A versatile route towards 6-arylpipecolic acids

• Erich Gebel,
• Cornelia Göcke,
• Carolin Gruner and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 1104–1115, doi:10.3762/bjoc.21.88

• -inducing properties in peptides [22][23][24]. Furthermore, derivatives of pipecolic acid are known for their bioactivity as secondary metabolites [25][26][27] and for being building blocks for piperidine alkaloids [28] with a variety of uses. Results and Discussion Addressing specific positions in the ring

Synthesis of pyrrolo[3,2-d]pyrimidine-2,4(3H)-diones by domino C–N coupling/hydroamination reactions

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

Beilstein J. Org. Chem. 2025, 21, 1010–1017, doi:10.3762/bjoc.21.82

• instance, deazapurines represent heterocyclic fused pyrimidine bases which have found special attention, due to their widespread occurrence in natural alkaloids exhibiting various biological properties. For example, cadeguomycin (A), tubercidin (B), and toyocamycin (C) show antibiotic properties, while

Recent total synthesis of natural products leveraging a strategy of enamide cyclization

• Chun-Yu Mi,
• Jia-Yuan Zhai and
• Xiao-Ming Zhang

Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81

• cyclization modes that provide entries to various N-heterocycles, some of which serve as key structural motifs in natural alkaloids. This review highlights recent advancements in enamide-based cyclization reactions, including enamide–alkyne cycloisomerization, [3 + 2] annulation, and polycyclization, with a

• have attracted considerable attention due to their promise in the total synthesis of alkaloids [16]. Notably, these valuable compounds can be employed as efficient synthons in enamide–alkyne cycloisomerization, [n + m] cycloadditions, pericyclic reactions, and radical cyclizations. A comprehensive

• review of these advancements up until 2015 has already been documented [16]. In this review, recent breakthroughs of these enamide cyclizations will be surveyed from the viewpoint of natural product synthesis. Leveraging the enamide–alkyne cycloisomerization cyclizations, Lycopodium alkaloids

Studies on the syntheses of β-carboline alkaloids brevicarine and brevicolline

• Benedek Batizi,
• Patrik Pollák,
• András Dancsó,
• Péter Keglevich,
• Gyula Simig,
• Balázs Volk and
• Mátyás Milen

Beilstein J. Org. Chem. 2025, 21, 955–963, doi:10.3762/bjoc.21.79

• DC is a widely distributed sedge which can be mainly found in the Central and South-Eastern European region. It contains several alkaloids, including β-carboline alkaloids (S)-brevicolline (S-(1)) and brevicarine (2, Figure 1) as the two main components [1][2][3]. Our long-standing interest in the

• chemistry of β-carbolines [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] has now focused our attention on these two alkaloids. In a recent publication we disclosed a new total synthesis of racemic brevicolline ((±)-1) (Scheme 1) [9]. A prerequisite for the synthesis was the development of a new

• silico for non-peptide malignant brain tumor (MBT) antagonist activity, showing hits on three MBT-containing proteins [35]. Although Carex brevicollis DC has been observed to have a teratogenic effect on animals [1][36], which could be linked with the presence of the two mentioned β-carboline alkaloids

Recent advances in controllable/divergent synthesis

• Jilei Cao,
• Leiyang Bai and
• Xuefeng Jiang

Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73

• carbon monoxide were used as starting materials, and two natural product frameworks of phenanthridone and acridone alkaloids could be selectively obtained by controlling ligands. The reaction of o-iodoaniline with in situ-generated arynes under CO atmosphere under ligand-free conditions selectively

• protoberberine and protonitidine alkaloids are characterized by an isoquinoline ring skeleton. An analysis of their molecular structures revealed that the two alkaloids share a basic structure, differing only in the junction of the B-ring. In 2021, Liu and Jiang designed new pyridyne precursors, which underwent

• , leading to the synthesis of differently substituted protonitidine alkaloids and protoberberine alkaloids (Scheme 25) [56]. Conclusion Developing streamlined and versatile approaches for the rapid assembly of structurally diverse organic molecules represents a pivotal challenge in organic synthesis

Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

Streamlined modular synthesis of saframycin substructure via copper-catalyzed three-component assembly and gold-promoted 6-endo cyclization

• Asahi Kanno,
• Ryo Tanifuji,
• Satoshi Yoshida,
• Sota Sato,
• Saori Maki-Yonekura,
• Kiyofumi Takaba,
• Jungmin Kang,
• Kensuke Tono,
• Koji Yonekura and
• Hiroki Oguri

Beilstein J. Org. Chem. 2025, 21, 226–233, doi:10.3762/bjoc.21.14

• coupling with gold(I)-mediated 6-endo cyclization streamlines the rapid and modular assembly of the substructure of bis-tetrahydroisoquinoline (THIQ) alkaloids. The design of the key synthetic intermediate bearing a 2,3-diaminobenzofuran moiety allows both gold(I)-mediated regiocontrolled 6-endo

• involvement of a fluorescent intermediate in the cascade synthetic process. Keywords: cascade reactions; copper-catalyzed three-component coupling; gold-mediated 6-endo hydroamination; tandem cyclizations; tetrahydroisoquinoline alkaloids; Introduction The bis-tetrahydroisoquinoline (THIQ) alkaloid family

• a fluorescent intermediate 18, and subsequent ring opening allowed a streamlined one-pot access to the substructure of THIQ alkaloids 14 in a good yield of 60% from 11. The structure of the resulting 14 was elucidated through comprehensive two-dimensional NMR spectroscopy, complemented by NOE

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

Non-covalent organocatalyzed enantioselective cyclization reactions of α,β-unsaturated imines

• Sergio Torres-Oya and
• Mercedes Zurro

Beilstein J. Org. Chem. 2024, 20, 3221–3255, doi:10.3762/bjoc.20.268

• -diamino derivative 37 in a good yield and an excellent enantioselectivity. Brønsted bases Cinchona alkaloids have been established as highly efficient chiral organocatalysts, capable to engage in a wide array of enantioselective processes [35]. They possess a unique structure. Firstly, the bulky

• catalysts are synthesized by joining together two fragments of cinchona alkaloids. In this manner, it is possible to obtain a symmetric catalyst, which can engage in hydrogen bonding interactions and deprotonation processes. Although they were originally used for Sharpless dihydroxylation, they have been

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

• belonging to the order Verongiida are known to contain a diverse array of bromotyrosine alkaloids with a broad spectrum of biological activities [1]. To date, approximately 500 bromotyrosine alkaloids have been isolated from sponges, with those featuring the 8,10-dibromo-9-methoxy-1,6-dioxa-2-azaspiro[4.6

• ]undeca-2,7,9-trien-4-ol moiety classified as psammaplysin derivatives. About 50 psammaplysin derivatives have been identified so far [2][3]. Among bromotyrosine alkaloids, the psammaplysin derivatives are particularly intriguing due to their structural complexity and biological activities. Psammaplysin

• derivatives exhibit a range of bioactivities, including antibacterial, anticancer, antimalarial, and antiviral effects. Since the discovery of the first psammaplysin derivative, psammaplysin A [4][5], these alkaloids have been recognized as challenging targets for total synthesis. The absolute configuration

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

• contained mixtures of polyamine-type alkaloids, which were combined for further isolation work. The following describes the purification of these fractions. Fractions 34–35 (5.0 mg) were purified by semipreparative phenyl RP-HPLC using isocratic conditions of 70% H2O (0.1% TFA)/30% MeOH (0.1% TFA) for the

Multicomponent reactions driving the discovery and optimization of agents targeting central nervous system pathologies

• Lucía Campos-Prieto,
• Aitor García-Rey,
• Eddy Sotelo and
• Ana Mallo-Abreu

Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261

• , inspired by natural alkaloids such as deoxyvasicinone and evodiamine with promising inhibition of ChEs and antioxidant and neuroprotective effects against glutamate-induced OS in HT-22 cells [41]. In 2016, Dgachi et al. [42] applied a Knoevenagel-based multicomponent approach to further explore the

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

• bioinformatic analysis. Their updated PRISM 4 pipeline outperformed antiSMASH5 and was able to predict the chemical structures of a wide variety of secondary metabolites [90]. Notably, the repertoire of PRISM 4 spans beyond NRPs and PKs and includes alkaloids, terpenoids, aminoglycosides, nucleosides, etc

• . Structure prediction of natural products other than NRPs and PKs has historically progressed slower. However, it was not due to a lack of data. Indeed, terpenoids and alkaloids are the two largest families of natural products in plants and also represent a sizable minority in microorganisms. The lagging

• information that are available for terpenoids and alkaloids biosynthesis. Data standardization (albeit a tedious and labor-intensive task) may be the final roadblock between AI and generalizable chemical structure metagenomics [91]. Conclusion and Outlook Microorganisms produce specialized metabolites to

gem-Difluorovinyl and trifluorovinyl Michael acceptors in the synthesis of α,β-unsaturated fluorinated and nonfluorinated amides

• Monika Bilska-Markowska,
• Marcin Kaźmierczak,
• Wojciech Jankowski and
• Marcin Hoffmann

Beilstein J. Org. Chem. 2024, 20, 2946–2953, doi:10.3762/bjoc.20.247

• of 1-fluorobis(phenylsulfonyl)methane (FBSM) to α,β-unsaturated ketones with cinchona alkaloids [9]. Fluorinated Michael acceptors usually contain one fluorine atom or a trifluoromethyl group in the structure [10][11][12]. There are also known examples of gem-difluoroalkenes being used as Michael

Synthesis of spiroindolenines through a one-pot multistep process mediated by visible light

• Francesco Gambuti,
• Jacopo Pizzorno,
• Chiara Lambruschini,
• Renata Riva and
• Lisa Moni

Beilstein J. Org. Chem. 2024, 20, 2722–2731, doi:10.3762/bjoc.20.230

• indole alkaloids. Here, we develop a novel approach for the one-pot multistep synthesis of different spiro[indole-isoquinolines]. The protocol proposed involves the visible light mediated oxidation of N-aryl tertiary amines using bromochloroform with the generation of a reactive iminium species, which

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

• -synthesized and posttranslationally modified peptides, polyketides, alkaloids, aromatics, and terpenoids. This generation of young investigators will continue to shape the field of natural products for years to come. We pass on our greatest thanks to all the contributors to this special thematic issue. We

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

• Alfiya R. Gimadieva,
• Yuliya Z. Khazimullina,
• Aigiza A. Gilimkhanova and
• Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

• , including drugs and alkaloids [8]. Several drugs are known to contain the 2-pyridone structure, such as the cardiotonic drugs milrinone (Figure 1c) and amrinone (Figure 1d) [9][10], as well as the antibiotic pilicide (Figure 1e) [11][12]. As described in [13] during preliminary experiments, it was

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

• investigated whether this protocol could be adapted to other lactams, allowing for a practical synthesis of bicyclic structures. The resulting bicyclic lactam substrate could serve as a foundation to access pyrroloisoquinoline alkaloids [50][51]. The model substrate 14 was synthesized in a two-step process

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• as a key methodology in the synthesis of alkaloids and natural products with 4-, 5- and 6-membered cyclic amine motifs. Initially reliant on stoichiometric reagents, synthetic chemists predominantly used N-substituted chiral imines, organometallic chiral reagents and achiral reagents with an

• ; rearrangement; Introduction Nitrogen-containing organic compounds (sometimes referred to as alkaloids due to their basic properties) are of critical importance in medicinal chemistry because of their unique binding properties to biomolecules [1]. Out of 55 drug candidates, approved by the FDA in 2023, 28 (51

• %) are nitrogen-containing organic compounds, with many featuring amino groups adjacent to a stereogenic centre. Some reports suggest that 75% of all FDA-approved compounds are alkaloids [2]. The industrial production of amines on a million-ton scale underscores the significance of methods for their

O,S,Se-containing Biginelli products based on cyclic β-ketosulfone and their postfunctionalization

• Kateryna V. Dil and
• Vitalii A. Palchykov

Beilstein J. Org. Chem. 2024, 20, 2143–2151, doi:10.3762/bjoc.20.184

• organic and medicinal chemists. DHPMs are found in a variety of marine-sourced alkaloids, which are essential for creating biologically active natural products [10]. Some of the DHPM derivatives are also known as functional polymers, adhesives, and fabric dyes [8][12]. In recent decades, the scope of the

Novel oxidative routes to N-arylpyridoindazolium salts

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

Beilstein J. Org. Chem. 2024, 20, 1906–1913, doi:10.3762/bjoc.20.166

• popular structural motif of many biologically active alkaloids and other molecules of therapeutic interest [1][2][3][4]. Polycyclic N-heteroaromatics also often exhibit intercalating properties [5][6][7][8][9]. Pyridoindazolium salts can be considered as one of the typical representatives of polyfused N

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

• -aminoimidazole moiety can be found in different alkaloids isolated from sponges and exhibits useful bioactive properties. The methodology employed by the authors to assemble C4/C5-functionalized 2-aminoimidazoles 49 exploited a Mannich condensation followed by an iodoxybenzoic acid (IBX) and N-iodophthalimide

Harnessing unprotected deactivated amines and arylglyoxals in the Ugi reaction for the synthesis of fused complex nitrogen heterocycles

• Javier Gómez-Ayuso,
• Pablo Pertejo,
• Tomás Hermosilla,
• Israel Carreira-Barral,
• Roberto Quesada and
• María García-Valverde

Beilstein J. Org. Chem. 2024, 20, 1758–1766, doi:10.3762/bjoc.20.154

• piperazinoquinazoline derivatives, a core found in fungal metabolites [25][26], systems with promising antitumour activity [27], as well as dipyrrolopiperazinone derivatives, substructure found in some alkaloids such as dibromophakellin or the palau’amine [28], which possess immunosuppressive and cytotoxic properties

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations

• Ryo Tanifuji and
• Hiroki Oguri

Beilstein J. Org. Chem. 2024, 20, 1693–1712, doi:10.3762/bjoc.20.151

• families, known as bistetrahydroisoquinoline (THIQ) alkaloids, share a highly functionalized pentacyclic scaffold with different aromatic ring oxidation states and sidechain structures [90][91][92][93]. The biosynthetic mechanism of 5 has been extensively studied by gene disruption and reconstruction of in

Polymer degrading marine Microbulbifer bacteria: an un(der)utilized source of chemical and biocatalytic novelty

• Weimao Zhong and
• Vinayak Agarwal

Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146

• classes of natural products isolated from Microbulbifer to date include alkaloids [15], fatty acid and polyketides [16][17], and non-ribosomally synthesized peptides [3][4][7]. These findings validate the potential for secondary metabolite discovery from Microbulbifer genus. This review will cover the

• from this bacterium by comparison of their 1H NMR and MS data with those reported in literature (Figure 7). Alkaloids Three new alkanoyl imidazoles 21–23 (Figure 8) were isolated from a culture extract of a Microbulbifer bacterium isolated from a scleractinian coral [15]. Their structures were

• of 32 natural products, including NRPSs, PKS, parabens, and alkaloids, have been isolated and identified from Microbulbifer bacteria. Based on the growing genomic data, it is unquestionable that the Microbulbifer genus is an untapped resource for natural products. The number of molecules described