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

• protein–ligand binding properties as well as biological activities of small molecules, potentially leading to dramatic increases in potency, and thus has been widely explored in drug discovery [54][55][56]. Late-stage C–H methylation has recently been investigated using iron and cobalt catalysts as

Volatile emission and biosynthesis in endophytic fungi colonizing black poplar leaves

• Christin Walther,
• Pamela Baumann,
• Katrin Luck,
• Beate Rothe,
• Peter H. W. Biedermann,
• Jonathan Gershenzon,
• Tobias G. Köllner and
• Sybille B. Unsicker

Beilstein J. Org. Chem. 2021, 17, 1698–1711, doi:10.3762/bjoc.17.118

• work on this question is needed [63][75]. The volatiles found to be emitted from black poplar endophytic fungi in this study could have important biological activities. For instance, ethanol (17) and 2-phenylethanol (3) are known to have antifungal and phytotoxic activity and so could help the

2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli,
• Noureddine Chaaben,
• Kamel Alimi,
• Stefan Jopp and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

• appeared as a side product during the synthesis of anthracene [11] and became an abundant scaffold in medicinal chemistry [12][13][14]. Acridine derivatives have exhibited a range of biological activities [15][16][17][18][19][20] and have been particularly explored in chemotherapeutic protocols against

• ring, is another privileged scaffold which showed interesting biological activities [48][49][50][51][52][53][54]. As a typical example, 9-amino-1,2,3,4-tetrahydroacridine or tacrine was the first drug approved for the treatment of Alzheimer's disease [55][56][57]. Surprisingly, photophysical properties

Cascade intramolecular Prins/Friedel–Crafts cyclization for the synthesis of 4-aryltetralin-2-ols and 5-aryltetrahydro-5H-benzo[7]annulen-7-ols

• Jie Zheng,
• Shuyu Meng and
• Quanrui Wang

Beilstein J. Org. Chem. 2021, 17, 1481–1489, doi:10.3762/bjoc.17.104

• spectrum of biological activities [1][2][3]. Some representative compounds comprising this skeleton are illustrated in Figure 1. Cycloolivil (Figure 1, 2) [4], which is isolated from the stem bark of Olea europaea, has been recognized as inhibitor of cyclic AMP dependent phosphodiesterase, can act as a Ca2

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

• investigate these bioactive molecules and their targets in future studies. Diindolylmethanes and reported biological activities. Synthetic strategies toward trifluoromethylated unsymmetrical quaternary DIMs. Reactions performed to study the scope of the method. Gram-scale synthesis of unsymmetrical DIMs 3a

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

• shown promising biological activities in preclinical and clinical studies (Figure 1) [2][3][4][5][6]. The pyrimidine-γ-carboline alkaloid ingenine B (isolated from an Indonesian sponge) exhibits a pronounced cytotoxicity against a murine lymphoma cell line [7] and several isocanthine analogs are

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

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

• Orgánica (ISO), Universidad de Alicante, Apdo. 99, 03080 Alicante, Spain 10.3762/bjoc.17.86 Abstract The synthesis of nitrogen-containing heterocycles, including natural alkaloids and other compounds presenting different types of biological activities have proved to be successful employing chiral sulfinyl

• ][9][10][11] and other compounds that show different types of biological activities [12][13]. The way to achieve these transformations is by intramolecular cyclizations, involving the free primary amine, and appropriate reactive positions (those positions bearing a leaving group) in the electrophile

• influence on it the configuration of the sulfur atom of the sulfinyl unit. This methodology was applied to the asymmetric synthesis of (−)-CP-99,994 (128), the enantiomer of a promising clinical agent which displays a variety of biological activities, including neurogenic inflammation, pain transmission

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

• materials in organic synthesis for the preparation of nitrogen-containing heterocycles. Moreover, biguanides demonstrate a wide range of biological activities and some representatives are worldwide known such as metformin, the first-line treatment against type II diabetes, or chlorhexidine, the gold

Stereoselective synthesis and transformation of pinane-based 2-amino-1,3-diols

• Ákos Bajtel,
• Mounir Raji,
• Matti Haukka,
• Ferenc Fülöp and
• Zsolt Szakonyi

Beilstein J. Org. Chem. 2021, 17, 983–990, doi:10.3762/bjoc.17.80

• the regioisomers of potential monoterpenic 2-amino-1,3-diols [29][30][31][32][33]. These trifunctionalized terpenoids may also possess diverse biological activities and could successfully applied as chiral catalysts in enantioselective transformations [34]. In the present study, our aim was to

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

• . Tacrine (1) is an acridine derivative used in the treatment of Alzheimer’s disease. A plethora of acridine derivatives have been synthesized and clinically proved with various biological activities such as ethacridine (antibacterial drug; 2), acranil (antiviral drug; 3) and quinacrine (antimalarial agent

• (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

• phenanthroline. 6 Pyrimidines/fused pyrimidines 6.1 Pyrimidines Pyrimidines are six-membered aromatic heterocycles containing two nitrogen atoms at positions 1 and 3. These are an important class of compounds depicting a wide range of biological activities such as COX inhibitors, anti-inflammatory, anticancer

Synthesis of β-triazolylenones via metal-free desulfonylative alkylation of N-tosyl-1,2,3-triazoles

• Soumyaranjan Pati,
• Renata G. Almeida,
• Eufrânio N. da Silva Júnior and
• Irishi N. N. Namboothiri

Beilstein J. Org. Chem. 2021, 17, 762–770, doi:10.3762/bjoc.17.66

• , cefatrizine, rufinamide and JNJ-54175446 (Scheme 1a) [10]. In addition to their biological activities, triazolic compounds are widely employed in organic synthesis and have outstanding synthetic versatility. In this sense, extensive scientific research has been conducted using triazoles as synthetic

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

• -aminopyrroloquinolines with various biological activities. Keywords: 2-azahexatiriene system; carbodiimide; electrocyclization; pyrrolo[2,3-c]quinoline; trigonoine B; Introduction In 2011, two novel alkaloids, namely trigonoine A and B, were isolated from the leaves of Trigonostemon lii by Hao and co-workers [1]. The

•  1). These pyrrolo[2,3-c]quinolines have been demonstrated to show antimalarial and antibacterial biological activities [2][3][4]. Thus, the development of a convenient and efficient synthetic route to the pyrrolo[2,3-c]quinoline skeleton has attracted considerable attention from organic and

Stereoselective syntheses of 3-aminocyclooctanetriols and halocyclooctanetriols

• Emine Salamci and
• Yunus Zozik

Beilstein J. Org. Chem. 2021, 17, 705–710, doi:10.3762/bjoc.17.59

• are also cyclitol derivatives, in which one of the hydroxy groups is replaced by a halogen. They have also attracted interest in the last decade because of their biological activities [11][19]. For instance, some brominated quercitol (cyclohexanepentol) derivatives and bromoconduritol-B act as strong

• biological activities [1][2][3][16][17][18][19][20][21][22][23][24][25][26]. However, only a limited number of synthetic methods are available for the synthesis of seven- [27][28], eight- [29][30][31][32][33][34][35][36][37][38], and nine- [35] membered aminocyclitols. Therefore, we were inspired to work on

Designed whole-cell-catalysis-assisted synthesis of 9,11-secosterols

• Marek Kõllo,
• Marje Kasari,
• Villu Kasari,
• Tõnis Pehk,
• Ivar Järving,
• Margus Lopp,
• Arvi Jõers and
• Tõnis Kanger

Beilstein J. Org. Chem. 2021, 17, 581–588, doi:10.3762/bjoc.17.52

• Pseudopterogorgia americana in 1972 (Figure 1B) [7], several others from the family have been reported [8][9][10][11][12][13][14]. The 9,11-secosterols exhibit diverse biological activities, including antihistaminic, antiproliferative, anti-inflammatory, cytotoxic and protein kinase C (PKC) inhibition activities [8

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

• (Scheme 1A) [2]. The antibacterial principle in garlic was identified in 1944 by Cavallito et al. as allicin (5) [3], a formal oxidation product of disulfide 2. Not only 5, but also several other sulfur compounds from garlic are today known to exhibit diverse biological activities, including inter alia

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

• ring at the C6 position of purine to act as leaving group. Keywords: 2,6-bistriazolyl purines; nucleophilic aromatic substitution; purine nucleosides; triazoles; Introduction Modified purine derivatives are an important class of compounds which possess a wide spectrum of biological activities [1][2

Facile preparation and conversion of 4,4,4-trifluorobut-2-yn-1-ones to aromatic and heteroaromatic compounds

• Takashi Yamazaki,
• Yoh Nakajima,
• Minato Iida and
• Tomoko Kawasaki-Takasuka

Beilstein J. Org. Chem. 2021, 17, 132–138, doi:10.3762/bjoc.17.14

• ; salicylate derivatives; Introduction It is well known that the incorporation of a fluorine atom or a fluorine-containing group into organic compounds sometimes affects their original biological activities [1][2][3], and thus the development of methods for the construction of such molecules with this atom or

Progress in the total synthesis of inthomycins

• Bidyut Kumar Senapati

Beilstein J. Org. Chem. 2021, 17, 58–82, doi:10.3762/bjoc.17.7

• polyene chiral allylic β-hydroxycarbonyl fragments and significant biological activities. The full structural motif of the inthomycins is found in several more complex natural products including the oxazolomycins, 16-methyloxazolomycin, curromycins A and B, and KSM-2690. This review summarises the

• ) are embodied in several other naturally occurring compounds, such as neooxazolomycin (4), oxazolomycins A–C (5, 6) [9][10][11][12][13][14], curromycins (7) [15], and KSM-2690 (8) [16] (Figure 1). Owing to their various biological activities and characteristic closely related structural motifs, they

• interesting structures accompanied by their promising biological activities and the lack of natural sources have made inthomycins an attractive target in the synthetic organic community to work intensively in this area. The synthesis of simple looking inthomycins is challenging due to the unusually interposed

An atom-economical addition of methyl azaarenes with aromatic aldehydes via benzylic C(sp³)–H bond functionalization under solvent- and catalyst-free conditions

• Divya Rohini Yennamaneni,
• Vasu Amrutham,
• Krishna Sai Gajula,
• Rammurthy Banothu,
• Murali Boosa and
• Narender Nama

Beilstein J. Org. Chem. 2020, 16, 3093–3103, doi:10.3762/bjoc.16.259

• dehydrated alkenyl products were obtained, which may possess wide biological activities of great demand. This reaction was also carried out on a gram scale, and the results display the potential for large-scale applications as the yields were not drastically changed when shifting from a mmol scale to a gram

Chemical constituents of Chaenomeles sinensis twigs and their biological activity

• Joon Min Cha,
• Dong Hyun Kim,
• Lalita Subedi,
• Zahra Khan,
• Sang Un Choi,
• Sun Yeou Kim and
• Chung Sub Kim

Beilstein J. Org. Chem. 2020, 16, 3078–3085, doi:10.3762/bjoc.16.257

• continuing search for cytotoxic, antineuroinflammatory, and neurotrophic secondary metabolites from C. sinensis [13][14][15][21], the isolates (1–12) were tested for these biological activities. The cytotoxicity was evaluated on the basis of the growth inhibitory effects of the isolated compounds 1–12

Regioselective synthesis of heterocyclic N-sulfonyl amidines from heteroaromatic thioamides and sulfonyl azides

• Vladimir Ilkin,
• Vera Berseneva,
• Tetyana Beryozkina,
• Tatiana Glukhareva,
• Lidia Dianova,
• Wim Dehaen,
• Eugenia Seliverstova and
• Vasiliy Bakulev

Beilstein J. Org. Chem. 2020, 16, 2937–2947, doi:10.3762/bjoc.16.243

• , antibiotics and in many types of synthetic drugs [1][2][3][4][5][6][7][8][9][10][11][12]. N-Sulfonyl amidines have received considerable attention because they exhibit various types of pharmaceutical properties and biological activities [13][14][15][16][17][18][19][20][21] and also have been used as

A novel and robust heterogeneous Cu catalyst using modified lignosulfonate as support for the synthesis of nitrogen-containing heterocycles

• Bingbing Lai,
• Meng Ye,
• Ping Liu,
• Minghao Li,
• Rongxian Bai and
• Yanlong Gu

Beilstein J. Org. Chem. 2020, 16, 2888–2902, doi:10.3762/bjoc.16.238

• activity in organic reactions. Tricyclic indole alkaloids bearing 3,4-fused seven-membered rings have attracted much attention because of their interesting molecular architectures and important biological activities [32][33]. Here the three-component reaction of 4-aminoindole (1a), 4-methylbenzaldehyde (2a

Fluorine effect in nucleophilic fluorination at C4 of 1,6-anhydro-2,3-dideoxy-2,3-difluoro-β-D-hexopyranose

• Danny Lainé,
• Vincent Denavit,
• Olivier Lessard,
• Laurie Carrier,
• Charles-Émile Fecteau,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2020, 16, 2880–2887, doi:10.3762/bjoc.16.237

• biological activities of heavily fluorinated carbohydrates [19][21][22][23][24][25]. With intermediates 2–5 in hand, we studied the reactivities of a small set of chirally distinct difluorinated 1,6-anhydro-β-ᴅ-hexopyranose analogues. We aimed to explore the difference in reactivities of compounds 2–5 under