Diversity-oriented synthesis of 17-spirosteroids

• Benjamin Laroche,
• Thomas Bouvarel,
• Martin Louis-Sylvestre and
• Bastien Nay

Beilstein J. Org. Chem. 2020, 16, 880–887, doi:10.3762/bjoc.16.79

• biologically validated scaffolds [8][9][10], referred to as privileged structures in medicinal chemistry [11][12][13][14]. Spanning unexplored chemical space, DOS strategies have been successfully applied to the generation of biologically active libraries for screening, leading to the discovery of medicinally

Preparation of 2-phospholene oxides by the isomerization of 3-phospholene oxides

• Péter Bagi,
• Réka Herbay,
• Nikolett Péczka,
• Zoltán Mucsi,
• István Timári and
• György Keglevich

Beilstein J. Org. Chem. 2020, 16, 818–832, doi:10.3762/bjoc.16.75

• -coupled transformations [18][22][23]. Polycyclic compounds incorporating a P-heterocyclic moiety are of special importance due to their optoelectronic properties and applications [24][25][26]. Moreover, a few biologically active 5-membered P-heterocyclic derivatives are also known, which showed promising

• importance for biologically active compounds, as specific functional groups are necessary to have a desired biological activity. Considering the functionalization of the five-membered P-heterocycles, the derivatives containing double bond(s) (i.e., phospholenes or phospholes) are of special importance, as a

• × 3.0 mL dichloromethane. The organic phase dried (Na2SO4), evaporated to give 0.15 g (81%) of 1-phenyl-3-methyl-2-phospholene oxide (4a). The results are summarized in Table 2 and Scheme 1. Examples for catalytically or biologically active molecules containing five-membered P-heterocyclic rings

Efficient synthesis of piperazinyl amides of 18β-glycyrrhetinic acid

• Dong Cai,
• ZhiHua Zhang,
• Yufan Meng,
• KaiLi Zhu,
• LiYi Chen,
• ChangXiang Yu,
• ChangWei Yu,
• ZiYi Fu,
• DianShen Yang and
• YiXia Gong

Beilstein J. Org. Chem. 2020, 16, 798–808, doi:10.3762/bjoc.16.73

• agent [12]. Piperazinyl amide fragments have the ability to form several hydrogen bonds, modulate the acid–base equilibrium constant and change the octanol–water partition coefficient [13]. They are considered as the basic motif for designing many biologically active molecules [14][15]. Some piperazinyl

• %) without the formation of byproducts [21]. Given the flexible 18β-glycyrrhetinic acid scaffold in the design of biologically active compounds, a novel and efficient method was reported to prepare C3 ester derivatives or/and C30 piperazinyl amides (c). 18β-Glycyrrhetinic acid belongs to the class of ursane

• biologically active substances. According to the first method, compound 12 reacted with morpholine in the presence of K2CO3/I2 to give compound 13, followed by successive amidation and N-Boc deprotection gave compound 17. It is noteworthy that the carboxyl group of compound 12 did not react with inorganic

Reaction of indoles with aromatic fluoromethyl ketones: an efficient synthesis of trifluoromethyl(indolyl)phenylmethanols using K₂CO₃/n-Bu₄PBr in water

• Thanigaimalai Pillaiyar,
• Masoud Sedaghati and
• Gregor Schnakenburg

Beilstein J. Org. Chem. 2020, 16, 778–790, doi:10.3762/bjoc.16.71

• the catalytic system and large-scale synthesis of products, which would further transform into biologically active indole-derived compounds, are further advantages of this protocol. Structures of trifluoromethylated compounds and their biological activities. Synthetic approaches toward

Efficient synthesis of dipeptide analogues of α-fluorinated β-aminophosphonates

• Marcin Kaźmierczak and
• Henryk Koroniak

Beilstein J. Org. Chem. 2020, 16, 756–762, doi:10.3762/bjoc.16.69

• biologically active compounds. As an example, we can consider peptide bond formation between an amine and a carboxylic acid. This transformation is a very important reaction in organic synthesis and therefore, many coupling reagents are available on the market [25][26][27][28][29]. Our previous studies have

Towards the total synthesis of chondrochloren A: synthesis of the (Z)-enamide fragment

• Jan Geldsetzer and
• Markus Kalesse

Beilstein J. Org. Chem. 2020, 16, 670–673, doi:10.3762/bjoc.16.64

• ′-dimethylethane-1,2-diamine. Keywords: cross coupling; myxobacteria; natural product; ribolactone; Z-enamide; Introduction In the course of our program to provide synthetic access to biologically active natural products we targeted complex polyketides and depsipetides [1][2][3][4][5][6][7][8][9][10]. One

Cascade trifluoromethylthiolation and cyclization of N-[(3-aryl)propioloyl]indoles

• Ming-Xi Bi,
• Shuai Liu,
• Yangen Huang,
• Xiu-Hua Xu and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2020, 16, 657–662, doi:10.3762/bjoc.16.62

• , especially those featuring medicinally promising scaffolds. Pyrrolo[1,2-a]indol-3-ones are prevalent scaffolds that widely exist in many bioactive compounds and natural products [17][18][19][20]. Representative examples of biologically active pyrrolo[1,2-a]indol-3-one derivatives are shown in Figure 1

• converted to the mono(trifluoromethylthiolated) products in moderate yields. Further studies on applying radical cascade reactions to the construction of fluorine-containing heterocyclic scaffolds are in progress in our laboratory. Representative examples of biologically active pyrrolo[1,2-a]indol-3-one

Rhodium-catalyzed reductive carbonylation of aryl iodides to arylaldehydes with syngas

• Zhenghui Liu,
• Peng Wang,
• Zhenzhong Yan,
• Suqing Chen,
• Dongkun Yu,
• Xinhui Zhao and
• Tiancheng Mu

Beilstein J. Org. Chem. 2020, 16, 645–656, doi:10.3762/bjoc.16.61

• preparation of biologically active molecules or their intermediates [28][29]. Generally, aromatic aldehydes are synthesized by Reimer–Tiemann, Gattermann–Koch, Vielsmeier–Haag, or Duff reactions and so forth. Unfortunately, these reactions usually use auxiliary reagents and thus generate large amounts of

Synthesis of 4-(2-fluorophenyl)-7-methoxycoumarin: experimental and computational evidence for intramolecular and intermolecular C–F···H–C bonds

• Vuyisa Mzozoyana,
• Fanie R. van Heerden and
• Craig Grimmer

Beilstein J. Org. Chem. 2020, 16, 190–199, doi:10.3762/bjoc.16.22

• of biologically active compounds as it imparts a variety of properties such as enhanced binding interaction, metabolic stability, and reaction selectivity by changing physical and chemical properties [23][24][25][26]. Hydrogen bonds (HBs) are associated with highly electronegative atoms (oxygen

Efficient method for propargylation of aldehydes promoted by allenylboron compounds under microwave irradiation

• Jucleiton J. R. Freitas,
• Queila P. S. B. Freitas,
• Silvia R. C. P. Andrade,
• Juliano C. R. Freitas,
• Roberta A. Oliveira and
• Paulo H. Menezes

Beilstein J. Org. Chem. 2020, 16, 168–174, doi:10.3762/bjoc.16.19

• ; synthesis; Introduction The propargylation of carbonyl compounds is widely used in the synthesis of biologically active natural products [1]. Some examples can be found in the synthesis of histrionicotoxin [2], rhizopodin [3], bafilomycin [4], bryostatin [5], vancosamine [6] and macrolactin A [7]. Although

Rapid, two-pot procedure for the synthesis of dihydropyridinones; total synthesis of aza-goniothalamin

• Thomas J. Cogswell,
• Craig S. Donald and
• Rodolfo Marquez

Beilstein J. Org. Chem. 2020, 16, 135–139, doi:10.3762/bjoc.16.15

• biologically active compounds. As a result, their synthesis has received extensive research and wide spread publication in the literature [1][2][3][4][5][6]. Dihydropyridinones are an important subclass of heterocycles, which often feature both as useful intermediates, and as interesting species in their own

Light-controllable dithienylethene-modified cyclic peptides: photoswitching the in vivo toxicity in zebrafish embryos

• Sergii Afonin,
• Oleg Babii,
• Aline Reuter,
• Volker Middel,
• Masanari Takamiya,
• Uwe Strähle,
• Igor V. Komarov and
• Anne S. Ulrich

Beilstein J. Org. Chem. 2020, 16, 39–49, doi:10.3762/bjoc.16.6

• ; membrane-active peptides; photopharmacology; zebrafish embryotoxicity model; Introduction Biologically-active peptides as a class of chemotherapeutic compounds are uniquely positioned between traditional small organic molecule drugs and high-molecular weight biologics [1][2]. Since recent breakthroughs in

Extension of the 5-alkynyluridine side chain via C–C-bond formation in modified organometallic nucleosides using the Nicholas reaction

• Renata Kaczmarek,
• Dariusz Korczyński,
• James R. Green and
• Roman Dembinski

Beilstein J. Org. Chem. 2020, 16, 1–8, doi:10.3762/bjoc.16.1

• warranted, which at the same time may provide biologically active compounds. Results and Discussion Preparation of 5-alkynyluridines was carried out from acyl-protected 5-iodouridines (1a,b) [8][63] and the appropriate terminal alkyne in the presence of catalytic amounts of Pd(PPh3)4, copper(I) iodide

SnCl₄-catalyzed solvent-free acetolysis of 2,7-anhydrosialic acid derivatives

• Kesatebrhan Haile Asressu and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2019, 15, 2990–2999, doi:10.3762/bjoc.15.295

• University, Hsinchu 300, Taiwan 10.3762/bjoc.15.295 Abstract Sialic acid-containing glycans are found in different sialic acid forms and a variety of glycosidic linkages in biologically active glycoconjugates. Hence, the preparation of suitably protected sialyl building blocks requires high attention in

Pigmentosins from Gibellula sp. as antibiofilm agents and a new glycosylated asperfuran from Cordyceps javanica

• Soleiman E. Helaly,
• Wilawan Kuephadungphan,
• Patima Phainuphong,
• Mahmoud A. A. Ibrahim,
• Kanoksri Tasanathai,
• Suchada Mongkolsamrit,
• Janet Jennifer Luangsa-ard,
• Souwalak Phongpaichit,
• Vatcharin Rukachaisirikul and
• Marc Stadler

Beilstein J. Org. Chem. 2019, 15, 2968–2981, doi:10.3762/bjoc.15.293

• , Thailand Department of Chemistry, Faculty of Science, Prince of Songkla University, Songkhla 90112, Thailand 10.3762/bjoc.15.293 Abstract In the course of our exploration of the Thai invertebrate-pathogenic fungi for biologically active metabolites, pigmentosin A (1) and a new bis(naphtho-α-pyrone

Construction of trisubstituted chromone skeletons carrying electron-withdrawing groups via PhIO-mediated dehydrogenation and its application to the synthesis of frutinone A

• Qiao Li,
• Chen Zhuang,
• Donghua Wang,
• Wei Zhang,
• Rongxuan Jia,
• Fengxia Sun,
• Yilin Zhang and
• Yunfei Du

Beilstein J. Org. Chem. 2019, 15, 2958–2965, doi:10.3762/bjoc.15.291

• further applied to the synthesis of the naturally occurring frutinone A. Biologically active chromone derivatives. Methods for the synthesis of chromones via dehydrogenative oxidation of chromanones. Substrate scope studies. Reaction conditions: 1 (1.0 mmol), PhIO (2.0 mmol), DMF (6 mL), rt. Isolated

Why do thioureas and squaramides slow down the Ireland–Claisen rearrangement?

• Dominika Krištofíková,
• Juraj Filo,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2019, 15, 2948–2957, doi:10.3762/bjoc.15.290

• base [1][2][3]. The products of the Ireland–Claisen rearrangement, γ,δ-unsaturated acids, are useful precursors of biologically active compounds and natural products [4][5][6][7][8][9][10][11]. The ready availability of allylic esters, the ability to control the E/Z geometry of enolates as well as its

Facile regiodivergent synthesis of spiro pyrrole-substituted pseudothiohydantoins and thiohydantoins via reaction of [e]-fused 1H-pyrrole-2,3-diones with thiourea

• Aleksandr I. Kobelev,
• Nikita A. Tretyakov,
• Ekaterina E. Stepanova,
• Maksim V. Dmitriev,
• Michael Rubin and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2019, 15, 2864–2871, doi:10.3762/bjoc.15.280

• good yields, and the products were isolated without applying preparative chromatography methods. Keywords: diversity-oriented synthesis; hydantoin; nitrogen heterocycles; rearrangement; thiourea; Introduction Hydantoin (imidazolidine-2,4-dione) derivatives are omnipresent among biologically active

Skeletocutins M–Q: biologically active compounds from the fruiting bodies of the basidiomycete Skeletocutis sp. collected in Africa

• Tian Cheng,
• Clara Chepkirui,
• Cony Decock,
• Josphat C. Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2019, 15, 2782–2789, doi:10.3762/bjoc.15.270

Diversity-oriented synthesis of spirothiazolidinediones and their biological evaluation

• Sambasivarao Kotha,
• Gaddamedi Sreevani,
• Lilya U. Dzhemileva,
• Milyausha M. Yunusbaeva,
• Usein M. Dzhemilev and
• Vladimir A. D’yakonov

Beilstein J. Org. Chem. 2019, 15, 2774–2781, doi:10.3762/bjoc.15.269

• inducers in the HeLa, Hek293, U937, Jurkat, and K562 cell lines. Keywords: apoptosis; biologically active; [2 + 2 + 2] cycloaddition; flow cytometry; spiro thiazolidinedione; Introduction Heterocyclic compounds play a vital role in the metabolism of all living cells. Thus, most of the biologically active

• represent an important class of nitrogen-containing biologically active compounds which exhibit various biological properties, such as antiviral, antibacterial and anticancer, etc. [55][56][57][58]. Recently, the use of 1,2,3-triazole derivatives as drug candidates has been increased for clinical therapy of

Fluorinated maleimide-substituted porphyrins and chlorins: synthesis and characterization

• Valentina A. Ol’shevskaya,
• Elena G. Kononova and
• Andrei V. Zaitsev

Beilstein J. Org. Chem. 2019, 15, 2704–2709, doi:10.3762/bjoc.15.263

• 1,2,3-triazole heterocycles via the copper-catalyzed azide–alkyne cycloaddition reaction (CuAAC) between alkynes and azides, developed independently by Sharpless [41] and Meldal [42]. In addition to the applications of triazoles as pharmacophores in the potential biologically active molecules, these

AgNTf₂-catalyzed formal [3 + 2] cycloaddition of ynamides with unprotected isoxazol-5-amines: efficient access to functionalized 5-amino-1H-pyrrole-3-carboxamide derivatives

• Ziping Cao,
• Jiekun Zhu,
• Li Liu,
• Yuanling Pang,
• Laijin Tian,
• Xuejun Sun and
• Xin Meng

Beilstein J. Org. Chem. 2019, 15, 2623–2630, doi:10.3762/bjoc.15.255

• catalyst, mild reaction conditions, simple operation and product purification. Notably, the core skeleton of these products is the substructure of many biologically active molecules. For example (Figure 1), compound 1 has significant activities as DNA-cleaving agent [39] and sangivamycin 2 has been in

An overview of the cycloaddition chemistry of fulvenes and emerging applications

• Ellen Swan,
• Kirsten Platts and
• Anton Blencowe

Beilstein J. Org. Chem. 2019, 15, 2113–2132, doi:10.3762/bjoc.15.209

• al. developed a programmable enantioselective one-pot synthesis of molecules with eight stereocentres greatly improving the efficiency of natural product synthesis [83]. Each of these natural products are biologically active, hence their total synthesis will allow further characterisation of their

Friedel–Crafts approach to the one-pot synthesis of methoxy-substituted thioxanthylium salts

• Kenta Tanaka,
• Yuta Tanaka,
• Mami Kishimoto,
• Yujiro Hoshino and
• Kiyoshi Honda

Beilstein J. Org. Chem. 2019, 15, 2105–2112, doi:10.3762/bjoc.15.208

• . Keywords: Friedel–Crafts reaction; metal-free conditions; one-pot synthesis; photoredox catalyst; thioxanthylium salt; Introduction Thioxanthylium salts are one of the important structural motifs found in biologically active compounds and photochemical materials [1][2][3][4][5][6][7][8]. Owing to these

Installation of -SO₂F groups onto primary amides

• Jing Liu,
• Shi-Meng Wang,
• Njud S. Alharbi and
• Hua-Li Qin

Beilstein J. Org. Chem. 2019, 15, 1907–1912, doi:10.3762/bjoc.15.186

• , and a vast number of synthetic structures, such as polymers, biologically active compounds and pharmaceutical products [32][33][34][35]. However, the installation of sulfonyl fluoride (SO2F) onto nitrogen atoms of amides has not been achieved, which, if accomplished, would provide a very important