Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives

• Yi Liu,
• Puying Luo,
• Yang Fu,
• Tianxin Hao,
• Xuan Liu,
• Qiuping Ding and
• Yiyuan Peng

Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163

• organic molecules can efficiently modify the physical, chemical, and biological properties of the compounds. A trifluoromethyl-substituted pyrrole unit is widely present in many natural compounds and pharmaceuticals with high biological activity. Based on our previous study on the construction of

Strategies for the synthesis of brevipolides

• Yudhi D. Kurniawan and
• A'liyatur Rosyidah

Beilstein J. Org. Chem. 2021, 17, 2399–2416, doi:10.3762/bjoc.17.157

• ], asthma and malaria (southern Sahara) [2][3], and to combat intestinal parasites (Bolivia) [5]. In addition, this plant has also been used as a natural pesticide, particularly in cereal conservations, and to repel mosquitoes (southern Sahara) [2][3]. Biological activity investigations of the plant extract

• ][12]. The biological activity data of brevipolides A–O (1–15) and their analogs from literature has been summarized in Tables 1–3. Table 1 presents the cytotoxicity data of compounds 1–15 and their analogs, if existing, against a range of cancer cell lines. A cytotoxicity study against Lu1 human lung

• correlation with biological activity. This analysis attributed two detected [M − H]− signals to dihydrobrevipolides C and F. Nevertheless, further structural identification was not performed. Conclusion The characteristic structural features of 5,6-dihydro-α-pyrone derivatives isolated from Hyptis brevipes

Synthesis and antimicrobial activity of 1H-1,2,3-triazole and carboxylate analogues of metronidazole

• Satya Kumar Avula,
• Syed Raza Shah,
• Khdija Al-Hosni,
• Muhammad U. Anwar,
• Rene Csuk,
• Biswanath Das and
• Ahmed Al-Harrasi

Beilstein J. Org. Chem. 2021, 17, 2377–2384, doi:10.3762/bjoc.17.154

• 1H-1,2,3-triazole moiety in the medicinal field. In addition, the above-mentioned activity of all the active compounds was reported for the first time for these derivatives. Structure of metronidazole (1). Chemical structures of some metronidazole derivatives with different biological activity

Phenolic constituents from twigs of Aleurites fordii and their biological activities

• Kyoung Jin Park,
• Won Se Suh,
• Da Hye Yoon,
• Chung Sub Kim,
• Sun Yeou Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2021, 17, 2329–2339, doi:10.3762/bjoc.17.151

• 13C NMR, COSY, HSQC, HMBC, and NOESY), HRMS, and chemical methods. The isolated compounds 1–19 were evaluated for their antineuroinflammatory and neuroprotective activities. In this paper, we report the isolation and structural elucidation of these phytochemicals and their biological activity. Results

Post-functionalization of drug-loaded nanoparticles prepared by polymerization-induced self-assembly (PISA) with mitochondria targeting ligands

• Janina-Miriam Noy,
• Fan Chen and
• Martina Stenzel

Beilstein J. Org. Chem. 2021, 17, 2302–2314, doi:10.3762/bjoc.17.148

• evaluate the changes in cellular uptake or the toxicity of the conjugated arsenic drug. Attachment of TPP onto the PISA particles however was found not to enhance the mitochondrial accumulation, but it did influence overall the biological activity of pMPC-based particles in 2D and 3D cultured sarcoma SW982

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

• correlation between chain length and biological activity, significant effort has been put to chemically synthesize β(1–3)-glucans with well-defined lengths. In contrast to β(1–4)-glucans (i.e., cellulose), β(1–3)-glucans with a DP up to 20 can be dissolved in water [112], simplifying the synthetic process

• controlled size and substitution pattern are highly desirable, because DP and FA affect the physicochemical properties of the COS [218][219]. A size-dependent immune recognition was verified in plant chitin receptors as well as in toll-like receptors (TLR2) [220]. Moreover, the PA can tune the biological

• activity, as demonstrated using partially acetylated COS obtained by enzymatic degradation of chitosan promoted by hydrolases [221]. Chemical degradation of chitin promoted by acid treatment [222][223][224][225][226][227][228] or using chitinases and chitosanases [229][230][231] generates mixtures of short

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• (dimethylamino)titanium [Ti(NMe2)4] and tetrabenzyltitanium [TiBn4], and it was observed that a better stereoselectivity was achieved by using the first catalyst while a better yield was obtained when the second catalyst was applied (Scheme 8B). Although the authors did not explore any possible biological

• activity of the obtained products, some compounds bearing an N-substituted cyclohexylamine moiety are known to present antidepressant and analgesic activities (e.g., compounds 19, 20, and 21, Scheme 8A) [75]. Further studies could reveal other notable biological activities, thus justifying the need to

Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus

• Jana M. Boysen,
• Nauman Saeed and
• Falk Hillmann

Beilstein J. Org. Chem. 2021, 17, 1814–1827, doi:10.3762/bjoc.17.124

• , temperature and aeration, are known to regulate gliotoxin biosynthesis [115][119][120]. The biological activity of ETP’s like gliotoxin is mediated by the active disulfide bridge that targets vulnerable thiols or catalyses oxidative burst formation via redox cycling [78]. In previous studies, these cytotoxic

• decatetraenedioic acid connected via an ester bond. There is also a methoxy group, an epoxide and a terpene derived aliphatic chain that contains another epoxide, linked to cyclohexane. These unstable di-epoxides are responsible for the biological activity of fumagillin, which targets the active site of the

Recent advances in the application of isoindigo derivatives in materials chemistry

• Andrei V. Bogdanov and
• Vladimir F. Mironov

Beilstein J. Org. Chem. 2021, 17, 1533–1564, doi:10.3762/bjoc.17.111

• , to date, the volume of publications on the study of the biological activity of isoindigo derivatives has been steadily decreasing. At the same time, the unique properties of the isoindigo structure (planarity, stability, a high degree of conjugation, and electron deficiency) began to attract more and

A straightforward conversion of 1,4-quinones into polycyclic pyrazoles via [3 + 2]-cycloaddition with fluorinated nitrile imines

• Greta Utecht-Jarzyńska,
• Karolina Nagła,
• Grzegorz Mlostoń,
• Heinz Heimgartner,
• Marcin Palusiak and
• Marcin Jasiński

Beilstein J. Org. Chem. 2021, 17, 1509–1517, doi:10.3762/bjoc.17.108

• considerable attention of other groups [18][19] and recently has been applied for the preparation of some π-extended pyrazole derivatives, which exhibited promising biological activity [20]. In a series of our recent publications, efficient syntheses of fluoromethylated five- and six-membered N,S-heterocycles

Substituted nitrogen-bridged diazocines

• Pascal Lentes,
• Jeremy Rudtke,
• Thomas Griebenow and
• Rainer Herges

Beilstein J. Org. Chem. 2021, 17, 1503–1508, doi:10.3762/bjoc.17.107

• . Moreover, the photoconversion yield for the E→Z isomerization is quantitative (within the detection limit of UV and NMR spectroscopy). A high efficiency in switching the biological activity off is important to avoid side effects of residual concentrations of the active form [13]. Water solubility and high

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

• broad range of substrates is tolerated and the reaction is suitable for large-scale preparation of the target compounds. The outlined methodology allows for the rapid generation of structurally diverse DIM derivatives to study structure–activity relationships, to optimize biological activity and other

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

• followed by their duplex formation studies against complimentary oligonucleotide strands had described a very selective zipper-interaction [35], whereas a relative stabilization was observed due to stacking of these additional nucleobases across the minor groove [31]. The biological activity of the acyclic

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

• catalysts in various organic reactions [1] such as the Ullmann coupling, Suzuki coupling, Suzuki–Miyaura coupling, and the Heck reaction. Aside from being useful synthetic agents, biguanides gained particular interest from the perspective of medicinal chemistry. For the first time, the biological activity

Synthesis of 10-O-aryl-substituted berberine derivatives by Chan–Evans–Lam coupling and investigation of their DNA-binding properties

• Peter Jonas Wickhorst,
• Mathilda Blachnik,
• Denisa Lagumdzija and
• Heiko Ihmels

Beilstein J. Org. Chem. 2021, 17, 991–1000, doi:10.3762/bjoc.17.81

• as fluorescent probe in bioanalytical chemistry [15][16]. Because of these attractive properties of this lead structure, numerous berberine derivatives have been synthesized in order to further improve the biological activity [17][18][19][20][21][22][23][24][25][26]. Among those derivatives

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

• -alkylated pyridones are valuable scaffolds offering biological activity such as immunomodulators, memory-enhancers and anticancer agents [109][110]. A direct approach to achieve N-alkylated pyridones are less explored and those available present limitations such as poor selectivity and yields, expensive

Synthetic reactions driven by electron-donor–acceptor (EDA) complexes

• Zhonglie Yang,
• Yutong Liu,
• Kun Cao,
• Xiaobin Zhang,
• Hezhong Jiang and
• Jiahong Li

Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67

• functional-group tolerance are provided by this approach, yielding multiple indole analogues with biological activity. In 2017, Liang and Bi [56] reported a visible-light-induced three-component cyclization of ethyl acetoacetate (23), perfluoroalkyl iodides 24, and guanidine hydrochloride (25) via a halogen

Total synthesis of pyrrolo[2,3-c]quinoline alkaloid: trigonoine B

• Takashi Nishiyama,
• Erina Hamada,
• Daishi Ishii,
• Yuuto Kihara,
• Nanase Choshi,
• Natsumi Nakanishi,
• Mari Murakami,
• Kimiko Taninaka,
• Noriyuki Hatae and
• Tominari Choshi

Beilstein J. Org. Chem. 2021, 17, 730–736, doi:10.3762/bjoc.17.62

• heterocyclic compounds by constructing fused pyridine ring systems based on a thermal electrocyclization of an azahexatriene moiety [14][15]. It has been hoped that the development of compounds with enhanced biological activity would be possible using these natural products and their derivatives [16][17][18

• the synthesis of various N-substituted 4-aminopyrroloquinolines. The investigation of the biological activity of trigonoine B and its derivatives is under evaluation. Natural products possessing the pyrrolo[2,3-c]quinoline skeleton. Total synthesis of marinoquinolines and the failure of the

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

• molecular frameworks in medicinal chemistry. Of these, 1,4-benzodiazepines fused with pyrazole or triazole cycles are the base for many drugs (Figure 1) [1]. The spectrum of their biological activity includes tranquilizing, muscular relaxant, anticonvulsant, and sedative effects [2]. The general application

• success in the treatment of CNS disorders [6]. Preliminary studies of the biological activity of other diversely substituted 1,2,3-triazolobenzodiazepines demonstrate their similar properties with all main categories of 1,2,4-triazolobenzodiazepine-based drugs [7]. For example, compound B demonstrated

• compounds was obtained. Currently, we are working on testing some library representatives for their biological activity. Benzodiazepine-based azolo-containing drugs. Novel potential 1,2,3-triazolobenziadiazepine drugs. Code legend for Ugi products 6 and molecular structure (X-ray analysis) of compound 6aaa

[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

• ], have already been discovered among functionalized fullerenes. Bearing in mind the fact that numerous fullerene derivatives with a wide range of biological activity have been synthesized to date, the idea of using functionalized fullerenes in the field of medical chemistry, especially for the treatment

• ideal partner for drug lipophilization by conjugation [37]. Highly efficient fullerene conjugates with chemotherapeutic agents have been synthesized and patented; moreover, the biological activity profile is often preserved, but in some cases it can also change since a molecular structure with a

• ], where the synthesis of N,N-(tetrachlorophthaloyl)dehydroabietylamine derivatives 198–201 from dehydroabietylamine substituted by fullerene in ring B was reported (Scheme 36). These compounds were obtained in a search for new derivatives of rosin amines with potential biological activity. Further, an

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

• acids, polysaccharides), which are "susceptible to degradation by biological activity by lowering of the molar masses of macromolecules". Therefore, in this situation, “chain cleavage” and “degradation” are used interchangeably. To avoid confusion, instead of “(bio)degradation”, in the present review

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

Synthetic strategies of phosphonodepsipeptides

• Jiaxi Xu

Beilstein J. Org. Chem. 2021, 17, 461–484, doi:10.3762/bjoc.17.41

• reacted with benzyl (R)-lactate ((R)-26b) or benzyl (R)-2-phenyllactate ((R)-26f). The optically active phosphonodepsidipeptides 28 were obtained after hydrogenolysis and tested for their biological activity (Scheme 5) [22]. The phosphonodepsidipeptides 31 were synthesized by the esterification of N-Cbz

Synthesis of legonmycins A and B, C(7a)-hydroxylated bacterial pyrrolizidines

• Wilfred J. M. Lewis,
• David M. Shaw and
• Jeremy Robertson

Beilstein J. Org. Chem. 2021, 17, 334–342, doi:10.3762/bjoc.17.31

• methyl groups in the bohemamines and NP25302 [24]. Our interest in this area originated in reports of significant biological activity for those bacterial pyrrolizidines for which such effects have been assessed. The clazamycins, jenamidine A, dibohemamines D–F, and quinohemamine are all reported to be