Beatriz Dedeiras,
• Catarina S. Caldeira,
• José C. Cunha,
• Clara S. B. Gomes and
• M. Manuel B. Marques

Beilstein J. Org. Chem. 2024, 20, 3281–3289, doi:10.3762/bjoc.20.272

• from the simultaneous formation of sulfinamide 6ea also isolated in this reaction for the first time (both in trace amounts). Reaction mechanism The inability to detect sulfinamide 6 and the isolation of sulfonamide 5, along with other byproducts (3, 4, and 7), stimulated us to propose a plausible

Ceratinadin G, a new psammaplysin derivative possessing a cyano group from a sponge of the genus Pseudoceratina

• Shin-ichiro Kurimoto,
• Kouta Inoue,
• Taito Ohno and
• Takaaki Kubota

Beilstein J. Org. Chem. 2024, 20, 3215–3220, doi:10.3762/bjoc.20.267

• discovery of an additional psammaplysin derivative, ceratinadin G (1) (Figure 1). This paper details the isolation, structural elucidation, and biological activity of compound 1. Results and Discussion The marine sponge Pseudoceratina sp., collected in Okinawa, Japan, was initially extracted with MeOH

• ), as well as additional signals not matching those of any known psammaplysin derivatives. Further separation of this fraction using C18 HPLC led to the isolation of ceratinadin G (1, 0.4 mg, 3.2 × 10−4%) along with psammaplysin F (2) [10][11][12]. Ceratinadin G (1) was isolated as an optically active

• 49.8 ppm were used as internal references. Mass spectra were acquired on a JEOL JMS-T100LP spectrometer. Flash column chromatography was performed using a Biotage Isolera flash purification system. Extraction and isolation The EtOAc-soluble material (2.45 g) of the methanol extract (38.06 g) from the

Discovery of ianthelliformisamines D–G from the sponge Suberea ianthelliformis and the total synthesis of ianthelliformisamine D

• Sasha Hayes,
• Yaoying Lu,
• Bernd H. A. Rehm and
• Rohan A. Davis

Beilstein J. Org. Chem. 2024, 20, 3205–3214, doi:10.3762/bjoc.20.266

• aeruginosa biofilm inhibitors and antibiotic enhancers. Large-scale extraction and isolation studies resulted in the discovery of four new and minor natural products, ianthelliformisamines D–G (4–7) and the known steroid, aplysterol (8). Compounds 4–7 were fully characterised following 1D/2D NMR, MS and UV

• describe the large-scale extraction, isolation, and structure elucidation of four new metabolites, ianthelliformisamines D–G (4–7). Additionally, we report the isolation of the known natural products, aplysterol (8) and ianthelliformisamines A–C (1–3). Owing to the novelty of ianthelliformisamine D (4) we

• HPLC (RP-HPLC), which led to the purification of the known metabolites, ianthelliformisamines A–C (1–3) [7] and aplysterol (8) [13], and four new natural products, ianthelliformisamines D–G (4–7) (Figure 1). This extraction and isolation process was repeated twice to obtain sufficient quantities of the

Synthesis of the 1,5-disubstituted tetrazole-methanesulfonylindole hybrid system via high-order multicomponent reaction

• Cesia M. Aguilar-Morales,
• América A. Frías-López,
• Nadia V. Emilio-Velázquez,
• Alejandro Islas-Jácome,
• Angelica Judith Granados-López,
• Jorge Gustavo Araujo-Huitrado,
• Yamilé López-Hernández,
• Hiram Hernández-López,
• Luis Chacón-García,
• Jesús Adrián López and
• Carlos J. Cortés-García

Beilstein J. Org. Chem. 2024, 20, 3077–3084, doi:10.3762/bjoc.20.256

• studies, we employed benzaldehyde derivatives with various stereoelectronic decoration, excluding aliphatic ones due to their decreased reactivity resulting in failures to proceed [24][25][26][27]. Commercially available isocyanides utilized were cyclohexyl and tert-butyl isocyanide. Notably, an isolation

Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

• Thomas Ma and
• John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

• . Fractionation is an iterative process guided by screening for the desired bioactivity until the isolation of a pure compound. This workflow was invented by Selman Waksman and has facilitated the identification of the vast majority of natural products known to date. However, it has fallen out of favor due to

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• . A size-complementary rotaxane contains axle-end groups that are as large as the wheel cavity. Thus, it is sufficiently stable for isolation under ambient conditions, although a certain stimulus, e.g., heat or the addition of a base, can induce the deslipping reaction to degrade itself as each

• reaction confirmed that the deslipping of [3]rotaxane 3 was approximately 10 times faster than that of [2]rotaxane 6, offering a local maximum of the yield of [2]rotaxane species in the developing process (approximately 80% by the theoretical calculation) and enabling the isolation of [2]rotaxane during

Synthesis of fluorinated acid-functionalized, electron-rich nickel porphyrins

• Mike Brockmann,
• Jonas Lobbel,
• Lara Unterriker and
• Rainer Herges

Beilstein J. Org. Chem. 2024, 20, 2954–2958, doi:10.3762/bjoc.20.248

• , see Scheme 1). In order to break the symmetry and to generate the acid function only on one side, benzyl protection was performed. From diols 1, 2, and 3 statistical mixtures of unprotected, mono-, and di-protected products were obtained, from which the isolation of the desired mono-protected products

• bicarbonate (NaHCO₃) provided acids 7, 8, and 9. A byproduct is obtained during oxidation and it is assumed that this is the molecule oxidized at the benzyl position (see Supporting Information File 1, compounds 35–40). Work-up and isolation proved to be difficult, and therefore, the acids were directly

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• the reaction to proceed under gentle conditions. This prevents the subsequent transformation of the obtained S-aryl xanthates, thereby facilitating their isolation with satisfactory to excellent yields. During the assessment of the reaction's versatility, first variously substituted (4-anisyl)(aryl

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• material in Europe (Scheme 1). It is obtained by extraction and isolation of the colorless indole-O-glycoside indicane which is then hydrolyzed to give indoxyl. The latter undergoes oxidative dimerization to provide indigo. In the 19th century, syntheses of indigo were developed which made the pigment

• , indirubin, and isoindigo which can be regarded as blue, red, and yellow sugars, respectively. Review Indigo-N-glycosides (blue sugars) In 2002, Laatsch and Maskey reported the isolation of the akashins A, B and C, indigo-N-glycosides, from terrestric Streptomyces (Scheme 2) [17][18]. These natural products

Synthesis of tricarbonylated propargylamine and conversion to 2,5-disubstituted oxazole-4-carboxylates

• Kento Iwai,
• Akari Hikasa,
• Kotaro Yoshioka,
• Shinki Tani,
• Kazuto Umezu and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2024, 20, 2827–2833, doi:10.3762/bjoc.20.238

•  3) [13][14]. To a dry THF solution of adduct 4a, butyllithium was added, and the reaction mixture was stirred at −78 °C for 5 min. Following the addition of acetic acid, the reaction mixture was concentrated and subjected to silica gel column chromatography, resulting in the isolation of ethyl 5

Mechanochemical difluoromethylations of ketones

• Jinbo Ke,
• Pit van Bonn and
• Carsten Bolm

Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235

• ketones reacted well too. Accordingly, 3j was obtained in 42% yield. Enone 1k gave 3k in 51% yield, and after isolation by column chromatography the product was obtained in 13% yield. Difluoromethyl enol ether 3l was formed from diketone 1l in 25% yield. Finally, conversions of the two cyclic ketones 1m

Young investigators in natural products chemistry, biosynthesis, and enzymology

• Jeffrey D. Rudolf,
• Lena Barra and
• Takayoshi Awakawa

Beilstein J. Org. Chem. 2024, 20, 2720–2721, doi:10.3762/bjoc.20.229

• , Japan 10.3762/bjoc.20.229 There is just something about natural products. When staring at these structurally complex molecules produced by diverse organisms on our planet, one may wonder why a particular natural product is made, how it is made, how I can make it, or how I can use it. The isolation and

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

• Ruben Manuel Figueira de Abreu,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

• investigation or modulation of desired properties. Conclusion In summary, we have developed the synthesis of novel polycyclic uracil-based compounds. Careful optimisation of the reaction conditions led to the isolation of the desired products in excellent to moderate yields. The developed methodology tolerates

Transition-metal-free decarbonylation–oxidation of 3-arylbenzofuran-2(3H)-ones: access to 2-hydroxybenzophenones

• Bhaskar B. Dhotare,
• Seema V. Kanojia,
• Chahna K. Sakhiya,
• Amey Wadawale and
• Dibakar Goswami

Beilstein J. Org. Chem. 2024, 20, 2655–2667, doi:10.3762/bjoc.20.223

• . However, it must be noted that the yields recorded in Table 1 are isolated yields. For the sake of eliminating errors in isolation, we have carried out every reaction in triplicate, and have considered the average yield as the isolated yield. Earlier, Qui et al. reported [2] that a transition-metal

The scent gland composition of the Mangshan pit viper, Protobothrops mangshanensis

• Jonas Holste,
• Paul Weldon,
• Donald Boyer and
• Stefan Schulz

Beilstein J. Org. Chem. 2024, 20, 2644–2654, doi:10.3762/bjoc.20.222

• ) were observed with similar mass spectra. The amount of secretion available and the complex mixture did not allow for the isolation of enough material for NMR analysis. Therefore, for the structure elucidation of these unknown compounds, we used different analytical methods, including GC–MS, GC–IR, and

Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

• materials, it is important that the data obtained from such techniques cannot be used in isolation. For example, a wide variety of models are available to characterise scattering data, however, solving the equations leads to multiple solutions. With scattering, the ‘best’ model is often chosen from the fit

Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids

• Andrey N. Komogortsev,
• Constantine V. Milyutin and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217

• method for the synthesis of a wide range of (3E,5E)-3-(1-hydroxyethylidene)-5-(5-oxopyrrolidin-2-ylidene)furan-2,4(3H,5H)-diones was elaborated. The advantages of the presented protocol are easily available starting compounds and simple isolation of the target products without chromatographic

Transition-metal-free synthesis of arylboronates via thermal generation of aryl radicals from triarylbismuthines in air

• Yuki Yamamoto,
• Yuki Konakazawa,
• Kohsuke Fujiwara and
• Akiya Ogawa

Beilstein J. Org. Chem. 2024, 20, 2577–2584, doi:10.3762/bjoc.20.216

• also tolerable, and the corresponding products 3i and 3j were selectively obtained in moderate yields. Notably, the bulky 2,4,6-trimethylphenyl group of bisumuthine 1l did not inhibit the transformation, and the boronate 3l was obtained in 78% yield. The isolation of arylboronates 3c, 3i, and 3j was

• somewhat difficult due to strong adsorption or decomposition on silica gel. Since some arylboronates are somewhat unstable, it is desirable to synthesize such compounds and then use them in a one-pot manner for the following reactions without isolation. To gain insight into the reaction pathways, several

HFIP as a versatile solvent in resorcin[n]arene synthesis

• Hormoz Khosravi,
• Valeria Stevens and
• Raúl Hernández Sánchez

Beilstein J. Org. Chem. 2024, 20, 2469–2475, doi:10.3762/bjoc.20.211

• ) use of 2-substituted electron-poor resorcinols with aldehydes larger than acetaldehyde produce intractable mixtures leading to no product isolation [9], in turn access to halogenated or deactivated electron-poor resorcin[n]arenes typically require an extra step as shown in Scheme 1b [8][56][57][58][59

Photoredox-catalyzed intramolecular nucleophilic amidation of alkenes with β-lactams

• Valentina Giraldi,
• Giandomenico Magagnano,
• Daria Giacomini,
• Pier Giorgio Cozzi and
• Andrea Gualandi

Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210

• well known as a potent β-lactamase inhibitor [33][34]. It is produced by the filamentous bacterium Streptomyces clavuligerus, but in low yield. Various clavams 2–5 have been identified (Figure 2B), either through isolation as natural metabolites or obtained by synthetic methods [35][36][37][38][39][40

• 8d exhibited an enhancement in reaction diastereoselectivity, resulting in the isolation of product 11d with a dr of 6.7:1 in favor of the trans-diastereoisomer. Remarkably, the formation of a fully substituted quaternary center was possible, as observed for the product 11g, where the trans

• starting from succinimide (Scheme 3). Through a simple reaction in toluene at 80 °C in the presence of Zn(OAc)2, the hemiaminal derivative 13 underwent substitution with cinnamyl alcohol, resulting in the isolation of 14 with a satisfactory yield. Under optimized reaction conditions, the photocatalytic

Improved deconvolution of natural products’ protein targets using diagnostic ions from chemical proteomics linkers

• Andreas Wiest and
• Pavel Kielkowski

Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199

• . Acquisition techniques benefit from possible multistage ion separation and isolation, and diverse fragmentation techniques. All of that is nowadays combined in one instrument to provide greater flexibility of the spectra acquisition setup [7][8][9][10][11][12][13][14][15][16]. Given the sheer amount of data

gem-Difluorination of carbon–carbon triple bonds using Brønsted acid/Bu₄NBF₄ or electrogenerated acid

• Mizuki Yamaguchi,
• Hiroki Shimao,
• Kengo Hamasaki,
• Keiji Nishiwaki,
• Shigenori Kashimura and
• Kouichi Matsumoto

Beilstein J. Org. Chem. 2024, 20, 2261–2269, doi:10.3762/bjoc.20.194

• the case of an aliphatic terminal alkyne, such as dec-1-yne (1d), the 19F NMR study indicated 46% yield with method A (Table 2, entry 5), but it was difficult to purify and isolate product 2d because of the low molecular weight. Scale up conditions of method A, for the purpose of the isolation, led to

• the formation of the corresponding product 2d in 40% yield as the 19F NMR analysis (Table 2, entry 6), but the isolation of 2d was difficult [54]. Method B gave 2d in 35% yield, as shown by the 19F NMR analysis (Table 2, entry 7). Another alkyne, namely, octadec-1-yne (1e), was found to be a nice

Heterocycle-guided synthesis of m-hetarylanilines via three-component benzannulation

• Andrey R. Galeev,
• Maksim V. Dmitriev,
• Alexander S. Novikov and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2024, 20, 2208–2216, doi:10.3762/bjoc.20.188

• reaction in the presence of molecular sieves and 1.5-fold excess of aniline (conditions B) dramatically reduced the reaction time to 1 d, allowing isolation of diarylamine 3ac in 75% yield (Scheme 2). Next, we started to screen various heterocyclic 1,3-diketones with the model amine series. The reaction of