Synthesis of heterocycles based on azomethine ylides from α-amino acids (or amines) and carbonyl compounds

• Ekaterina V. Berezhnaya,
• Alexander I. Ponyaev,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2026, 22, 705–741, doi:10.3762/bjoc.22.55

• iminoesters 34 derived from natural compounds or currently available synthetic drugs (Scheme 17). Iminoesters containing molecules of cholesterol, androsterone, indomethacin, pitavastatin, menthol, as well as fructose and glucose, were introduced into the reaction. In [55], copper(I)-catalyzed asymmetric 1,3

Anti-invasive and cytotoxic evaluation of a (+)-pinoresinol-based semisynthetic library against glioblastoma

• Chen Zhang,
• Kah Yean Lum,
• Jonathan M. White,
• Paul I. Forster,
• Nicholas Booth,
• Sunita A. Ramesh and
• Rohan A. Davis

Beilstein J. Org. Chem. 2026, 22, 691–704, doi:10.3762/bjoc.22.54

• approved by the FDA are derived from natural products, their derivatives, or synthetic mimetics inspired by natural compounds [5]. The traditional knowledge of native plants for medicinal purposes is invaluable, and there are ongoing investigations by many research groups from around the world that aim to

Melifoliox B, a novel phloroglucin derivative isolated from Melicope barbigera (Rutaceae) and synthesis of new oxidation products from melifoliones A and B

• Horst Weber,
• Kim-Thao Tran-Cong,
• Bernhard Mayer,
• Guido J. Reiss,
• Iryna S. Konovalova,
• Marc S. Appelhans,
• Kenneth R. Wood and
• Claus M. Passreiter

Beilstein J. Org. Chem. 2026, 22, 535–546, doi:10.3762/bjoc.22.39

• been described in the literature. Keywords: Melicope barbigera; Melifoliones A and B; new heterocyclic ring systems; new natural compounds; para-quinols; phenol oxidation; Introduction The genus Melicope is a member of the Rutaceae (Citrus family) and contains more than 200 species distributed in the

Competitive cyclization of ethyl trifluoroacetoacetate and methyl ketones with 1,3-diamino-2-propanol into hydrogenated oxazolo- and pyrimido-condensed pyridones

• Svetlana O. Kushch,
• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess,
• Pavel A. Slepukhin,
• Alexandrina S. Volobueva,
• Vladimir V. Zarubaev and
• Victor I. Saloutin

Beilstein J. Org. Chem. 2025, 21, 2716–2729, doi:10.3762/bjoc.21.209

• the one hand, owing to the fact that the pyridine framework is widespread among natural compounds [40][41], and, on the other hand, because of the unique properties of fluorine [42][43][44][45]. In this work, 1,3-diaminopropan-2-ol (3) has for the first time been introduced into the reaction of ethyl

Recent advancements in the synthesis of Veratrum alkaloids

• Morwenna Mögel,
• David Berger and
• Philipp Heretsch

Beilstein J. Org. Chem. 2025, 21, 2657–2693, doi:10.3762/bjoc.21.206

• cyclopamine (6) proceeded through veratramine (13), before interconverting veratramine into cyclopamine. Therefore, the Zhu/Gao groups strategy provides access to both natural compounds; the synthesis will later also be discussed in the veratramine paragraph. For the synthesis of the left-hand fragment, the

Thiazolidinones: novel insights from microwave synthesis, computational studies, and potentially bioactive hybrids

• Luan A. Martinho,
• Victor H. J. G. Praciano,
• Guilherme D. R. Matos,
• Claudia C. Gatto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203

• scaffolds for several synthetic or natural compounds [5]. Five-membered heterocycles include the thiazolidinone nucleus, characterized by two heteroatoms and a carbonyl group on the fourth carbon, as seen in compounds like rhodanine and thiazolidine-2,4-dione derivatives (Figure 1). These privileged

Transformation of the cyclohexane ring to the cyclopentane fragment of biologically active compounds

• Natalya Akhmetdinova,
• Ilgiz Biktagirov and
• Liliya Kh. Faizullina

Beilstein J. Org. Chem. 2025, 21, 2416–2446, doi:10.3762/bjoc.21.185

• modifications of the carbohydrate residue in compound 30 resulted in 8-epi-loganin (32) [24][25]. Thus, as a result of intriguing transformations based on Diels–Alder adducts of LG with butadiene and piperylene, cyclopentane derivatives were obtained, which are promising for the synthesis of natural compounds

• and 51 showed high cytotoxic activity (IC50 1.38–15.91 μM). 2 Rearrangements with 1,2-carbon migration Rearrangements with 1,2-carbon migration are widely used in the synthesis of natural compounds [37]. These include benzilic acid and semipinacol-type rearrangements, reactions promoted by thallium

The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions

• Ayhan Yıldırım and
• Mustafa Göker

Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184

• different sources [4][5]. In order to fulfil this requirement, a considerable number of green solvents of various classes have been developed for a range of applications, including the extraction of natural compounds [6][7][8][9], food analysis [10][11][12], pharmacology [13][14][15], and organic synthesis

• the time- and labor-intensive nature of traditional multistep synthesis strategies. For instance, this methodology has been demonstrated to be highly advantageous in the synthesis of numerous pharmaceutical compounds, biological probes, insecticides, alkaloids, and other intricate natural compounds

• series of studies were conducted on natural compounds selected for use as catalysts within the scope of this work. These studies revealed that there was no significant alteration to the ratio of diastereoisomers when the respective catalysts were utilized. In summary, methyl laurate is a solvent that has

Gold extraction at the molecular level using α- and β-cyclodextrins

• Susana Santos Braga

Beilstein J. Org. Chem. 2025, 21, 1116–1125, doi:10.3762/bjoc.21.89

• high selectivity. The present review is centered on the use of cyclodextrins, natural and biocompatible oligosaccharides that form upon microbial fermentation of starch. The method is environmentally safe because it resorts to natural compounds, posing as a promising alternative to the use of cyanides

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

• , Figure S1), confirming the acid functional group in the natural compounds. In support of these data, GC/IR analysis of Dm (Supporting Information File 1, Figure S2) showed strong carbonyl bands at 1741 cm−1 accompanied by two intermediate bands at 1198 cm−1 and 1177 cm−1, characteristic of ester valence

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

• the tolerability of a wide range of aldehydes, starting from one of the most used, benzaldehyde, passing through heteroaromatic and aliphatic structures with different substituents. In this context, some examples where the aldehyde functionality is incorporated into sugar derivatives, natural

• compounds or molecules derived from biomass have been recently published. Due to the relatively drastic conditions of the GBB reaction and the inherent lability of these structurally complex building blocks, often specific reaction conditions have been developed to successfully obtain the multicomponent

A facile three-component route to powerful 5-aryldeazaalloxazine photocatalysts

• Ivana Weisheitelová,
• Radek Cibulka,
• Marek Sikorski and
• Tetiana Pavlovska

Beilstein J. Org. Chem. 2024, 20, 1831–1838, doi:10.3762/bjoc.20.161

• of applications in medicinal chemistry, chemosensors, polymers and catalysis [1][2][3][4][5][6][7][8]. Among them, flavins (Fl) are essential redox-active natural compounds that act as enzyme cofactors in numerous biochemical processes [9]. Structurally related to flavins are isomeric alloxazines

Sustainable tandem acylation/Diels–Alder reaction toward versatile tricyclic epoxyisoindole-7-carboxylic acids in renewable green solvents

• Ayhan Yıldırım

Beilstein J. Org. Chem. 2024, 20, 1308–1319, doi:10.3762/bjoc.20.114

• Ayhan Yildirim Department of Chemistry, Bursa Uludağ University, Bursa 16059, Turkey 10.3762/bjoc.20.114 Abstract Tandem Diels–Alder reactions are often used for the straightforward formation of complex natural compounds and the fused polycyclic systems contained in their precursors. In the

• anhydride. This is a useful approach for the total synthesis of complex natural compounds, epoxyisoindole skeleton-based precursors for various polycyclic compounds, and bio-based homo- and copolymers [71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96][97

• reactions, which are a useful strategy for the preparation of many natural compounds and various organic intermediates, can be safely carried out under more environmentally friendly conditions. Experimental All reagents and solvents were purchased from Merck (Merck, Darmstadt, Germany), Sigma-Aldrich (St

A new analog of dihydroxybenzoic acid from Saccharopolyspora sp. KR21-0001

• Rattiya Janthanom,
• Yuta Kikuchi,
• Hiroki Kanto,
• Tomoyasu Hirose,
• Arisu Tahara,
• Takahiro Ishii,
• Arinthip Thamchaipenet and
• Yuki Inahashi

Beilstein J. Org. Chem. 2024, 20, 497–503, doi:10.3762/bjoc.20.44

• actinomycetes, with 70% from Streptomyces and the rest from rare actinomycetes (non-Streptomyces) [5]. Rare actinomycetes are defined as actinomycete strains with low isolation rates when compared with the isolation of Streptomyces [6]. Currently, the discovery of new natural compounds is focusing on rare

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• compounds. Keywords: amphiphiles; edelfosine; GAEL; glycerol lipids; glycolipids; ohmline; plasmalogen; Introduction Ether lipids (ELs) are natural compounds that feature a glycerol unit linked with an ether function to an alkyl (alkyl acyl ether lipid) or alkenyl (plasmalogen) lipid chain. For the

• acylation of lyso-PAF with a series of functionalized carboxylic acid was reported in a series of articles from the group of Salomon [98][99]. This group aimed to identify natural compounds that could be formed by the oxidation of ether lipids featuring a polyunsaturated acyl chain in sn-2 position. This

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• drug and natural compounds containing functionalized ether α-C(sp3)–H bonds CDC reactions can be applied. This review mainly focuses on the CDC reactions of ether oxygen α-C(sp3)–H bonds via non-noble metal-catalysis (Scheme 1d). Review Non-noble metal-catalyzed CDC reactions involving ether α-C(sp3)–H

Acetaldehyde in the Enders triple cascade reaction via acetaldehyde dimethyl acetal

• Alessandro Brusa,
• Debora Iapadre,
• Maria Edith Casacchia,
• Alessio Carioscia,
• Giuliana Giorgianni,
• Giandomenico Magagnano,
• Fabio Pesciaioli and
• Armando Carlone

Beilstein J. Org. Chem. 2023, 19, 1243–1250, doi:10.3762/bjoc.19.92

• tool for achieving molecular complexity. Their synthetic potential has been demonstrated by their application in the total synthesis of complex natural compounds [2][4][9][10][11][12]. A remarkable example of an amino-catalyzed cascade process was reported by Enders [11], a three-component cascade

Synthesis of tetrahydrofuro[3,2-c]pyridines via Pictet–Spengler reaction

• Elena Y. Mendogralo and
• Maxim G. Uchuskin

Beilstein J. Org. Chem. 2023, 19, 991–997, doi:10.3762/bjoc.19.74

• ]pyridines represent an important class of heterocyclic compounds, which skeleton is the key frame of many bioactive and natural compounds. For example, tetrahydrofuro[3,2-c]pyridine A demonstrates excellent in vitro JAK2 inhibitory activity superior to tofacitinib (Figure 1) [1]. Furan B is a potent κ

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

•  56B) [103]. These complex natural compounds exhibit strong pharmacological activities like anti-inflammatory, antituberculosis, analgesic properties, etc. The key reaction steps included a highly stereoselective gold-catalyzed or thermally activated Cope rearrangement and a gold-catalyzed 6-endo-dig

Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis

• Nicoleta G. Hădărugă,
• Gabriela Popescu,
• Dina Gligor (Pane),
• Cristina L. Mitroi,
• Sorin M. Stanciu and
• Daniel Ioan Hădărugă

Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30

• Mihai I” from Timişoara, Calea Aradului 119, 300645 Timişoara, Romania Department of Economy and Company Financing, University of Life Sciences “King Mihai I” from Timişoara, Calea Aradului 119, 300645 Timişoara, Romania Department of Applied Chemistry, Organic and Natural Compounds Engineering

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

• process, two major families of natural compounds are formed, namely the aporphine and the morphinandienone alkaloids. Mimicking the selectivity of the natural process in laboratory setups commonly proves tricky, producing an irreproducible yield of isomers for both classes. Recently, Felpin’s group

• the total synthesis of (−)-psychotriasine (202), (−)-calycanthidine (203), and (−)-chimonanthine (204). Synthesis of structurally diverse lignans (Zhu, 2022) [103]: Lignans are structurally diverse natural compounds generated biosynthetically by the oxidative dimerization of phenylpropanoids [104

Functionalization of imidazole N-oxide: a recent discovery in organic transformations

• Koustav Singha,
• Imran Habib and
• Mossaraf Hossain

Beilstein J. Org. Chem. 2022, 18, 1575–1588, doi:10.3762/bjoc.18.168

• reaction; Introduction Imidazole is one of the best-known heterocyclic compounds. Derivatives of imidazole are powerful molecules taking part in numerous biochemical processes and exhibiting distinctive biological activities [1][2]. The imidazole motif can be seen in several natural compounds like

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• ][10]. In addition, these 2-oxopyrroles are structural subunits of various bioactive natural compounds and synthetic drugs. For example, codinaeopsin has been isolated from a fungal extract of a tree called Vochysia guatemalensis which shows antimalarial activity [11]. Pyrrocidine A was isolated from

• also important substructures in a variety of non-natural compounds and their pharmacological effects against bacteria [13][14][15][16], inflammation [17][18], viruses [19], radical [20], and cancer [21][22][23][24][25][26] have been proven. It is undoubtedly true that heterocyclic compounds containing

• [47]: with Qtun, ΔG#, ωi are tunneling transmission coefficient, Gibbs free energy values, and imaginary frequencies of transition states, respectively. Structure of naturally occurring and synthetic 2-pyrrolidone derivatives. Structure of natural compounds containing a 1,5-dihydro-2H-pyrrol-2-one

Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

• Alexander S. Filatov,
• Olesya V. Khoroshilova,
• Anna G. Larina,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2022, 18, 769–780, doi:10.3762/bjoc.18.77

• found in natural compounds [9][10][11]. It is used in pharmaceuticals [12][13][14][15] and key intermediates [16][17]. Compounds containing a 3-azabicyclo[3.1.0]hexane moiety are antagonists of morphine-induced antinociception [18], histone deacetylase inhibitors [13], and opioid receptor antagonists

The PIFA-initiated oxidative cyclization of 2-(3-butenyl)quinazolin-4(3H)-ones – an efficient approach to 1-(hydroxymethyl)-2,3-dihydropyrrolo[1,2-a]quinazolin-5(1H)-ones

• Alla I. Vaskevych,
• Nataliia O. Savinchuk,
• Ruslan I. Vaskevych,
• Eduard B. Rusanov,
• Oleksandr O. Grygorenko and
• Mykhailo V. Vovk

Beilstein J. Org. Chem. 2021, 17, 2787–2794, doi:10.3762/bjoc.17.189

• compounds to provide novel, sp3-enriched scaffolds with increased propensity to generate potent lead structures with favorable physicochemical properties [1][2][3][4]. In light of this, synthesis of compounds that are close analogs of natural compounds is an important task for the synthetic organic