Sustainable manganese catalysis for late-stage C–H functionalization of bioactive structural motifs

• Jongwoo Son

Beilstein J. Org. Chem. 2021, 17, 1733–1751, doi:10.3762/bjoc.17.122

• process facilitated the fluorination of sclareolide (1) and complex steroid 3. Sclareolide (1) is a naturally available terpenoid with antifungal and anticancer activities [23]. Under the optimized reaction conditions, sclareolide (1) is fluorinated at the C2 and C3 positions in 42% (see 2a) and 16% yield

• ® (antiplatelet), Gleevec® (anticancer), and augmentin (antibiotic), also contain the benzylic amine motif. Therefore, C–H amination is synthetically important for the diversification of biologically active molecules. Transition metal catalysis has set the stage for C–H amination processes in organic syntheses

• constitute an important structural modality in small-molecule drugs, such as levonorgestrel (birth control drug), efavirenz (HIV/AIDS treatment), and erlotinib (anticancer). Although step-economical C–H alkynylations have been investigated with 4d and 5d transition metals, 3d metal-catalyzed late-stage C–H

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

• Nikita Brodyagin,
• Martins Katkevics,
• Venubabu Kotikam,
• Christopher A. Ryan and
• Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

• Pezhman Shiri,
• Ali Mohammad Amani and
• Thomas Mayer-Gall

Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114

• screened for the synthesis of these rings [16][17]. Notably, triazole rings exhibit various medicinal applications, such as usages as anticancer [18] anti-HIV [19], antimalarial [20], antiplasmodial [21], and antibacterial agents [1][22]. Some significant triazole derivatives in this context are shown in

Iodine-catalyzed electrophilic substitution of indoles: Synthesis of (un)symmetrical diindolylmethanes with a quaternary carbon center

• Thanigaimalai Pillaiyar,
• Masoud Sedaghati,
• Andhika B. Mahardhika,
• Lukas L. Wendt and
• Christa E. Müller

Beilstein J. Org. Chem. 2021, 17, 1464–1475, doi:10.3762/bjoc.17.102

• biological activities (Figure 1) [10]. Unsubstituted DIM (I), for example, exhibits antimicrobial [5], anticancer [11][12][13], and anti-inflammatory effects (Figure 1) [14]. There is preclinical evidence for activity against several types of cancer [15], and DIM has been clinically evaluated for the

• treatment of prostate cancer [16] and showed promise for the treatment of cervical dysplasia [17]. The related trisindoline (II) was reported to possess antibiotic activity [18], while DIM derivatives III and IV also showed anticancer activities (Figure 1). Owing to their exciting biological activities, DIM

Synthesis of 1-indolyl-3,5,8-substituted γ-carbolines: one-pot solvent-free protocol and biological evaluation

• Premansh Dudhe,
• Mena Asha Krishnan,
• Kratika Yadav,
• Diptendu Roy,
• Krishnan Venkatasubbaiah,
• Biswarup Pathak and
• Venkatesh Chelvam

Beilstein J. Org. Chem. 2021, 17, 1453–1463, doi:10.3762/bjoc.17.101

• –c are shown to undergo a novel cascade imination-heterocylization in the presence of the organic base DIPEA to provide 1-indolyl-3,5,8-substituted γ-carbolines 3aa–ea in good yields. The γ-carbolines are fluorescent and exhibit anticancer activities against cervical, lung, breast, skin, and kidney

• single-photon counting (TCSPC) experiments. The average fluorescence lifetime of compound 3ac was found to be 8.35 ns and 4.73 ns in DMSO and DCM, respectively (Table 2, Figure 4). Biological evaluation of γ-carbolines as anticancer agents A panel of carboline derivatives 3ac, 3bc, 3ca, and 3ga, along

• -free method provides direct access to complex molecular structures in good yield from inexpensive substrates. The optical and biological evaluations carried out for representative γ-carbolines revealed promising photophysical and anticancer properties of the core framework for developing novel

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Synthesis of functionalized imidazo[4,5-e]thiazolo[3,2-b]triazines by condensation of imidazo[4,5-e]triazinethiones with DMAD or DEAD and rearrangement to imidazo[4,5-e]thiazolo[2,3-c]triazines

• Alexei N. Izmest’ev,
• Dmitry B. Vinogradov,
• Natalya G. Kolotyrkina,
• Angelina N. Kravchenko and
• Galina A. Gazieva

Beilstein J. Org. Chem. 2021, 17, 1141–1148, doi:10.3762/bjoc.17.87

• ], antituberculosis [2], anti-inflammatory [3][4], anticancer [5], antidiabetic [6][7], and antiviral activities [8]. A significant number of biologically active thiazolidines amount to their heteroannelated derivatives, namely, condensed thiazolo[3,2-a]pyrimidines [9] and thiazolo[3,2-b]-1,2,4-triazoles [10], as

• well as related thiazolo[3,2-b]-1,2,4-triazines and thiazolo[2,3-c]-1,2,4-triazines possessing antimicrobial, antidepressant, anti-HIV, and anticancer activities [10][11][12][13][14][15]. Modifications of the position 5 of the thiazolidine cycle often lead to an enhancement of the pharmacological

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

Synthetic accesses to biguanide compounds

• Oleksandr Grytsai,
• Cyril Ronco and
• Rachid Benhida

Beilstein J. Org. Chem. 2021, 17, 1001–1040, doi:10.3762/bjoc.17.82

• -driven research led to a large production of standard every-day drugs with antidiabetic, antiseptic, and even anticancer properties. Recently, biguanides have gained particularly increasing attention in several areas, such as drug design, coordination chemistry, and materials science [1]. In this context

• [1] such as antidiabetics, antimalaria, disinfectants, and antivirals. After a period of dormancy, the discovery of the anticancer activity of metformin has reignited a growing interest in biguanides. Indeed, in biological media, the biguanide group is highly prone to interaction with biomolecules

• alkylbiguanides with yields up to 97%, despite great variability in the case of alkylbiguanides (Scheme 8A) [24]. Recently, Zhou et al. reported similar conditions applied for the synthesis of anticancer biguanides [25]. The conditions chosen for the synthesis of a small library of pyrazole‐containing biguanide

Application of the Meerwein reaction of 1,4-benzoquinone to a metal-free synthesis of benzofuropyridine analogues

• Rashmi Singh,
• Tomas Horsten,
• Rashmi Prakash,
• Swapan Dey and
• Wim Dehaen

Beilstein J. Org. Chem. 2021, 17, 977–982, doi:10.3762/bjoc.17.79

• cancer cell lines [12][13]. Fluoroquinophenoxazines 2 have been used as telomerase inhibitors in anticancer research [14]. Furthermore, benzofuroisoindoles 3 were part of a kinase inhibitor study [15]. Photobiologically active psoralene (linear furocoumarin) dibenzofurans 1 and angular furanocoumarin

Beyond ribose and phosphate: Selected nucleic acid modifications for structure–function investigations and therapeutic applications

• Christopher Liczner,
• Kieran Duke,
• Gabrielle Juneau,
• Martin Egli and
• Christopher J. Wilds

Beilstein J. Org. Chem. 2021, 17, 908–931, doi:10.3762/bjoc.17.76

• acids (ANA) are analogs of RNA where the hydroxy group at C2' is inverted (Figure 1G). In fluoroarabino nucleic acids (FANA) this C2' hydroxy group is replaced by fluorine. Arabino- and fluoroarabino nucleosides have demonstrated anticancer and antiviral activities (as reviewed in [173]). β-ᴅ

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

• double bonds. Numerous natural compounds containing pyrans and benzopyrans (fused pyrans) are identified. Epicalyxin (45) is used as an anticancer agent against human HT-1080 fibrosarcoma and murine 26-L5 carcinoma. Laninamivir (46) is a pyran-based drug used as a neuraminidase inhibitor and zanamivir

• (47) for prevention of influenza A and B. β-Lapachone (48) shows diverse biological activities like anticancer, antibacterial and anti-inflammatory activities [53]. Benzopyrans and naphthopyrans represent a class of fused pyrans that has been studied for antimicrobial effects (49 and 50, Figure 4) [54

• approach delivered the desired product in 62% yield after 6 h which reveals the efficiency of microwaves in increasing the yield and reducing the reaction time. The studies for the anticancer activity of the synthesized molecules revealed them to be more potent than the standard doxorubicin against AGS

Synthesis of dibenzosuberenone-based novel polycyclic π-conjugated dihydropyridazines, pyridazines and pyrroles

• Ramazan Koçak and
• Arif Daştan

Beilstein J. Org. Chem. 2021, 17, 719–729, doi:10.3762/bjoc.17.61

• (pyridazomycin, pyridazocidin, and azamerone (Figure 1)) [23][24][25], numerous pyridazine derivatives have been synthesized and used in a wide variety of biochemical and physicochemical applications. Examples of these applications are as drug ingredients [26][27][28][29][30][31]; for their analgesic, anticancer

Effective microwave-assisted approach to 1,2,3-triazolobenzodiazepinones via tandem Ugi reaction/catalyst-free intramolecular azide–alkyne cycloaddition

• Maryna O. Mazur,
• Oleksii S. Zhelavskyi,
• Eugene M. Zviagin,
• Svitlana V. Shishkina,
• Vladimir I. Musatov,
• Maksim A. Kolosov,
• Elena H. Shvets,
• Anna Yu. Andryushchenko and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2021, 17, 678–687, doi:10.3762/bjoc.17.57

• high anticonvulsant activity after tests in silico and in vivо [7]. Moreover, compounds C and D reveal high activity as casein kinase 2 (CK2) inhibitor and high antitumor activity which makes compounds to be promising anticancer drugs [8]. There are quite a few methods for the synthesis of the

[2 + 1] Cycloaddition reactions of fullerene C₆₀ based on diazo compounds

• Yuliya N. Biglova

Beilstein J. Org. Chem. 2021, 17, 630–670, doi:10.3762/bjoc.17.55

• ]. Fullerene-containing compounds with antiviral (various forms of influenza, herpes, HIV) [28][29][30], antibacterial [31][32][33], and anticancer activity [34][35] have been found among them. An important approach in this area involves the synthesis of complex- and covalent-bound fullerene derivatives with

• first gave ester 181 and then acid 182 (Scheme 31), the sodium and potassium salts of which are well soluble in water. The compound has antiviral and anticancer activity as well as pronounced antioxidant properties combined with low toxicity. Diarylmethanofullerene 183 was synthesized according to

Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

Breakdown of 3-(allylsulfonio)propanoates in bacteria from the Roseobacter group yields garlic oil constituents

• Anuj Kumar Chhalodia and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 569–580, doi:10.3762/bjoc.17.51

• antibacterial, antifungal, antioxidant, anti-inflammatory, and anticancer effects [4]. Later on, also heterocyclic compounds including 2-vinyl-4H-1,3-dithiine (6) and 3-vinyl-3,4-dihydro-1,2-dithiine (7) were discovered [5]. The formation of these volatile sulfur compounds starts from alliin (9) [6], a non

Amino- and polyaminophthalazin-1(2H)-ones: synthesis, coordination properties, and biological activity

• Zbigniew Malinowski,
• Emilia Fornal,
• Agata Sumara,
• Renata Kontek,
• Karol Bukowski,
• Beata Pasternak,
• Dariusz Sroczyński,
• Joachim Kusz,
• Magdalena Małecka and
• Monika Nowak

Beilstein J. Org. Chem. 2021, 17, 558–568, doi:10.3762/bjoc.17.50

• -929 cell line, proved that some amino derivatives of phthalazinone show interesting anticancer activities. The detailed synthesis, spectroscopic data, and biological assays are reported. Keywords: amination; complexes; cytotoxicity; Pd cross-coupling; phthalazinone; Introduction Phthalazine and its

• ][14] and PDE-10 [15] for a potential use in the treatment of chronic pain and neurodegenerative or psychiatric disorders. Some of these derivatives are known to possess anti-inflammatory (p38 MAP kinase inhibitors, Figure 1) [16], cardiotonic [17], and anticancer (Aurora-A kinase inhibitors

• anticancer drug vatalanib [26][27][28] (Figure 1). On the other hand, aminophthalazinones can be prospective candidates as N- and O-donor ligands to form complexes with biological significant metal ions, such as copper or zinc [29]. Recently, we have demonstrated a strategy for the synthesis of phthalazinone

Synthesis and physicochemical evaluation of fluorinated lipopeptide precursors of ligands for microbubble targeting

• Masayori Hagimori,
• Estefanía E. Mendoza-Ortega and
• Marie Pierre Krafft

Beilstein J. Org. Chem. 2021, 17, 511–518, doi:10.3762/bjoc.17.45

• serine–glycine (SG)n segments rather than classical poly(oxyethylene) linkers between the lipid polar head and a targeting ligand were proposed for the liposome-mediated, selective delivery of anticancer drugs. Here, we report the synthesis of perfluoroalkylated lipopeptides (F-lipopeptides) bearing two

• (lipopeptides) have been used as the amphiphilic components of drug delivery systems with anticancer properties, such as the tripeptide Arg–Gly–Asp (RGD) that binds to integrin αvβ3, which is expressed on endothelial cells of various malignant tumors [15][19][20][21][22]. Other lipopeptides display cell

Deoxygenative C2-heteroarylation of quinoline N-oxides: facile access to α-triazolylquinolines

• Geetanjali S. Sontakke,
• Rahul K. Shukla and
• Chandra M. R. Volla

Beilstein J. Org. Chem. 2021, 17, 485–493, doi:10.3762/bjoc.17.42

• natural products [1][2][3][4], agrochemicals and pharmaceuticals having potent biological activities, such as antimalarial, antibacterial and anticancer activities [5][6][7][8][9][10][11]. Due to their wide range of applications, selective functionalization of quinolines at various positions has gained

1,2,3-Triazoles as leaving groups: S_NAr reactions of 2,6-bistriazolylpurines with O- and C-nucleophiles

• Dace Cīrule,
• Irina Novosjolova,
• Ērika Bizdēna and
• Māris Turks

Beilstein J. Org. Chem. 2021, 17, 410–419, doi:10.3762/bjoc.17.37

• ][3][4][5][6]. They are often used as antiviral, anticancer and antibacterial agents. Such intensive medicinal chemistry applications demand for constant development of novel synthetic methodologies. Frequently, the purine structure is modified in SNAr reactions with N- [7][8][9][10][11] and S

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• stereoselective methods for the synthesis and transformations of cyclopropane derivatives. These investigations gained a significant interest, because cyclopropane and cyclopropene fragments are present in the structures of many biologically active substances, such as antibiotics, anticancer, and antimycotic

Selective synthesis of α-organylthio esters and α-organylthio ketones from β-keto esters and sodium S-organyl sulfurothioates under basic conditions

• Jean C. Kazmierczak,
• Roberta Cargnelutti,
• Thiago Barcellos,
• Claudio C. Silveira and
• Ricardo F. Schumacher

Beilstein J. Org. Chem. 2021, 17, 234–244, doi:10.3762/bjoc.17.24

• in several worldwide-consumed drugs and agrochemicals [32][33][34][35][36][37][38]. Figure 1 shows examples of these pharmacologically active compounds, such as the antibiotics retapamulin and cefmetazole [32][33][34][35], the anticancer agent RETRA [36], and agrochemicals with pesticidal (malathion

Au(III) complexes with tetradentate-cyclam-based ligands

• Ann Christin Reiersølmoen,
• Thomas N. Solvi and
• Anne Fiksdahl

Beilstein J. Org. Chem. 2021, 17, 186–192, doi:10.3762/bjoc.17.18

• ][20][21]. Simple [Au(III)–cyclam] complexes have been investigated for various biological properties [22][23][24][25][26][27][28][29]. Particularly, studies have focused on their potential in vitro anticancer properties [24][26][29], the activity against a falciparum strain [22], the in vitro DNA